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ViewCellBsp.cpp @ 2609

Revision 2609, 83.1 KB checked in by mattausch, 17 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include "Triangle3.h"
11	#include "Tetrahedron3.h"
12	#include "ViewCellsManager.h"
13	#include "Exporter.h"
14	#include "Plane3.h"
15	#include <stack>
16
17	namespace GtpVisibilityPreprocessor {
18
19	//////////////
20	//-- static members
21
22	int BspNode::sMailId = 1;
23
24	/** Evaluates split plane classification with respect to the plane's
25	contribution for a minimum number splits in the tree.
26	*/
27	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
28	/** Evaluates split plane classification with respect to the plane's
29	contribution for a balanced tree.
30	*/
31	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
32
33	/** Evaluates split plane classification with respect to the plane's
34	contribution for a minimum number of ray splits.
35	*/
36	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
37	/** Evaluates split plane classification with respect to the plane's
38	contribution for balanced rays.
39	*/
40	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
41
42	int BspTree::sFrontId = 0;
43	int BspTree::sBackId = 0;
44	int BspTree::sFrontAndBackId = 0;
45
46
47	/******************************************************************/
48	/* class BspNode implementation */
49	/******************************************************************/
50
51
52	BspNode::BspNode():
53	mParent(NULL), mTreeValid(true), mTimeStamp(0)
54	{}
55
56
57	BspNode::BspNode(BspInterior *parent):
58	mParent(parent), mTreeValid(true)
59	{}
60
61
62	bool BspNode::IsSibling(BspNode *n) const
63	{
64	return ((this != n) && mParent &&
65	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
66	}
67
68
69	int BspNode::GetDepth() const
70	{
71	int depth = 0;
72	BspNode *p = mParent;
73
74	while (p)
75	{
76	p = p->mParent;
77	++ depth;
78	}
79
80	return depth;
81	}
82
83
84	bool BspNode::TreeValid() const
85	{
86	return mTreeValid;
87	}
88
89
90	void BspNode::SetTreeValid(const bool v)
91	{
92	mTreeValid = v;
93	}
94
95
96	/****************************************************************/
97	/* class BspInterior implementation */
98	/****************************************************************/
99
100
101	BspInterior::BspInterior(const Plane3 &plane):
102	mPlane(plane), mFront(NULL), mBack(NULL)
103	{}
104
105
106	BspInterior::~BspInterior()
107	{
108	DEL_PTR(mFront);
109	DEL_PTR(mBack);
110	}
111
112
113	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
114	{
115	mBack = b;
116	mFront = f;
117	}
118
119
120	/****************************************************************/
121	/* class BspLeaf implementation */
122	/****************************************************************/
123
124
125	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
126	{
127	}
128
129
130	BspLeaf::~BspLeaf()
131	{
132	DEL_PTR(mPvs);
133
134	VssRayContainer::const_iterator vit, vit_end = mVssRays.end();
135	for (vit = mVssRays.begin(); vit != vit_end; ++ vit)
136	{
137	VssRay ray = vit;
138	ray->Unref();
139
140	if (!ray->IsActive())
141	delete ray;
142	}
143	}
144
145
146	BspLeaf::BspLeaf(ViewCellLeaf *viewCell):
147	mViewCell(viewCell)
148	{
149	}
150
151
152	BspLeaf::BspLeaf(BspInterior *parent):
153	BspNode(parent), mViewCell(NULL), mPvs(NULL)
154	{}
155
156
157
158	BspLeaf::BspLeaf(BspInterior parent, ViewCellLeaf viewCell):
159	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
160	{
161	}
162
163
164	/*********************************************************************/
165	/* class BspTree implementation */
166	/*********************************************************************/
167
168	BspTree::BspTree():
169	mRoot(NULL),
170	mUseAreaForPvs(false),
171	mUsePredefinedViewCells(false),
172	mTimeStamp(1),
173	mViewCellsTree(NULL),
174	mOutOfBoundsCellPartOfTree(false),
175	mOutOfBoundsCell(NULL)
176	{
177	Randomize(); // initialise random generator for heuristics
178	mOutOfBoundsCell = GetOrCreateOutOfBoundsCell();
179
180	/////////
181	//-- termination criteria for autopartition
182
183	Environment::GetSingleton()->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
184	Environment::GetSingleton()->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
185	Environment::GetSingleton()->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
186	Environment::GetSingleton()->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
187	Environment::GetSingleton()->GetFloatValue("BspTree.Termination.minProbability", mTermMinProbability);
188	Environment::GetSingleton()->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
189	Environment::GetSingleton()->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
190
191
192	/////////
193	//-- factors for bsp tree split plane heuristics
194
195	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
196	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
197	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
198	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
199	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
200	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
201	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
202	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
203	Environment::GetSingleton()->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
204	Environment::GetSingleton()->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
205
206
207	///////////
208	//-- termination criteria for axis aligned split
209
210	Environment::GetSingleton()->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
211	Environment::GetSingleton()->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
212	Environment::GetSingleton()->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
213	mTermMinPolysForAxisAligned);
214	Environment::GetSingleton()->GetIntValue("BspTree.Termination.AxisAligned.minRays",
215	mTermMinRaysForAxisAligned);
216	Environment::GetSingleton()->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
217	mTermMinObjectsForAxisAligned);
218
219
220	//////////////
221	//-- partition criteria
222
223	Environment::GetSingleton()->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
224	Environment::GetSingleton()->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
225	Environment::GetSingleton()->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
226	Environment::GetSingleton()->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
227	Environment::GetSingleton()->GetIntValue("BspTree.maxTests", mMaxTests);
228	Environment::GetSingleton()->GetIntValue("BspTree.Termination.maxViewCells", mMaxViewCells);
229
230	Environment::GetSingleton()->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
231
232	char subdivisionStatsLog[100];
233	Environment::GetSingleton()->GetStringValue("BspTree.subdivisionStats", subdivisionStatsLog);
234	mSubdivisionStats.open(subdivisionStatsLog);
235
236	/////////////////////7
237
238	Debug << "BSP options: " << endl;
239	Debug << "BSP max depth: " << mTermMaxDepth << endl;
240	Debug << "BSP min PVS: " << mTermMinPvs << endl;
241	Debug << "BSP min probability: " << mTermMinProbability << endl;
242	Debug << "BSP max polys: " << mTermMinPolys << endl;
243	Debug << "BSP max rays: " << mTermMinRays << endl;
244	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
245	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
246
247	Debug << "Split plane strategy: ";
248	if (mSplitPlaneStrategy & RANDOM_POLYGON)
249	Debug << "random polygon ";
250	if (mSplitPlaneStrategy & AXIS_ALIGNED)
251	Debug << "axis aligned ";
252	if (mSplitPlaneStrategy & LEAST_SPLITS)
253	Debug << "least splits ";
254	if (mSplitPlaneStrategy & BALANCED_POLYS)
255	Debug << "balanced polygons ";
256	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
257	Debug << "balanced view cells ";
258	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
259	Debug << "largest polygon area ";
260	if (mSplitPlaneStrategy & VERTICAL_AXIS)
261	Debug << "vertical axis ";
262	if (mSplitPlaneStrategy & BLOCKED_RAYS)
263	Debug << "blocked rays ";
264	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
265	Debug << "least ray splits ";
266	if (mSplitPlaneStrategy & BALANCED_RAYS)
267	Debug << "balanced rays ";
268	if (mSplitPlaneStrategy & PVS)
269	Debug << "pvs";
270
271	Debug << endl;
272	}
273
274
275	bool BspTree::IsOutOfBounds(ViewCell *vc) const
276	{
277	return vc->GetId() == OUT_OF_BOUNDS_ID;
278	}
279
280
281	const BspTreeStatistics &BspTree::GetStatistics() const
282	{
283	return mStat;
284	}
285
286
287	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
288	{
289	if (!mOutOfBoundsCell)
290	{
291	mOutOfBoundsCell = new BspViewCell();
292	mOutOfBoundsCell->SetId(OUT_OF_BOUNDS_ID);
293	mOutOfBoundsCell->SetValid(false);
294	}
295
296	return mOutOfBoundsCell;
297	}
298
299	int BspTree::SplitPolygons(const Plane3 &plane,
300	PolygonContainer &polys,
301	PolygonContainer &frontPolys,
302	PolygonContainer &backPolys,
303	PolygonContainer &coincident) const
304	{
305	int splits = 0;
306
307	#ifdef _Debug
308	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
309	#endif
310
311	PolygonContainer::const_iterator it, it_end = polys.end();
312
313	for (it = polys.begin(); it != polys.end(); ++ it)
314	{
315	Polygon3 poly = it;
316
317	//-- classify polygon
318	const int cf = poly->ClassifyPlane(plane, mEpsilon);
319
320	switch (cf)
321	{
322	case Polygon3::COINCIDENT:
323	coincident.push_back(poly);
324	break;
325	case Polygon3::FRONT_SIDE:
326	frontPolys.push_back(poly);
327	break;
328	case Polygon3::BACK_SIDE:
329	backPolys.push_back(poly);
330	break;
331	case Polygon3::SPLIT:
332	{
333	Polygon3 *front_piece = new Polygon3(poly->mParent);
334	Polygon3 *back_piece = new Polygon3(poly->mParent);
335
336	//-- split polygon into front and back part
337	poly->Split(plane,
338	*front_piece,
339	*back_piece,
340	mEpsilon);
341
342	++ splits; // increase number of splits
343
344	//-- inherit rays from parent polygon for blocked ray criterium
345	poly->InheritRays(front_piece, back_piece);
346
347	// check if polygons still valid
348	if (front_piece->Valid(mEpsilon))
349	frontPolys.push_back(front_piece);
350	else
351	DEL_PTR(front_piece);
352
353	if (back_piece->Valid(mEpsilon))
354	backPolys.push_back(back_piece);
355	else
356	DEL_PTR(back_piece);
357
358	#ifdef GTP_DEBUG
359	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
360	#endif
361	DEL_PTR(poly);
362	}
363	break;
364	default:
365	Debug << "SHOULD NEVER COME HERE\n";
366	break;
367	}
368	}
369
370	return splits;
371	}
372
373
374	void BspTreeStatistics::Print(ostream &app) const
375	{
376	app << "===== BspTree statistics ===============\n";
377
378	app << setprecision(4);
379
380	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
381
382	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
383
384	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
385
386	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
387
388	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
389
390	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
391
392	app << "#N_SPLITS ( Number of splits in axes x y z)\n";
393
394	for (int i = 0; i < 3; ++ i)
395	app << splits[i] << " ";
396	app << endl;
397
398	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
399	<< maxDepthNodes * 100 / (double)Leaves() << endl;
400
401	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
402	<< minPvsNodes * 100 / (double)Leaves() << endl;
403
404	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
405	<< minRaysNodes * 100 / (double)Leaves() << endl;
406
407	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
408	<< maxCostNodes * 100 / (double)Leaves() << endl;
409
410	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
411	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
412
413	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
414	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
415
416	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
417
418	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
419
420	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
421
422	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
423
424	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
425
426	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
427	//app << "#N_PVS: " << pvs << endl;
428
429	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
430	(polys + polySplits) / (double)polys << endl;
431
432	app << "===== END OF BspTree statistics ==========\n";
433	}
434
435
436	BspTree::~BspTree()
437	{
438	DEL_PTR(mRoot);
439
440	if (!mOutOfBoundsCellPartOfTree)
441	{
442	// out of bounds cell not part of tree =>
443	// delete manually
444	DEL_PTR(mOutOfBoundsCell);
445	}
446	}
447
448
449	BspNode *BspTree::GetRoot() const
450	{
451	return mRoot;
452	}
453
454
455	void BspTree::SetViewCellsTree(ViewCellsTree *viewCellsTree)
456	{
457	mViewCellsTree = viewCellsTree;
458	}
459
460
461	void BspTree::InsertViewCell(ViewCellLeaf *viewCell)
462	{
463	// don't generate new view cell, insert this view cell
464	mUsePredefinedViewCells = true;
465	PolygonContainer *polys = new PolygonContainer();
466
467	// extract polygons that guide the split process
468	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
469	mBbox.Include(viewCell->GetBox()); // add to BSP aabb
470
471	InsertPolygons(polys);
472	}
473
474
475	void BspTree::InsertPolygons(PolygonContainer *polys)
476	{
477	BspTraversalStack tStack;
478
479	// traverse existing tree or create new tree
480	if (!mRoot)
481	mRoot = new BspLeaf();
482
483	tStack.push(BspTraversalData(mRoot,
484	polys,
485	0,
486	mOutOfBoundsCell,
487	new BoundedRayContainer(),
488	0,
489	mUseAreaForPvs ? mBbox.SurfaceArea() : mBbox.GetVolume(),
490	new BspNodeGeometry()));
491
492	while (!tStack.empty())
493	{
494	// filter polygons donw the tree
495	BspTraversalData tData = tStack.top();
496	tStack.pop();
497
498	if (!tData.mNode->IsLeaf())
499	{
500	BspInterior interior = static_cast<BspInterior >(tData.mNode);
501
502	///////////////////
503	//-- filter view cell polygons down the tree until a leaf is reached
504	if (!tData.mPolygons->empty())
505	{
506	PolygonContainer *frontPolys = new PolygonContainer();
507	PolygonContainer *backPolys = new PolygonContainer();
508	PolygonContainer coincident;
509
510	int splits = 0;
511
512	// split viewcell polygons with respect to split plane
513	splits += SplitPolygons(interior->GetPlane(),
514	*tData.mPolygons,
515	*frontPolys,
516	*backPolys,
517	coincident);
518
519	// extract view cells associated with the split polygons
520	ViewCellLeaf *frontViewCell = mOutOfBoundsCell;
521	ViewCellLeaf *backViewCell = mOutOfBoundsCell;
522
523	BspTraversalData frontData(interior->GetFront(),
524	frontPolys,
525	tData.mDepth + 1,
526	mOutOfBoundsCell,
527	tData.mRays,
528	tData.mPvs,
529	mUseAreaForPvs ? mBbox.SurfaceArea() : mBbox.GetVolume(),
530	new BspNodeGeometry());
531
532	BspTraversalData backData(interior->GetBack(),
533	backPolys,
534	tData.mDepth + 1,
535	mOutOfBoundsCell,
536	tData.mRays,
537	tData.mPvs,
538	mUseAreaForPvs ? mBbox.SurfaceArea() : mBbox.GetVolume(),
539	new BspNodeGeometry());
540
541	if (mUsePredefinedViewCells)
542	{
543	ExtractViewCells(frontData,
544	backData,
545	coincident,
546	interior->mPlane);
547	}
548
549	// don't need coincident polygons anymore
550	CLEAR_CONTAINER(coincident);
551
552	mStat.polySplits += splits;
553
554	// push the children on the stack
555	tStack.push(frontData);
556	tStack.push(backData);
557	}
558
559	// cleanup
560	DEL_PTR(tData.mPolygons);
561	DEL_PTR(tData.mRays);
562	}
563	else
564	{
565	// reached leaf => subdivide current viewcell
566	BspNode *subRoot = Subdivide(tStack, tData);
567	}
568	}
569	}
570
571
572	int BspTree::AddMeshToPolygons(Mesh *mesh,
573	PolygonContainer &polys,
574	MeshInstance *parent)
575	{
576	FaceContainer::const_iterator fi, fi_end = mesh->mFaces.end();
577
578	// copy the face data to polygons
579	for (fi = mesh->mFaces.begin(); fi != fi_end; ++ fi)
580	{
581	Polygon3 poly = new Polygon3((fi), mesh);
582
583	if (poly->Valid(mEpsilon))
584	{
585	poly->mParent = parent; // set parent intersectable
586	polys.push_back(poly);
587	}
588	else
589	{
590	DEL_PTR(poly);
591	}
592	}
593	return (int)mesh->mFaces.size();
594	}
595
596
597	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
598	PolygonContainer &polys,
599	int maxObjects)
600	{
601	int limit = (maxObjects > 0) ?
602	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
603
604	int polysSize = 0;
605
606	for (int i = 0; i < limit; ++ i)
607	{
608	Mesh *mesh = viewCells[i]->GetMesh();
609
610	if (mesh)
611	{
612	// copy the mesh into polygons and add to BSP tree aabb
613	mBbox.Include(viewCells[i]->GetBox());
614	polysSize += AddMeshToPolygons(mesh, polys, viewCells[i]);
615	}
616	}
617
618	return polysSize;
619	}
620
621
622	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
623	PolygonContainer &polys,
624	int maxObjects,
625	bool addToBbox)
626	{
627	int limit = (maxObjects > 0) ?
628	Min((int)objects.size(), maxObjects) : (int)objects.size();
629
630	for (int i = 0; i < limit; ++i)
631	{
632	Intersectable *object = objects[i];
633	Mesh *mesh = NULL;
634
635	switch (object->Type()) // extract the meshes
636	{
637	case Intersectable::MESH_INSTANCE:
638	mesh = static_cast<MeshInstance *>(object)->GetMesh();
639	break;
640	case Intersectable::VIEW_CELL:
641	mesh = static_cast<ViewCell *>(object)->GetMesh();
642	break;
643	case Intersectable::TRANSFORMED_MESH_INSTANCE:
644	{
645	TransformedMeshInstance mi = static_cast<TransformedMeshInstance >(object);
646
647	if (!mi->GetMesh())
648	break;
649	mesh = new Mesh();
650	mi->GetTransformedMesh(*mesh);
651	break;
652	}
653	default:
654	Debug << "intersectable type not supported" << endl;
655	break;
656	}
657
658	if (!mesh) continue;
659
660	// copy the mesh data to polygons
661	if (addToBbox)
662	{
663	mBbox.Include(object->GetBox()); // add to BSP tree aabb
664	}
665
666	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
667
668	// cleanup
669	if (object->Type() == Intersectable::TRANSFORMED_MESH_INSTANCE)
670	{
671	DEL_PTR(mesh);
672	}
673	}
674
675	return (int)polys.size();
676	}
677
678
679	void BspTree::Construct(const ViewCellContainer &viewCells)
680	{
681	// construct hierarchy over the given view cells
682	mUsePredefinedViewCells = true;
683
684	mStat.nodes = 1;
685	mBbox.Initialize(); // initialise bsp tree bounding box
686
687	// copy view cell meshes into one big polygon soup
688	PolygonContainer *polys = new PolygonContainer();
689	mStat.polys = AddToPolygonSoup(viewCells, *polys);
690
691	Exporter *expo = Exporter::GetExporter("dummy2.wrl");
692	expo->ExportPolygons(*polys);
693	delete expo;
694	// construct tree from the view cell polygons
695	Construct(polys, new BoundedRayContainer());
696	}
697
698
699	void BspTree::Construct(const ObjectContainer &objects)
700	{
701	// generate new view cells for this type
702	mUsePredefinedViewCells = false;
703
704	mStat.nodes = 1;
705	mBbox.Initialize(); // initialise bsp tree bounding box
706
707	PolygonContainer *polys = new PolygonContainer();
708
709	// copy mesh instance polygons into one big polygon soup
710	mStat.polys = AddToPolygonSoup(objects, *polys);
711
712	// construct tree from polygon soup
713	Construct(polys, new BoundedRayContainer());
714	}
715
716
717	void BspTree::PreprocessPolygons(PolygonContainer &polys)
718	{
719	// preprocess: throw out polygons coincident to the view space box (not needed)
720	PolygonContainer boxPolys;
721	mBbox.ExtractPolys(boxPolys);
722	vector<Plane3> boxPlanes;
723
724	PolygonContainer::iterator pit, pit_end = boxPolys.end();
725
726	// extract planes of box
727	// TODO: can be done more elegantly than here
728	// where we first extract polygons, then compute their planes
729	for (pit = boxPolys.begin(); pit != pit_end; ++ pit)
730	{
731	boxPlanes.push_back((*pit)->GetSupportingPlane());
732	}
733
734	pit_end = polys.end();
735
736	for (pit = polys.begin(); pit != pit_end; ++ pit)
737	{
738	vector<Plane3>::const_iterator bit, bit_end = boxPlanes.end();
739
740	for (bit = boxPlanes.begin(); (bit != bit_end) && (*pit); ++ bit)
741	{
742	const int cf = (pit)->ClassifyPlane(bit, mEpsilon);
743
744	if (cf == Polygon3::COINCIDENT)
745	{
746	DEL_PTR(*pit);
747	//Debug << "coincident!!" << endl;
748	}
749	}
750	}
751
752	// remove deleted entries
753	for (int i = 0; i < (int)polys.size(); ++ i)
754	{
755	while (!polys[i] && (i < (int)polys.size()))
756	{
757	swap(polys[i], polys.back());
758	polys.pop_back();
759	}
760	}
761
762	CLEAR_CONTAINER(boxPolys);
763	}
764
765
766	void BspTree::Construct(const RayContainer &sampleRays,
767	AxisAlignedBox3 *forcedBoundingBox)
768	{
769	// generate new view cells for this contruction type
770	mUsePredefinedViewCells = false;
771
772	mStat.nodes = 1;
773
774	if (forcedBoundingBox)
775	{
776	mBbox = *forcedBoundingBox;
777	}
778	else
779	{
780	mBbox.Initialize(); // initialise BSP tree bounding box
781	}
782
783	PolygonContainer *polys = new PolygonContainer();
784	BoundedRayContainer *rays = new BoundedRayContainer();
785
786	RayContainer::const_iterator rit, rit_end = sampleRays.end();
787
788	long startTime = GetTime();
789	Debug << "** Extracting polygons from rays **\n";
790
791	std::map<Face , Polygon3 > facePolyMap;
792
793	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
794	{
795	//////////////
796	//-- extract polygons intersected by the rays
797	Ray ray = rit;
798
799	// get ray-face intersection. Store polygon representing the rays together
800	// with rays intersecting the face.
801	if (!ray->intersections.empty())
802	{
803	MeshInstance obj = static_cast<MeshInstance >(ray->intersections[0].mObject);
804
805	Mesh *mesh;
806	if (obj->Type() == Intersectable::TRANSFORMED_MESH_INSTANCE)
807	{
808	TransformedMeshInstance *tmobj =
809	static_cast<TransformedMeshInstance *>(obj);
810
811	mesh = new Mesh();
812	tmobj->GetTransformedMesh(*mesh);
813	}
814	else // MeshInstance
815	{
816	mesh = obj->GetMesh();
817	}
818
819	Face *face = mesh->mFaces[ray->intersections[0].mFace];
820	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
821
822	if (it != facePolyMap.end())
823	{
824	//store rays if needed for heuristics
825	if (mSplitPlaneStrategy & BLOCKED_RAYS)
826	(*it).second->mPiercingRays.push_back(ray);
827	}
828	else
829	{
830	//store rays if needed for heuristics
831	Polygon3 *poly = new Polygon3(face, mesh);
832	poly->mParent = obj;
833	polys->push_back(poly);
834
835	if (mSplitPlaneStrategy & BLOCKED_RAYS)
836	poly->mPiercingRays.push_back(ray);
837
838	facePolyMap[face] = poly;
839	}
840
841	// cleanup
842	if (obj->Type() == Intersectable::TRANSFORMED_MESH_INSTANCE)
843	DEL_PTR(mesh);
844	}
845	}
846	// clear helper structure
847	// note: memory will not be released using clear!
848	facePolyMap.clear();
849
850	// compute bounding box
851	if (!forcedBoundingBox)
852	{
853	mBbox.Include(*polys);
854	}
855
856	////////////
857	//-- store rays
858	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
859	{
860	Ray ray = rit;
861	ray->SetId(-1); // reset id
862
863	float minT, maxT;
864	if (mBbox.GetRaySegment(*ray, minT, maxT))
865	rays->push_back(new BoundedRay(ray, minT, maxT));
866	}
867
868	// throw out bad polygons
869	PreprocessPolygons(*polys);
870
871	mStat.polys = (int)polys->size();
872
873	Debug << "** Finished polygon extraction **" << endl;
874	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
875	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
876
877	Construct(polys, rays);
878	}
879
880
881	void BspTree::Construct(const ObjectContainer &objects,
882	const RayContainer &sampleRays,
883	AxisAlignedBox3 *forcedBoundingBox)
884	{
885	// generate new view cells for this construction type
886	mUsePredefinedViewCells = false;
887
888	mStat.nodes = 1;
889	mBbox.Initialize(); // initialise BSP tree bounding box
890
891	if (forcedBoundingBox)
892	{
893	mBbox = *forcedBoundingBox;
894	}
895
896	BoundedRayContainer *rays = new BoundedRayContainer();
897	PolygonContainer *polys = new PolygonContainer();
898
899	// copy mesh instance polygons into one big polygon soup
900	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
901
902	///////
903	//-- store rays
904	RayContainer::const_iterator rit, rit_end = sampleRays.end();
905
906	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
907	{
908	Ray ray = rit;
909	ray->SetId(-1); // reset id
910
911	float minT, maxT;
912	if (mBbox.GetRaySegment(*ray, minT, maxT))
913	rays->push_back(new BoundedRay(ray, minT, maxT));
914	}
915
916	PreprocessPolygons(*polys);
917	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
918	Construct(polys, rays);
919	}
920
921
922	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
923	{
924	BspTraversalStack tStack;
925	mRoot = new BspLeaf();
926
927	// constrruct root node geometry
928	BspNodeGeometry *geom = new BspNodeGeometry();
929	ConstructGeometry(mRoot, *geom);
930
931	BspTraversalData tData(mRoot,
932	polys,
933	0,
934	mOutOfBoundsCell,
935	rays,
936	ComputePvsSize(*rays),
937	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
938	geom);
939
940	mTotalCost = tData.mPvs * tData.mProbability / mBbox.GetVolume();
941	mTotalPvsSize = tData.mPvs;
942
943	mSubdivisionStats
944	<< "#ViewCells\n1\n" << endl
945	<< "#RenderCostDecrease\n0\n" << endl
946	<< "#TotalRenderCost\n" << mTotalCost << endl
947	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
948
949	tStack.push(tData);
950
951	// used for intermediate time measurements and progress
952	long interTime = GetTime();
953	int nleaves = 500;
954
955	mStat.Start();
956	cout << "Constructing bsp tree ...\n";
957	long startTime = GetTime();
958	while (!tStack.empty())
959	{
960	tData = tStack.top();
961	tStack.pop();
962
963	// subdivide leaf node
964	BspNode *r = Subdivide(tStack, tData);
965
966	if (r == mRoot)
967	Debug << "BSP tree construction time spent at root: "
968	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
969
970	if (mStat.Leaves() >= nleaves)
971	{
972	nleaves += 500;
973
974	cout << "leaves=" << mStat.Leaves() << endl;
975	Debug << "needed "
976	<< TimeDiff(interTime, GetTime())*1e-3
977	<< " secs to create 500 leaves" << endl;
978	interTime = GetTime();
979	}
980	}
981
982	cout << "finished\n";
983
984	mStat.Stop();
985	}
986
987
988	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
989	{
990	return
991	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
992	((int)data.mRays->size() <= mTermMinRays) \|\|
993	(data.mPvs <= mTermMinPvs) \|\|
994	(data.mProbability <= mTermMinProbability) \|\|
995	(data.mDepth >= mTermMaxDepth) \|\|
996	(mStat.Leaves() >= mMaxViewCells) \|\|
997	(data.GetAvgRayContribution() > mTermMaxRayContribution));
998	}
999
1000
1001	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
1002	{
1003	////////
1004	//-- terminate traversal
1005
1006	if (TerminationCriteriaMet(tData))
1007	{
1008	BspLeaf leaf = static_cast<BspLeaf >(tData.mNode);
1009
1010	BspViewCell *viewCell;
1011
1012	if (!mUsePredefinedViewCells)
1013	{ // generate new view cell for each leaf
1014	viewCell = new BspViewCell();cout << "g";
1015	}
1016	else
1017	{
1018	// add predefined view cell to leaf
1019	viewCell = static_cast<BspViewCell *>(tData.mViewCell);
1020
1021	// out of bounds cell can be handled as any other view cell,
1022	// responsibility for deleting it has the view cells manager.
1023	if (IsOutOfBounds(viewCell))
1024	{
1025	mOutOfBoundsCellPartOfTree = true;
1026	}
1027
1028	}
1029
1030	leaf->SetViewCell(viewCell);
1031	viewCell->mLeaves.push_back(leaf);
1032
1033	//float probability = max(0.0f, tData.mProbability);
1034	float probability = tData.mProbability;
1035
1036	if (mUseAreaForPvs)
1037	viewCell->SetArea(probability);
1038	else
1039	viewCell->SetVolume(probability);
1040
1041	///////////
1042	//-- add pvs contribution of rays
1043
1044	if (viewCell != mOutOfBoundsCell)
1045	{
1046	int conSamp = 0, sampCon = 0;
1047	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
1048
1049	mStat.contributingSamples += conSamp;
1050	mStat.sampleContributions += sampCon;
1051	}
1052
1053	if (1) EvaluateLeafStats(tData);
1054
1055	////////
1056	//-- clean up
1057
1058	// discard polygons
1059	CLEAR_CONTAINER(*tData.mPolygons);
1060	// discard rays
1061	CLEAR_CONTAINER(*tData.mRays);
1062
1063	delete tData.mPolygons;
1064	delete tData.mRays;
1065	delete tData.mGeometry;
1066
1067	return leaf;
1068	}
1069
1070	///////////
1071	//-- continue subdivision
1072
1073	PolygonContainer coincident;
1074
1075	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1076	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1077	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1078	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1079
1080
1081	// create new interior node and two leaf nodes
1082	BspInterior *interior =
1083	SubdivideNode(tData, tFrontData, tBackData, coincident);
1084
1085	if (1)
1086	{
1087	int pvsData = tData.mPvs;
1088
1089	float cData = (float)pvsData * tData.mProbability;
1090	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1091	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1092
1093	float costDecr = (cFront + cBack - cData) / mBbox.GetVolume();
1094
1095	mTotalCost += costDecr;
1096	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1097
1098	mSubdivisionStats
1099	<< "#ViewCells\n" << mStat.Leaves() << endl
1100	<< "#RenderCostDecrease\n" << -costDecr << endl
1101	<< "#TotalRenderCost\n" << mTotalCost << endl
1102	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1103	}
1104
1105	// extract view cells from coincident polygons
1106	// with respect to the orientation of their normal
1107	// note: if front or back polygons are empty,
1108	// we get the valid in - out classification for the view cell
1109
1110	if (mUsePredefinedViewCells)
1111	{
1112	ExtractViewCells(tFrontData,
1113	tBackData,
1114	coincident,
1115	interior->mPlane);
1116	}
1117
1118	// don't need coincident polygons anymory
1119	CLEAR_CONTAINER(coincident);
1120
1121	// push the children on the stack
1122	tStack.push(tFrontData);
1123	tStack.push(tBackData);
1124
1125	////////
1126	//-- cleanup
1127
1128	DEL_PTR(tData.mNode);
1129	DEL_PTR(tData.mPolygons);
1130	DEL_PTR(tData.mRays);
1131	DEL_PTR(tData.mGeometry);
1132
1133	return interior;
1134	}
1135
1136
1137	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1138	BspTraversalData &backData,
1139	const PolygonContainer &coincident,
1140	const Plane3 &splitPlane) const
1141	{
1142	// if not empty, tree is further subdivided => don't have to find view cell
1143	bool foundFront = !frontData.mPolygons->empty();
1144	bool foundBack = !frontData.mPolygons->empty();
1145
1146	PolygonContainer::const_iterator it =
1147	coincident.begin(), it_end = coincident.end();
1148
1149	//////////
1150	//-- find first view cells in front and back leafs
1151
1152	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1153	{
1154	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1155	{
1156	backData.mViewCell = static_cast<ViewCellLeaf >((it)->mParent);
1157	foundBack = true;
1158	}
1159	else
1160	{
1161	frontData.mViewCell = static_cast<ViewCellLeaf >((it)->mParent);
1162	foundFront = true;
1163	}
1164	}
1165	}
1166
1167
1168	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1169	BspTraversalData &frontData,
1170	BspTraversalData &backData,
1171	PolygonContainer &coincident)
1172	{
1173	mStat.nodes += 2;
1174
1175	BspLeaf leaf = static_cast<BspLeaf >(tData.mNode);
1176
1177	// select subdivision plane
1178	BspInterior *interior = new BspInterior(SelectPlane(leaf, tData));
1179
1180	#ifdef GTP_DEBUG
1181	Debug << interior << endl;
1182	#endif
1183
1184	// subdivide rays into front and back rays
1185	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1186
1187	// subdivide polygons with plane
1188	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1189	*tData.mPolygons,
1190	*frontData.mPolygons,
1191	*backData.mPolygons,
1192	coincident);
1193
1194
1195	// compute pvs
1196	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1197	backData.mPvs = ComputePvsSize(*backData.mRays);
1198
1199	// split geometry and compute area
1200	if (1)
1201	{
1202	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1203	*backData.mGeometry,
1204	interior->mPlane,
1205	mBbox,
1206	//0.000000000001);
1207	mEpsilon);
1208
1209
1210	if (mUseAreaForPvs)
1211	{
1212	frontData.mProbability = frontData.mGeometry->GetArea();
1213	backData.mProbability = backData.mGeometry->GetArea();
1214	}
1215	else
1216	{
1217	frontData.mProbability = frontData.mGeometry->GetVolume();
1218	backData.mProbability = tData.mProbability - frontData.mProbability;
1219	}
1220	}
1221
1222	//-- create front and back leaf
1223
1224	BspInterior *parent = leaf->GetParent();
1225
1226	// replace a link from node's parent
1227	if (!leaf->IsRoot())
1228	{
1229	parent->ReplaceChildLink(leaf, interior);
1230	interior->SetParent(parent);
1231	}
1232	else // new root
1233	{
1234	mRoot = interior;
1235	}
1236
1237	// and setup child links
1238	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1239
1240	frontData.mNode = interior->GetFront();
1241	backData.mNode = interior->GetBack();
1242
1243	interior->mTimeStamp = mTimeStamp ++;
1244
1245	//DEL_PTR(leaf);
1246	return interior;
1247	}
1248
1249
1250	void BspTree::SortSubdivisionCandidates(const PolygonContainer &polys,
1251	const int axis,
1252	vector<SortableEntry> &splitCandidates) const
1253	{
1254	splitCandidates.clear();
1255
1256	int requestedSize = 2 * (int)polys.size();
1257	// creates a sorted split candidates array
1258	splitCandidates.reserve(requestedSize);
1259
1260	PolygonContainer::const_iterator it, it_end = polys.end();
1261
1262	AxisAlignedBox3 box;
1263
1264	// insert all queries
1265	for(it = polys.begin(); it != it_end; ++ it)
1266	{
1267	box.Initialize();
1268	box.Include((it));
1269
1270	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1271	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1272	}
1273
1274	stable_sort(splitCandidates.begin(), splitCandidates.end());
1275	}
1276
1277
1278	float BspTree::BestCostRatio(const PolygonContainer &polys,
1279	const AxisAlignedBox3 &box,
1280	const int axis,
1281	float &position,
1282	int &objectsBack,
1283	int &objectsFront) const
1284	{
1285	vector<SortableEntry> splitCandidates;
1286
1287	SortSubdivisionCandidates(polys, axis, splitCandidates);
1288
1289	// go through the lists, count the number of objects left and right
1290	// and evaluate the following cost funcion:
1291	// C = ct_div_ci + (ol + or)/queries
1292
1293	int objectsLeft = 0, objectsRight = (int)polys.size();
1294
1295	float minBox = box.Min(axis);
1296	float maxBox = box.Max(axis);
1297	float boxArea = box.SurfaceArea();
1298
1299	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1300	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1301
1302	float minSum = 1e20f;
1303	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1304
1305	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1306	{
1307	switch ((*ci).type)
1308	{
1309	case SortableEntry::POLY_MIN:
1310	++ objectsLeft;
1311	break;
1312	case SortableEntry::POLY_MAX:
1313	-- objectsRight;
1314	break;
1315	default:
1316	break;
1317	}
1318
1319	if ((ci).value > minBand && (ci).value < maxBand)
1320	{
1321	AxisAlignedBox3 lbox = box;
1322	AxisAlignedBox3 rbox = box;
1323	lbox.SetMax(axis, (*ci).value);
1324	rbox.SetMin(axis, (*ci).value);
1325
1326	const float sum = objectsLeft * lbox.SurfaceArea() +
1327	objectsRight * rbox.SurfaceArea();
1328
1329	if (sum < minSum)
1330	{
1331	minSum = sum;
1332	position = (*ci).value;
1333
1334	objectsBack = objectsLeft;
1335	objectsFront = objectsRight;
1336	}
1337	}
1338	}
1339
1340	const float oldCost = (float)polys.size();
1341	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1342	const float ratio = newCost / oldCost;
1343
1344	#ifdef GTP_DEBUG
1345	Debug << "====================" << endl;
1346	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1347	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1348	#endif
1349	return ratio;
1350	}
1351
1352	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1353	const PolygonContainer &polys) const
1354	{
1355	AxisAlignedBox3 box;
1356	box.Initialize();
1357
1358	// create bounding box of region
1359	box.Include(polys);
1360
1361	int objectsBack = 0, objectsFront = 0;
1362	int axis = 0;
1363	float costRatio = MAX_FLOAT;
1364	Vector3 position;
1365
1366	//-- area subdivision
1367	for (int i = 0; i < 3; ++ i)
1368	{
1369	float p = 0;
1370	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1371
1372	if (r < costRatio)
1373	{
1374	costRatio = r;
1375	axis = i;
1376	position = p;
1377	}
1378	}
1379
1380	if (costRatio >= mMaxCostRatio)
1381	return false;
1382
1383	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1384	plane = Plane3(norm, position);
1385
1386	return true;
1387	}
1388
1389
1390	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1391	{
1392	if ((!mMaxPolyCandidates \|\| data.mPolygons->empty()) &&
1393	(!mMaxRayCandidates \|\| data.mRays->empty()))
1394	{
1395	Debug << "Warning: No autopartition polygon candidate available\n";
1396
1397	// return axis aligned split
1398	AxisAlignedBox3 box;
1399	box.Initialize();
1400
1401	// create bounding box of region
1402	box.Include(*data.mPolygons);
1403
1404	const int axis = box.Size().DrivingAxis();
1405	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1406
1407	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1408	return Plane3(norm, position);
1409	}
1410
1411	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1412	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1413	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1414	((mTermMinObjectsForAxisAligned < 0) \|\|
1415	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1416	{
1417	Plane3 plane;
1418	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1419	return plane;
1420	}
1421
1422	// simplest strategy: just take next polygon
1423	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1424	{
1425	if (!data.mPolygons->empty())
1426	{
1427	Polygon3 *nextPoly =
1428	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1429	return nextPoly->GetSupportingPlane();
1430	}
1431	else
1432	{
1433	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1434	BoundedRay bRay = (data.mRays)[candidateIdx];
1435
1436	Ray *ray = bRay->mRay;
1437
1438	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1439	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1440
1441	const Vector3 pt = (maxPt + minPt) * 0.5;
1442
1443	const Vector3 normal = ray->GetDir();
1444
1445	return Plane3(normal, pt);
1446	}
1447
1448	return Plane3();
1449	}
1450
1451	// use heuristics to find appropriate plane
1452	return SelectPlaneHeuristics(leaf, data);
1453	}
1454
1455
1456	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1457	{
1458	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1459	BoundedRay *bRay = rays[candidateIdx];
1460	Ray *ray = bRay->mRay;
1461
1462	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1463	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1464
1465	const Vector3 pt = (maxPt + minPt) * 0.5;
1466
1467	const Vector3 normal = ray->GetDir();
1468
1469	return Plane3(normal, pt);
1470	}
1471
1472	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1473	{
1474	Vector3 pt[3];
1475	int idx[3];
1476	int cmaxT = 0;
1477	int cminT = 0;
1478	bool chooseMin = false;
1479
1480	for (int j = 0; j < 3; j ++)
1481	{
1482	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1483
1484	if (idx[j] >= (int)rays.size())
1485	{
1486	idx[j] -= (int)rays.size();
1487	chooseMin = (cminT < 2);
1488	}
1489	else
1490	chooseMin = (cmaxT < 2);
1491
1492	BoundedRay *bRay = rays[idx[j]];
1493	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1494	bRay->mRay->Extrap(bRay->mMaxT);
1495	}
1496
1497	return Plane3(pt[0], pt[1], pt[2]);
1498	}
1499
1500
1501	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1502	{
1503	Vector3 pt[3];
1504
1505	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1506	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1507
1508	// check if rays different
1509	if (idx1 == idx2)
1510	idx2 = (idx2 + 1) % (int)rays.size();
1511
1512	const BoundedRay *ray1 = rays[idx1];
1513	const BoundedRay *ray2 = rays[idx2];
1514
1515	// normal vector of the plane parallel to both lines
1516	const Vector3 norm =
1517	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1518
1519	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1520	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1521
1522	// vector from line 1 to line 2
1523	const Vector3 vd = orig1 - orig2;
1524
1525	// project vector on normal to get distance
1526	const float dist = DotProd(vd, norm);
1527
1528	// point on plane lies halfway between the two planes
1529	const Vector3 planePt = orig1 + norm * dist * 0.5;
1530
1531	return Plane3(norm, planePt);
1532	}
1533
1534
1535	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1536	{
1537	float lowestCost = MAX_FLOAT;
1538	Plane3 bestPlane;
1539	// intermediate plane
1540	Plane3 plane;
1541
1542	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1543	int maxIdx = (int)data.mPolygons->size();
1544
1545	for (int i = 0; i < limit; ++ i)
1546	{
1547	// assure that no index is taken twice
1548	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1549
1550	Polygon3 poly = (data.mPolygons)[candidateIdx];
1551
1552	// swap candidate to the end to avoid testing same plane
1553	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1554	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1555
1556	// evaluate current candidate
1557	const float candidateCost =
1558	SplitPlaneCost(poly->GetSupportingPlane(), data);
1559
1560	if (candidateCost < lowestCost)
1561	{
1562	bestPlane = poly->GetSupportingPlane();
1563	lowestCost = candidateCost;
1564	}
1565	}
1566
1567	//-- choose candidate planes extracted from rays
1568	for (int i = 0; i < mMaxRayCandidates; ++ i)
1569	{
1570	plane = ChooseCandidatePlane3(*data.mRays);
1571	const float candidateCost = SplitPlaneCost(plane, data);
1572
1573	if (candidateCost < lowestCost)
1574	{
1575	bestPlane = plane;
1576	lowestCost = candidateCost;
1577	}
1578	}
1579
1580	#ifdef GTP_DEBUG
1581	Debug << "plane lowest cost: " << lowestCost << endl;
1582	#endif
1583
1584	return bestPlane;
1585	}
1586
1587
1588	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1589	const PolygonContainer &polys) const
1590	{
1591	float val = 0;
1592
1593	float sumBalancedPolys = 0;
1594	float sumSplits = 0;
1595	float sumPolyArea = 0;
1596	float sumBalancedViewCells = 0;
1597	float sumBlockedRays = 0;
1598	float totalBlockedRays = 0;
1599	//float totalArea = 0;
1600	int totalViewCells = 0;
1601
1602	// need three unique ids for each type of view cell
1603	// for balanced view cells criterium
1604	ViewCell::NewMail();
1605	const int backId = ViewCell::sMailId;
1606	ViewCell::NewMail();
1607	const int frontId = ViewCell::sMailId;
1608	ViewCell::NewMail();
1609	const int frontAndBackId = ViewCell::sMailId;
1610
1611	bool useRand;
1612	int limit;
1613
1614	// choose test polyongs randomly if over threshold
1615	if ((int)polys.size() > mMaxTests)
1616	{
1617	useRand = true;
1618	limit = mMaxTests;
1619	}
1620	else
1621	{
1622	useRand = false;
1623	limit = (int)polys.size();
1624	}
1625
1626	for (int i = 0; i < limit; ++ i)
1627	{
1628	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1629
1630	Polygon3 *poly = polys[testIdx];
1631
1632	const int classification =
1633	poly->ClassifyPlane(candidatePlane, mEpsilon);
1634
1635	if (mSplitPlaneStrategy & BALANCED_POLYS)
1636	sumBalancedPolys += sBalancedPolysTable[classification];
1637
1638	if (mSplitPlaneStrategy & LEAST_SPLITS)
1639	sumSplits += sLeastPolySplitsTable[classification];
1640
1641	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1642	{
1643	if (classification == Polygon3::COINCIDENT)
1644	sumPolyArea += poly->GetArea();
1645	//totalArea += area;
1646	}
1647
1648	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1649	{
1650	const float blockedRays = (float)poly->mPiercingRays.size();
1651
1652	if (classification == Polygon3::COINCIDENT)
1653	sumBlockedRays += blockedRays;
1654
1655	totalBlockedRays += blockedRays;
1656	}
1657
1658	// assign view cells to back or front according to classificaion
1659	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1660	{
1661	MeshInstance *viewCell = poly->mParent;
1662
1663	// assure that we only count a view cell
1664	// once for the front and once for the back side of the plane
1665	if (classification == Polygon3::FRONT_SIDE)
1666	{
1667	if ((viewCell->mMailbox != frontId) &&
1668	(viewCell->mMailbox != frontAndBackId))
1669	{
1670	sumBalancedViewCells += 1.0;
1671
1672	if (viewCell->mMailbox != backId)
1673	viewCell->mMailbox = frontId;
1674	else
1675	viewCell->mMailbox = frontAndBackId;
1676
1677	++ totalViewCells;
1678	}
1679	}
1680	else if (classification == Polygon3::BACK_SIDE)
1681	{
1682	if ((viewCell->mMailbox != backId) &&
1683	(viewCell->mMailbox != frontAndBackId))
1684	{
1685	sumBalancedViewCells -= 1.0;
1686
1687	if (viewCell->mMailbox != frontId)
1688	viewCell->mMailbox = backId;
1689	else
1690	viewCell->mMailbox = frontAndBackId;
1691
1692	++ totalViewCells;
1693	}
1694	}
1695	}
1696	}
1697
1698	const float polysSize = (float)polys.size() + Limits::Small;
1699
1700	// all values should be approx. between 0 and 1 so they can be combined
1701	// and scaled with the factors according to their importance
1702	if (mSplitPlaneStrategy & BALANCED_POLYS)
1703	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1704
1705	if (mSplitPlaneStrategy & LEAST_SPLITS)
1706	val += mLeastSplitsFactor * sumSplits / polysSize;
1707
1708	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1709	// HACK: polys.size should be total area so scaling is between 0 and 1
1710	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1711
1712	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1713	if (totalBlockedRays != 0)
1714	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1715
1716	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1717	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1718	((float)totalViewCells + Limits::Small);
1719
1720	return val;
1721	}
1722
1723
1724	inline void BspTree::GenerateUniqueIdsForPvs()
1725	{
1726	Intersectable::NewMail(); sBackId = Intersectable::sMailId;
1727	Intersectable::NewMail(); sFrontId = Intersectable::sMailId;
1728	Intersectable::NewMail(); sFrontAndBackId = Intersectable::sMailId;
1729	}
1730
1731
1732	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1733	const BoundedRayContainer &rays,
1734	const int pvs,
1735	const float probability,
1736	const BspNodeGeometry &cell) const
1737	{
1738	float val = 0;
1739
1740	float sumBalancedRays = 0;
1741	float sumRaySplits = 0;
1742
1743	int frontPvs = 0;
1744	int backPvs = 0;
1745
1746	// probability that view point lies in child
1747	float pOverall = 0;
1748	float pFront = 0;
1749	float pBack = 0;
1750
1751	const bool pvsUseLen = false;
1752
1753
1754	if (mSplitPlaneStrategy & PVS)
1755	{
1756	// create unique ids for pvs heuristics
1757	GenerateUniqueIdsForPvs();
1758
1759	// construct child geometry with regard to the candidate split plane
1760	BspNodeGeometry geomFront;
1761	BspNodeGeometry geomBack;
1762
1763	const bool splitSuccessFull =
1764	cell.SplitGeometry(geomFront,
1765	geomBack,
1766	candidatePlane,
1767	mBbox,
1768	mEpsilon);
1769
1770	if (mUseAreaForPvs)
1771	{
1772	pFront = geomFront.GetArea();
1773	pBack = geomBack.GetArea();
1774	}
1775	else
1776	{
1777	pFront = geomFront.GetVolume();
1778	pBack = pOverall - pFront;
1779	}
1780
1781
1782	// give penalty to unbalanced split
1783	if (1 &&
1784	(!splitSuccessFull \|\| (pFront <= 0) \|\| (pBack <= 0) \|\|
1785	!geomFront.Valid() \|\| !geomBack.Valid()))
1786	{
1787	//Debug << "error f: " << pFront << " b: " << pBack << endl;
1788	return 99999.9f;
1789	}
1790
1791	pOverall = probability;
1792	}
1793
1794	bool useRand;
1795	int limit;
1796
1797	// choose test polyongs randomly if over threshold
1798	if ((int)rays.size() > mMaxTests)
1799	{
1800	useRand = true;
1801	limit = mMaxTests;
1802	}
1803	else
1804	{
1805	useRand = false;
1806	limit = (int)rays.size();
1807	}
1808
1809	for (int i = 0; i < limit; ++ i)
1810	{
1811	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1812
1813	BoundedRay *bRay = rays[testIdx];
1814
1815	Ray *ray = bRay->mRay;
1816	const float minT = bRay->mMinT;
1817	const float maxT = bRay->mMaxT;
1818
1819	Vector3 entP, extP;
1820
1821	const int cf =
1822	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1823
1824	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1825	{
1826	sumBalancedRays += sBalancedRaysTable[cf];
1827	}
1828
1829	if (mSplitPlaneStrategy & BALANCED_RAYS)
1830	{
1831	sumRaySplits += sLeastRaySplitsTable[cf];
1832	}
1833
1834	if (mSplitPlaneStrategy & PVS)
1835	{
1836	// in case the ray intersects an object
1837	// assure that we only count the object
1838	// once for the front and once for the back side of the plane
1839
1840	// add the termination object
1841	if (!ray->intersections.empty())
1842	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1843
1844	// add the source object
1845	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1846	}
1847	}
1848
1849	const float raysSize = (float)rays.size() + Limits::Small;
1850
1851	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1852	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1853
1854	if (mSplitPlaneStrategy & BALANCED_RAYS)
1855	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1856
1857	const float denom = pOverall * (float)pvs + Limits::Small;
1858
1859	if (mSplitPlaneStrategy & PVS)
1860	{
1861	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1862	}
1863
1864
1865	#ifdef GTP_DEBUG
1866	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1867	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1868	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1869	#endif
1870
1871	return val;
1872	}
1873
1874	void BspTree::AddObjToPvs(Intersectable *obj,
1875	const int cf,
1876	int &frontPvs,
1877	int &backPvs) const
1878	{
1879	if (!obj)
1880	return;
1881	// TODO: does this really belong to no pvs?
1882	//if (cf == Ray::COINCIDENT) return;
1883
1884	// object belongs to both PVS
1885	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1886	(cf == Ray::BACK_FRONT) \|\|
1887	(cf == Ray::COINCIDENT);
1888
1889	if ((cf == Ray::FRONT) \|\| bothSides)
1890	{
1891	if ((obj->mMailbox != sFrontId) &&
1892	(obj->mMailbox != sFrontAndBackId))
1893	{
1894	++ frontPvs;
1895
1896	if (obj->mMailbox == sBackId)
1897	obj->mMailbox = sFrontAndBackId;
1898	else
1899	obj->mMailbox = sFrontId;
1900	}
1901	}
1902
1903	if ((cf == Ray::BACK) \|\| bothSides)
1904	{
1905	if ((obj->mMailbox != sBackId) &&
1906	(obj->mMailbox != sFrontAndBackId))
1907	{
1908	++ backPvs;
1909
1910	if (obj->mMailbox == sFrontId)
1911	obj->mMailbox = sFrontAndBackId;
1912	else
1913	obj->mMailbox = sBackId;
1914	}
1915	}
1916	}
1917
1918
1919	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1920	BspTraversalData &data) const
1921	{
1922	float val = 0;
1923
1924	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1925	{
1926	Vector3 tinyAxis(0,0,0); tinyAxis[mBbox.Size().TinyAxis()] = 1.0f;
1927	// we put a penalty on the dot product between the "tiny" vertical axis
1928	// and the split plane axis
1929	val += mVerticalSplitsFactor *
1930	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1931	}
1932
1933	// the following criteria loop over all polygons to find the cost value
1934	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1935	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1936	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1937	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1938	(mSplitPlaneStrategy & BLOCKED_RAYS))
1939	{
1940	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1941	}
1942
1943	// the following criteria loop over all rays to find the cost value
1944	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1945	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1946	(mSplitPlaneStrategy & PVS))
1947	{
1948	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1949	data.mProbability, *data.mGeometry);
1950	}
1951
1952	// return linear combination of the sums
1953	return val;
1954	}
1955
1956	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1957	{
1958	stack<BspNode *> nodeStack;
1959	nodeStack.push(mRoot);
1960
1961	while (!nodeStack.empty())
1962	{
1963	BspNode *node = nodeStack.top();
1964
1965	nodeStack.pop();
1966
1967	if (node->IsLeaf())
1968	{
1969	BspLeaf leaf = (BspLeaf )node;
1970	leaves.push_back(leaf);
1971	}
1972	else
1973	{
1974	BspInterior interior = static_cast<BspInterior >(node);
1975
1976	nodeStack.push(interior->GetBack());
1977	nodeStack.push(interior->GetFront());
1978	}
1979	}
1980	}
1981
1982
1983	AxisAlignedBox3 BspTree::GetBoundingBox() const
1984	{
1985	return mBbox;
1986	}
1987
1988
1989	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1990	{
1991	// the node became a leaf -> evaluate stats for leafs
1992	BspLeaf leaf = static_cast<BspLeaf >(data.mNode);
1993
1994	// store maximal and minimal depth
1995	if (data.mDepth > mStat.maxDepth)
1996	mStat.maxDepth = data.mDepth;
1997
1998	if (data.mDepth < mStat.minDepth)
1999	mStat.minDepth = data.mDepth;
2000
2001	// accumulate depth to compute average depth
2002	mStat.accumDepth += data.mDepth;
2003	// accumulate rays to compute rays / leaf
2004	mStat.accumRays += (int)data.mRays->size();
2005
2006	if (data.mDepth >= mTermMaxDepth)
2007	++ mStat.maxDepthNodes;
2008
2009	if (data.mPvs < mTermMinPvs)
2010	++ mStat.minPvsNodes;
2011
2012	if ((int)data.mRays->size() < mTermMinRays)
2013	++ mStat.minRaysNodes;
2014
2015	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
2016	++ mStat.maxRayContribNodes;
2017
2018	if (data.mProbability <= mTermMinProbability)
2019	++ mStat.minProbabilityNodes;
2020
2021	#ifdef GTP_DEBUG
2022	Debug << "BSP stats: "
2023	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
2024	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
2025	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
2026	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
2027	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
2028	<< "#pvs: " << leaf->GetViewCell()->GetPvs().EvalPvsCost() << "=, "
2029	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
2030	#endif
2031	}
2032
2033
2034	int BspTree::_CastRay(Ray &ray)
2035	{
2036	int hits = 0;
2037
2038	stack<BspRayTraversalData> tStack;
2039
2040	float maxt, mint;
2041
2042	if (!mBbox.GetRaySegment(ray, mint, maxt))
2043	return 0;
2044
2045	ViewCell::NewMail();
2046
2047	Vector3 entp = ray.Extrap(mint);
2048	Vector3 extp = ray.Extrap(maxt);
2049
2050	BspNode *node = mRoot;
2051	BspNode *farChild = NULL;
2052
2053	while (1)
2054	{
2055	if (!node->IsLeaf())
2056	{
2057	BspInterior in = static_cast<BspInterior >(node);
2058
2059	Plane3 splitPlane = in->GetPlane();
2060	const int entSide = splitPlane.Side(entp);
2061	const int extSide = splitPlane.Side(extp);
2062
2063	if (entSide < 0)
2064	{
2065	node = in->GetBack();
2066
2067	if(extSide <= 0) // plane does not split ray => no far child
2068	continue;
2069
2070	farChild = in->GetFront(); // plane splits ray
2071
2072	} else if (entSide > 0)
2073	{
2074	node = in->GetFront();
2075
2076	if (extSide >= 0) // plane does not split ray => no far child
2077	continue;
2078
2079	farChild = in->GetBack(); // plane splits ray
2080	}
2081	else // ray and plane are coincident
2082	{
2083	// WHAT TO DO IN THIS CASE ?
2084	//break;
2085	node = in->GetFront();
2086	continue;
2087	}
2088
2089	// push data for far child
2090	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2091
2092	// find intersection of ray segment with plane
2093	float t;
2094	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
2095	maxt *= t;
2096
2097	} else // reached leaf => intersection with view cell
2098	{
2099	BspLeaf leaf = static_cast<BspLeaf >(node);
2100
2101	if (!leaf->mViewCell->Mailed())
2102	{
2103	//ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
2104	leaf->mViewCell->Mail();
2105	++ hits;
2106	}
2107
2108	//-- fetch the next far child from the stack
2109	if (tStack.empty())
2110	break;
2111
2112	entp = extp;
2113	mint = maxt; // NOTE: need this?
2114
2115	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
2116	break;
2117
2118	BspRayTraversalData &s = tStack.top();
2119
2120	node = s.mNode;
2121	extp = s.mExitPoint;
2122	maxt = s.mMaxT;
2123
2124	tStack.pop();
2125	}
2126	}
2127
2128	return hits;
2129	}
2130
2131
2132	int BspTree::CastLineSegment(const Vector3 &origin,
2133	const Vector3 &termination,
2134	ViewCellContainer &viewcells)
2135	{
2136	int hits = 0;
2137	stack<BspRayTraversalData> tStack;
2138
2139	float mint = 0.0f, maxt = 1.0f;
2140
2141	//ViewCell::NewMail();
2142
2143	Vector3 entp = origin;
2144	Vector3 extp = termination;
2145
2146	BspNode *node = mRoot;
2147	BspNode *farChild = NULL;
2148
2149
2150	const float thresh = 1 ? 1e-6f : 0.0f;
2151
2152	while (1)
2153	{
2154	if (!node->IsLeaf())
2155	{
2156	BspInterior in = static_cast<BspInterior >(node);
2157
2158	Plane3 splitPlane = in->GetPlane();
2159
2160	const int entSide = splitPlane.Side(entp, thresh);
2161	const int extSide = splitPlane.Side(extp, thresh);
2162
2163	if (entSide < 0)
2164	{
2165	node = in->GetBack();
2166
2167	// plane does not split ray => no far child
2168	if (extSide <= 0)
2169	continue;
2170
2171	farChild = in->GetFront(); // plane splits ray
2172	}
2173	else if (entSide > 0)
2174	{
2175	node = in->GetFront();
2176
2177	if (extSide >= 0) // plane does not split ray => no far child
2178	continue;
2179
2180	farChild = in->GetBack(); // plane splits ray
2181	}
2182	else // one of the ray end points is on the plane
2183	{ // NOTE: what to do if ray is coincident with plane?
2184	if (extSide < 0)
2185	node = in->GetBack();
2186	else //if (extSide > 0)
2187	node = in->GetFront();
2188	//else break; // coincident => count no intersections
2189
2190	continue; // no far child
2191	}
2192
2193	// push data for far child
2194	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2195
2196	// find intersection of ray segment with plane
2197	float t;
2198	extp = splitPlane.FindIntersection(origin, extp, &t);
2199	maxt *= t;
2200	}
2201	else
2202	{
2203	// reached leaf => intersection with view cell
2204	BspLeaf leaf = static_cast<BspLeaf >(node);
2205
2206	if (!leaf->mViewCell->Mailed())
2207	{
2208	viewcells.push_back(leaf->mViewCell);
2209	leaf->mViewCell->Mail();
2210	++ hits;
2211	}
2212
2213	//-- fetch the next far child from the stack
2214	if (tStack.empty())
2215	break;
2216
2217	entp = extp;
2218	mint = maxt; // NOTE: need this?
2219
2220	BspRayTraversalData &s = tStack.top();
2221
2222	node = s.mNode;
2223	extp = s.mExitPoint;
2224	maxt = s.mMaxT;
2225
2226	tStack.pop();
2227	}
2228	}
2229
2230	return hits;
2231	}
2232
2233
2234	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2235	{
2236	stack<BspNode *> nodeStack;
2237	nodeStack.push(mRoot);
2238
2239	ViewCell::NewMail();
2240
2241	while (!nodeStack.empty())
2242	{
2243	BspNode *node = nodeStack.top();
2244	nodeStack.pop();
2245
2246	if (node->IsLeaf())
2247	{
2248	ViewCellLeaf viewCell = static_cast<BspLeaf >(node)->mViewCell;
2249
2250	if (!viewCell->Mailed())
2251	{
2252	viewCell->Mail();
2253	viewCells.push_back(viewCell);
2254	}
2255	}
2256	else
2257	{
2258	BspInterior interior = static_cast<BspInterior >(node);
2259
2260	nodeStack.push(interior->GetFront());
2261	nodeStack.push(interior->GetBack());
2262	}
2263	}
2264	}
2265
2266
2267	BspTreeStatistics &BspTree::GetStat()
2268	{
2269	return mStat;
2270	}
2271
2272
2273	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2274	{
2275	float len = 0;
2276
2277	BoundedRayContainer::const_iterator it, it_end = rays.end();
2278
2279	for (it = rays.begin(); it != it_end; ++ it)
2280	{
2281	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2282	(it)->mRay->Extrap((it)->mMaxT));
2283	}
2284
2285	return len;
2286	}
2287
2288
2289	int BspTree::SplitRays(const Plane3 &plane,
2290	BoundedRayContainer &rays,
2291	BoundedRayContainer &frontRays,
2292	BoundedRayContainer &backRays)
2293	{
2294	int splits = 0;
2295
2296	while (!rays.empty())
2297	{
2298	BoundedRay *bRay = rays.back();
2299	Ray *ray = bRay->mRay;
2300	float minT = bRay->mMinT;
2301	float maxT = bRay->mMaxT;
2302
2303	rays.pop_back();
2304
2305	Vector3 entP, extP;
2306
2307	const int cf =
2308	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2309
2310	// set id to ray classification
2311	ray->SetId(cf);
2312
2313	switch (cf)
2314	{
2315	case Ray::COINCIDENT: // TODO: should really discard ray?
2316	frontRays.push_back(bRay);
2317	break;
2318	case Ray::BACK:
2319	backRays.push_back(bRay);
2320	break;
2321	case Ray::FRONT:
2322	frontRays.push_back(bRay);
2323	break;
2324	case Ray::FRONT_BACK:
2325	{
2326	// find intersection of ray segment with plane
2327	const float t = plane.FindT(ray->GetLoc(), extP);
2328
2329	const float newT = t * maxT;
2330
2331	frontRays.push_back(new BoundedRay(ray, minT, newT));
2332	backRays.push_back(new BoundedRay(ray, newT, maxT));
2333
2334	DEL_PTR(bRay);
2335	}
2336	break;
2337	case Ray::BACK_FRONT:
2338	{
2339	// find intersection of ray segment with plane
2340	const float t = plane.FindT(ray->GetLoc(), extP);
2341	const float newT = t * bRay->mMaxT;
2342
2343	backRays.push_back(new BoundedRay(ray, minT, newT));
2344	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2345
2346	DEL_PTR(bRay);
2347
2348	++ splits;
2349	}
2350	break;
2351	default:
2352	Debug << "Should not come here 4" << endl;
2353	break;
2354	}
2355	}
2356
2357	return splits;
2358	}
2359
2360	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2361	{
2362	BspNode *lastNode;
2363
2364	do
2365	{
2366	lastNode = n;
2367
2368	// want to get planes defining geometry of this node => don't take
2369	// split plane of node itself
2370	n = n->GetParent();
2371
2372	if (n)
2373	{
2374	BspInterior interior = static_cast<BspInterior >(n);
2375	Plane3 halfSpace = static_cast<BspInterior *>(interior)->GetPlane();
2376
2377	if (interior->GetBack() != lastNode)
2378	halfSpace.ReverseOrientation();
2379
2380	halfSpaces.push_back(halfSpace);
2381	}
2382	}
2383	while (n);
2384	}
2385
2386
2387	void BspTree::ConstructGeometry(ViewCell *vc,
2388	BspNodeGeometry &vcGeom) const
2389	{
2390	// if false, cannot construct geometry for interior leaf
2391	if (!mViewCellsTree)
2392	return;
2393
2394	ViewCellContainer leaves;
2395	mViewCellsTree->CollectLeaves(vc, leaves);
2396
2397	ViewCellContainer::const_iterator it, it_end = leaves.end();
2398
2399	for (it = leaves.begin(); it != it_end; ++ it)
2400	{
2401	// per definition out of bounds cell has zero volume
2402	if (IsOutOfBounds(*it))
2403	continue;
2404
2405	BspViewCell bspVc = static_cast<BspViewCell >(*it);
2406	vector<BspLeaf *>::const_iterator bit, bit_end = bspVc->mLeaves.end();
2407
2408	for (bit = bspVc->mLeaves.begin(); bit != bit_end; ++ bit)
2409	{
2410	BspLeaf l = bit;
2411	ConstructGeometry(l, vcGeom);
2412	}
2413	}
2414	}
2415
2416
2417	void BspTree::ConstructGeometry(BspNode *n,
2418	BspNodeGeometry &geom) const
2419	{
2420	vector<Plane3> halfSpaces;
2421	ExtractHalfSpaces(n, halfSpaces);
2422
2423	PolygonContainer candidatePolys;
2424	vector<Plane3> candidatePlanes;
2425
2426	vector<Plane3>::const_iterator pit, pit_end = halfSpaces.end();
2427
2428	// bounded planes are added to the polygons
2429	for (pit = halfSpaces.begin(); pit != pit_end; ++ pit)
2430	{
2431	Polygon3 p = GetBoundingBox().CrossSection(pit);
2432
2433	if (p->Valid(mEpsilon))
2434	{
2435	candidatePolys.push_back(p);
2436	candidatePlanes.push_back(*pit);
2437	}
2438	}
2439
2440	// add faces of bounding box (also could be faces of the cell)
2441	for (int i = 0; i < 6; ++ i)
2442	{
2443	VertexContainer vertices;
2444
2445	for (int j = 0; j < 4; ++ j)
2446	vertices.push_back(mBbox.GetFace(i).mVertices[j]);
2447
2448	Polygon3 *poly = new Polygon3(vertices);
2449
2450	candidatePolys.push_back(poly);
2451	candidatePlanes.push_back(poly->GetSupportingPlane());
2452	}
2453
2454	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2455	{
2456	// polygon is split by all other planes
2457	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2458	{
2459	if (i == j) // polygon and plane are coincident
2460	continue;
2461
2462	VertexContainer splitPts;
2463	Polygon3 frontPoly, backPoly;
2464
2465	const int cf =
2466	candidatePolys[i]->ClassifyPlane(halfSpaces[j],
2467	mEpsilon);
2468
2469	switch (cf)
2470	{
2471	case Polygon3::SPLIT:
2472	frontPoly = new Polygon3();
2473	backPoly = new Polygon3();
2474
2475	candidatePolys[i]->Split(halfSpaces[j],
2476	*frontPoly,
2477	*backPoly,
2478	mEpsilon);
2479
2480	DEL_PTR(candidatePolys[i]);
2481
2482	if (backPoly->Valid(mEpsilon))
2483	candidatePolys[i] = backPoly;
2484	else
2485	DEL_PTR(backPoly);
2486
2487	// outside, don't need this
2488	DEL_PTR(frontPoly);
2489	break;
2490	// polygon outside of halfspace
2491	case Polygon3::FRONT_SIDE:
2492	DEL_PTR(candidatePolys[i]);
2493	break;
2494	// just take polygon as it is
2495	case Polygon3::BACK_SIDE:
2496	case Polygon3::COINCIDENT:
2497	default:
2498	break;
2499	}
2500	}
2501
2502	if (candidatePolys[i])
2503	{
2504	geom.Add(candidatePolys[i], candidatePlanes[i]);
2505	}
2506	}
2507	}
2508
2509
2510	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2511	{
2512	mViewCellsManager = vcm;
2513	}
2514
2515
2516	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2517
2518
2519	int BspTree::FindNeighbors(BspNode *n,
2520	vector<BspLeaf *> &neighbors,
2521	const bool onlyUnmailed) const
2522	{
2523	stack<bspNodePair> nodeStack;
2524
2525	BspNodeGeometry nodeGeom;
2526	ConstructGeometry(n, nodeGeom);
2527
2528	// split planes from the root to this node
2529	// needed to verify that we found neighbor leaf
2530	// TODO: really needed?
2531	vector<Plane3> halfSpaces;
2532	ExtractHalfSpaces(n, halfSpaces);
2533
2534
2535	BspNodeGeometry *rgeom = new BspNodeGeometry();
2536	ConstructGeometry(mRoot, *rgeom);
2537
2538	nodeStack.push(bspNodePair(mRoot, rgeom));
2539
2540	while (!nodeStack.empty())
2541	{
2542	BspNode *node = nodeStack.top().first;
2543	BspNodeGeometry *geom = nodeStack.top().second;
2544
2545	nodeStack.pop();
2546
2547	if (node->IsLeaf())
2548	{
2549	// test if this leaf is in valid view space
2550	if (node->TreeValid() &&
2551	(node != n) &&
2552	(!onlyUnmailed \|\| !node->Mailed()))
2553	{
2554	bool isAdjacent = true;
2555
2556	if (1)
2557	{
2558	// test all planes of current node if still adjacent
2559	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2560	{
2561	const int cf =
2562	Polygon3::ClassifyPlane(geom->GetPolys(),
2563	halfSpaces[i],
2564	mEpsilon);
2565
2566	if (cf == Polygon3::FRONT_SIDE)
2567	{
2568	isAdjacent = false;
2569	}
2570	}
2571	}
2572	else
2573	{
2574	// TODO: why is this wrong??
2575	// test all planes of current node if still adjacent
2576	for (int i = 0; (i < nodeGeom.Size()) && isAdjacent; ++ i)
2577	{
2578	Polygon3 *poly = nodeGeom.GetPolys()[i];
2579
2580	const int cf =
2581	Polygon3::ClassifyPlane(geom->GetPolys(),
2582	poly->GetSupportingPlane(),
2583	mEpsilon);
2584
2585	if (cf == Polygon3::FRONT_SIDE)
2586	{
2587	isAdjacent = false;
2588	}
2589	}
2590	}
2591	// neighbor was found
2592	if (isAdjacent)
2593	{
2594	neighbors.push_back(static_cast<BspLeaf *>(node));
2595	}
2596	}
2597	}
2598	else
2599	{
2600	BspInterior interior = static_cast<BspInterior >(node);
2601
2602	const int cf = Polygon3::ClassifyPlane(nodeGeom.GetPolys(),
2603	interior->GetPlane(),
2604	mEpsilon);
2605
2606	BspNode *front = interior->GetFront();
2607	BspNode *back = interior->GetBack();
2608
2609	BspNodeGeometry *fGeom = new BspNodeGeometry();
2610	BspNodeGeometry *bGeom = new BspNodeGeometry();
2611
2612	geom->SplitGeometry(*fGeom,
2613	*bGeom,
2614	interior->GetPlane(),
2615	mBbox,
2616	//0.0000001f);
2617	mEpsilon);
2618
2619	if (cf == Polygon3::BACK_SIDE)
2620	{
2621	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2622	DEL_PTR(fGeom);
2623	}
2624	else
2625	{
2626	if (cf == Polygon3::FRONT_SIDE)
2627	{
2628	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2629	DEL_PTR(bGeom);
2630	}
2631	else
2632	{ // random decision
2633	nodeStack.push(bspNodePair(front, fGeom));
2634	nodeStack.push(bspNodePair(back, bGeom));
2635	}
2636	}
2637	}
2638
2639	DEL_PTR(geom);
2640	}
2641
2642	return (int)neighbors.size();
2643	}
2644
2645
2646	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2647	{
2648	stack<BspNode *> nodeStack;
2649
2650	nodeStack.push(mRoot);
2651
2652	int mask = rand();
2653
2654	while (!nodeStack.empty())
2655	{
2656	BspNode *node = nodeStack.top();
2657	nodeStack.pop();
2658
2659	if (node->IsLeaf())
2660	{
2661	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2662	return static_cast<BspLeaf *>(node);
2663	}
2664	else
2665	{
2666	BspInterior interior = static_cast<BspInterior >(node);
2667
2668	// random decision
2669	if (mask & 1)
2670	nodeStack.push(interior->GetBack());
2671	else
2672	nodeStack.push(interior->GetFront());
2673
2674	mask = mask >> 1;
2675	}
2676	}
2677
2678	return NULL;
2679	}
2680
2681
2682	void BspTree::AddToPvs(BspLeaf *leaf,
2683	const BoundedRayContainer &rays,
2684	int &sampleContributions,
2685	int &contributingSamples)
2686	{
2687	sampleContributions = 0;
2688	contributingSamples = 0;
2689
2690	BoundedRayContainer::const_iterator it, it_end = rays.end();
2691
2692	ViewCellLeaf *vc = leaf->GetViewCell();
2693
2694	// add contributions from samples to the PVS
2695	for (it = rays.begin(); it != it_end; ++ it)
2696	{
2697	float contribution = 0;
2698	Ray ray = (it)->mRay;
2699	//float relContribution;
2700	if (!ray->intersections.empty())
2701	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2702	1.0f);
2703	//relContribution);
2704
2705	if (ray->sourceObject.mObject)
2706	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2707	1.0f);
2708	//relContribution);
2709
2710	if (contribution > 0)
2711	{
2712	sampleContributions += (int)contribution;
2713	++ contributingSamples;
2714	}
2715
2716	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2717	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2718	}
2719	}
2720
2721
2722	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2723	{
2724	int pvsSize = 0;
2725
2726	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2727
2728	Intersectable::NewMail();
2729
2730	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2731	{
2732	Ray ray = (rit)->mRay;
2733
2734	if (!ray->intersections.empty())
2735	{
2736	if (!ray->intersections[0].mObject->Mailed())
2737	{
2738	ray->intersections[0].mObject->Mail();
2739	++ pvsSize;
2740	}
2741	}
2742	if (ray->sourceObject.mObject)
2743	{
2744	if (!ray->sourceObject.mObject->Mailed())
2745	{
2746	ray->sourceObject.mObject->Mail();
2747	++ pvsSize;
2748	}
2749	}
2750	}
2751
2752	return pvsSize;
2753	}
2754
2755
2756	float BspTree::GetEpsilon() const
2757	{
2758	return mEpsilon;
2759	}
2760
2761
2762	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2763	vector<MergeCandidate> &candidates)
2764	{
2765	BspLeaf::NewMail();
2766
2767	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2768
2769	int numCandidates = 0;
2770
2771	// find merge candidates and push them into queue
2772	for (it = leaves.begin(); it != it_end; ++ it)
2773	{
2774	BspLeaf leaf = it;
2775
2776	// the same leaves must not be part of two merge candidates
2777	leaf->Mail();
2778	vector<BspLeaf *> neighbors;
2779	FindNeighbors(leaf, neighbors, true);
2780
2781	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2782
2783	// TODO: test if at least one ray goes from one leaf to the other
2784	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2785	{
2786	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2787	{
2788	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2789	candidates.push_back(mc);
2790
2791	++ numCandidates;
2792	if ((numCandidates % 1000) == 0)
2793	{
2794	cout << "collected " << numCandidates << " merge candidates" << endl;
2795	}
2796	}
2797	}
2798	}
2799
2800	Debug << "merge queue: " << (int)candidates.size() << endl;
2801	Debug << "leaves in queue: " << numCandidates << endl;
2802
2803
2804	return (int)leaves.size();
2805	}
2806
2807
2808	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2809	vector<MergeCandidate> &candidates)
2810	{
2811	ViewCell::NewMail();
2812	long startTime = GetTime();
2813
2814	map<BspLeaf , vector<BspLeaf> > neighborMap;
2815	ViewCellContainer::const_iterator iit;
2816
2817	int numLeaves = 0;
2818
2819	BspLeaf::NewMail();
2820
2821	for (int i = 0; i < (int)rays.size(); ++ i)
2822	{
2823	VssRay *ray = rays[i];
2824	#if VSS_STORE_VIEWCELLS
2825
2826	// traverse leaves stored in the rays and compare and
2827	// merge consecutive leaves (i.e., the neighbors in the tree)
2828	if (ray->mViewCells.size() < 2)
2829	continue;
2830
2831	iit = ray->mViewCells.begin();
2832	BspViewCell bspVc = static_cast<BspViewCell >(*(iit ++));
2833	BspLeaf *leaf = bspVc->mLeaves[0];
2834
2835	// traverse intersections
2836	// consecutive leaves are neighbors => add them to queue
2837	for (; iit != ray->mViewCells.end(); ++ iit)
2838	{
2839	// next pair
2840	BspLeaf *prevLeaf = leaf;
2841	bspVc = static_cast<BspViewCell >(iit);
2842	leaf = bspVc->mLeaves[0];
2843
2844	// view space not valid or same view cell
2845	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2846	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2847	continue;
2848
2849	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2850
2851	bool found = false;
2852
2853	// both leaves inserted in queue already =>
2854	// look if double pair already exists
2855	if (leaf->Mailed() && prevLeaf->Mailed())
2856	{
2857	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2858
2859	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2860	if (*it == prevLeaf)
2861	found = true; // already in queue
2862	}
2863
2864	if (!found)
2865	{
2866	// this pair is not in map yet
2867	// => insert into the neighbor map and the queue
2868	neighbors.push_back(prevLeaf);
2869	neighborMap[prevLeaf].push_back(leaf);
2870
2871	leaf->Mail();
2872	prevLeaf->Mail();
2873
2874	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2875
2876	candidates.push_back(mc);
2877
2878	if ((candidates.size() % 1000) == 0)
2879	{
2880	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2881	}
2882	}
2883	}
2884	#endif
2885	}
2886
2887	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2888	Debug << "merge queue: " << (int)candidates.size() << endl;
2889	Debug << "leaves in queue: " << numLeaves << endl;
2890
2891	#if 0
2892	//////////
2893	//-- collect the leaves which haven't been found by ray casting
2894	cout << "finding additional merge candidates using geometry" << endl;
2895	vector<BspLeaf *> leaves;
2896	CollectLeaves(leaves, true);
2897	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2898	CollectMergeCandidates(leaves, candidates);
2899	#endif
2900
2901	return numLeaves;
2902	}
2903
2904
2905
2906	/***************************************************************/
2907	/* BspNodeGeometry Implementation */
2908	/***************************************************************/
2909
2910
2911	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2912	{
2913	mPolys.reserve(rhs.mPolys.size());
2914	mPlanes.reserve(rhs.mPolys.size());
2915
2916	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2917
2918	int i = 0;
2919
2920	for (it = rhs.mPolys.begin(); it != it_end; ++ it, ++i)
2921	{
2922	Polygon3 poly = it;
2923	Add(new Polygon3(*poly), rhs.mPlanes[i]);
2924	}
2925	}
2926
2927
2928	BspNodeGeometry& BspNodeGeometry::operator=(const BspNodeGeometry& g)
2929	{
2930	if (this == &g)
2931	return *this;
2932
2933	CLEAR_CONTAINER(mPolys);
2934
2935	mPolys.reserve(g.mPolys.size());
2936	mPlanes.reserve(g.mPolys.size());
2937
2938	PolygonContainer::const_iterator it, it_end = g.mPolys.end();
2939
2940	int i = 0;
2941
2942	for (it = g.mPolys.begin(); it != it_end; ++ it, ++ i)
2943	{
2944	Polygon3 poly = it;
2945	Add(new Polygon3(*poly), g.mPlanes[i]);
2946	}
2947
2948	return *this;
2949	}
2950
2951
2952	BspNodeGeometry::BspNodeGeometry(const PolygonContainer &polys)
2953	{
2954	mPolys = polys;
2955	mPlanes.reserve(polys.size());
2956
2957	PolygonContainer::const_iterator it, it_end = polys.end();
2958
2959	for (it = polys.begin(); it != it_end; ++ it)
2960	{
2961	Polygon3 poly = it;
2962	mPlanes.push_back(poly->GetSupportingPlane());
2963	}
2964	}
2965
2966
2967	BspNodeGeometry::~BspNodeGeometry()
2968	{
2969	CLEAR_CONTAINER(mPolys);
2970	}
2971
2972
2973	int BspNodeGeometry::Size() const
2974	{
2975	return (int)mPolys.size();
2976	}
2977
2978
2979	const PolygonContainer &BspNodeGeometry::GetPolys()
2980	{
2981	return mPolys;
2982	}
2983
2984
2985	void BspNodeGeometry::Add(Polygon3 *p, const Plane3 &plane)
2986	{
2987	mPolys.push_back(p);
2988	mPlanes.push_back(plane);
2989	}
2990
2991
2992	float BspNodeGeometry::GetArea() const
2993	{
2994	return Polygon3::GetArea(mPolys);
2995	}
2996
2997
2998	float BspNodeGeometry::GetVolume() const
2999	{
3000	//-- compute volume using tetrahedralization of the geometry
3001	// and adding the volume of the single tetrahedrons
3002	float volume = 0;
3003	const float f = 1.0f / 6.0f;
3004
3005	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
3006
3007	// note: can take arbitrary point, e.g., the origin. However,
3008	// we rather take the center of mass to prevents precision errors
3009	const Vector3 center = CenterOfMass();
3010
3011	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
3012	{
3013	Polygon3 poly = pit;
3014	const Vector3 v0 = poly->mVertices[0] - center;
3015
3016	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
3017	{
3018	const Vector3 v1 = poly->mVertices[i] - center;
3019	const Vector3 v2 = poly->mVertices[i + 1] - center;
3020
3021	// more robust version using abs and the center of mass
3022	volume += fabs (f * (DotProd(v0, CrossProd(v1, v2))));
3023	}
3024	}
3025
3026	return volume;
3027	}
3028
3029
3030	void BspNodeGeometry::GetBoundingBox(AxisAlignedBox3 &box) const
3031	{
3032	box.Initialize();
3033	box.Include(mPolys);
3034	}
3035
3036
3037	int BspNodeGeometry::Side(const Plane3 &plane, const float eps) const
3038	{
3039	PolygonContainer::const_iterator it, it_end = mPolys.end();
3040
3041	bool onFrontSide = false;
3042	bool onBackSide = false;
3043
3044	for (it = mPolys.begin(); it != it_end; ++ it)
3045	{
3046	const int side = (*it)->Side(plane, eps);
3047
3048	if (side == -1)
3049	onBackSide = true;
3050	else if (side == 1)
3051	onFrontSide = true;
3052
3053	if ((side == 0) \|\| (onBackSide && onFrontSide))
3054	return 0;
3055	}
3056
3057	if (onFrontSide)
3058	return 1;
3059
3060	return -1;
3061	}
3062
3063
3064	int BspNodeGeometry::ComputeIntersection(const AxisAlignedBox3 &box) const
3065	{
3066	// 1: box does not intersect geometry
3067	// 0: box intersects geometry
3068	// -1: box contains geometry
3069
3070	AxisAlignedBox3 boundingBox;
3071	GetBoundingBox(boundingBox);
3072
3073	// no intersections with bounding box
3074	if (!Overlap(box, boundingBox))
3075	{
3076	return 1;
3077	}
3078
3079	// box cotains bounding box of geometry >=> contains geometry
3080	if (box.Includes(boundingBox))
3081	return -1;
3082
3083	int result = 0;
3084
3085	// test geometry planes for intersections
3086	vector<Plane3>::const_iterator it, it_end = mPlanes.end();
3087
3088	for (it = mPlanes.begin(); it != it_end; ++ it)
3089	{
3090	const int side = box.Side(*it);
3091
3092	// box does not intersects geometry
3093	if (side == 1)
3094	{
3095	return 1;
3096	}
3097	//if (side == 0) result = 0;
3098	}
3099
3100	return result;
3101	}
3102
3103
3104	Vector3 BspNodeGeometry::CenterOfMass() const
3105	{
3106	int n = 0;
3107
3108	Vector3 center(0,0,0);
3109
3110	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
3111
3112	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
3113	{
3114	Polygon3 poly = pit;
3115
3116	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
3117
3118	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
3119	{
3120	center += *vit;
3121	++ n;
3122	}
3123	}
3124
3125	//Debug << "center: " << center << " new " << center / (float)n << endl;
3126
3127	return center / (float)n;
3128	}
3129
3130
3131	bool BspNodeGeometry::Valid() const
3132	{
3133	// geometry is degenerated
3134	if (mPolys.size() < 4)
3135	return false;
3136
3137	return true;
3138	}
3139
3140	void IncludeNodeGeomInMesh(const BspNodeGeometry &geom, Mesh &mesh)
3141	{
3142	// add single polygons to mesh
3143	PolygonContainer::const_iterator it, it_end = geom.mPolys.end();
3144
3145	for (it = geom.mPolys.begin(); it != geom.mPolys.end(); ++ it)
3146	{
3147	Polygon3 poly = (it);
3148	IncludePolyInMesh(*poly, mesh);
3149	}
3150	}
3151
3152
3153	bool BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
3154	BspNodeGeometry &back,
3155	const Plane3 &splitPlane,
3156	const AxisAlignedBox3 &box,
3157	const float epsilon) const
3158	{
3159	//-- trivial cases
3160	if (0)
3161	{
3162	const int cf = Side(splitPlane, epsilon);
3163
3164	if (cf == -1)
3165	{
3166	back = *this;
3167	return false;
3168	}
3169	else if (cf == 1)
3170	{
3171	front = *this;
3172	return false;
3173	}
3174	}
3175
3176	// get cross section of new polygon
3177	Polygon3 *planePoly = box.CrossSection(splitPlane);
3178
3179	// split polygon with all other polygons
3180	planePoly = SplitPolygon(planePoly, epsilon);
3181
3182	bool splitsGeom = (planePoly != NULL);
3183
3184	//-- new polygon splits all other polygons
3185	for (int i = 0; i < (int)mPolys.size()/* && planePoly*/; ++ i)
3186	{
3187	/// don't use epsilon here to get exact split planes
3188	const int cf =
3189	mPolys[i]->ClassifyPlane(splitPlane, epsilon);
3190
3191	switch (cf)
3192	{
3193	case Polygon3::SPLIT:
3194	{
3195	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
3196
3197	Polygon3 *frontPoly = new Polygon3();
3198	Polygon3 *backPoly = new Polygon3();
3199
3200	poly->Split(splitPlane,
3201	*frontPoly,
3202	*backPoly,
3203	epsilon);
3204
3205	DEL_PTR(poly);
3206
3207	if (frontPoly->Valid(epsilon))
3208	{
3209	front.Add(frontPoly, mPlanes[i]);
3210	}
3211	else
3212	{
3213	//Debug << "no f! " << endl;
3214	DEL_PTR(frontPoly);
3215	}
3216
3217	if (backPoly->Valid(epsilon))
3218	{
3219	back.Add(backPoly, mPlanes[i]);
3220	}
3221	else
3222	{
3223	//Debug << "no b! " << endl;
3224	DEL_PTR(backPoly);
3225	}
3226	}
3227
3228	break;
3229	case Polygon3::BACK_SIDE:
3230	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3231	break;
3232	case Polygon3::FRONT_SIDE:
3233	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3234	break;
3235	// only put into back container (split should have no effect ...)
3236	case Polygon3::COINCIDENT:
3237	//Debug << "error should not come here" << endl;
3238	splitsGeom = false;
3239
3240	if (DotProd(mPlanes[i].mNormal, splitPlane.mNormal > 0))
3241	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3242	else
3243	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3244	break;
3245	default:
3246	break;
3247	}
3248	}
3249
3250	//-- finally add the new polygon to the child node geometries
3251	if (planePoly)
3252	{
3253	// add polygon with reverse orientation to front cell
3254	Plane3 reversePlane(splitPlane);
3255	reversePlane.ReverseOrientation();
3256
3257	// add polygon with normal pointing into positive half space to back cell
3258	back.Add(planePoly, splitPlane);
3259	//back.mPolys.push_back(planePoly);
3260
3261	Polygon3 *reversePoly = planePoly->CreateReversePolygon();
3262	front.Add(reversePoly, reversePlane);
3263	//Debug << "poly normal : " << reversePoly->GetSupportingPlane().mNormal << " split plane normal " << reversePlane.mNormal << endl;
3264	}
3265
3266
3267	return splitsGeom;
3268	}
3269
3270
3271	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3272	const float epsilon) const
3273	{
3274	if (!planePoly->Valid(epsilon))
3275	{
3276	//Debug << "not valid!!" << endl;
3277	DEL_PTR(planePoly);
3278	}
3279	// polygon is split by all other planes
3280	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3281	{
3282	//Plane3 plane = mPolys[i]->GetSupportingPlane();
3283	Plane3 plane = mPlanes[i];
3284
3285	/// don't use epsilon here to get exact split planes
3286	const int cf =
3287	planePoly->ClassifyPlane(plane, epsilon);
3288
3289	// split new polygon with all previous planes
3290	switch (cf)
3291	{
3292	case Polygon3::SPLIT:
3293	{
3294	Polygon3 *frontPoly = new Polygon3();
3295	Polygon3 *backPoly = new Polygon3();
3296
3297	planePoly->Split(plane,
3298	*frontPoly,
3299	*backPoly,
3300	epsilon);
3301
3302	// don't need anymore
3303	DEL_PTR(planePoly);
3304	DEL_PTR(frontPoly);
3305
3306	// back polygon is belonging to geometry
3307	if (backPoly->Valid(epsilon))
3308	planePoly = backPoly;
3309	else
3310	DEL_PTR(backPoly);
3311	}
3312	break;
3313	case Polygon3::FRONT_SIDE:
3314	DEL_PTR(planePoly);
3315	break;
3316	// polygon is taken as it is
3317	case Polygon3::BACK_SIDE:
3318	case Polygon3::COINCIDENT:
3319	default:
3320	break;
3321	}
3322	}
3323
3324	return planePoly;
3325	}
3326
3327
3328	ViewCell *BspTree::GetViewCell(const Vector3 &point)
3329	{
3330	if (mRoot == NULL)
3331	return NULL;
3332
3333	stack<BspNode *> nodeStack;
3334	nodeStack.push(mRoot);
3335
3336	ViewCellLeaf *viewcell = NULL;
3337
3338	while (!nodeStack.empty()) {
3339	BspNode *node = nodeStack.top();
3340	nodeStack.pop();
3341
3342	if (node->IsLeaf())
3343	{
3344	viewcell = static_cast<BspLeaf *>(node)->mViewCell;
3345	break;
3346	}
3347	else
3348	{
3349
3350	BspInterior interior = static_cast<BspInterior >(node);
3351
3352	// random decision
3353	if (interior->GetPlane().Side(point) < 0)
3354	{
3355	nodeStack.push(interior->GetBack());
3356	}
3357	else
3358	{
3359	nodeStack.push(interior->GetFront());
3360	}
3361	}
3362	}
3363
3364	return viewcell;
3365	}
3366
3367
3368	bool BspTree::Export(OUT_STREAM &stream)
3369	{
3370	ExportNode(mRoot, stream);
3371	return true;
3372	}
3373
3374
3375	void BspTree::ExportNode(BspNode *node, OUT_STREAM &stream)
3376	{
3377	if (node->IsLeaf())
3378	{
3379	BspLeaf leaf = static_cast<BspLeaf >(node);
3380	ViewCell *viewCell = mViewCellsTree->GetActiveViewCell(leaf->GetViewCell());
3381
3382	const int id = viewCell->GetId();
3383
3384	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3385	}
3386	else
3387	{
3388	BspInterior interior = static_cast<BspInterior >(node);
3389
3390	Plane3 plane = interior->GetPlane();
3391	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3392	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3393	<< plane.mD << "\">" << endl;
3394
3395	ExportNode(interior->GetBack(), stream);
3396	ExportNode(interior->GetFront(), stream);
3397
3398	stream << "</Interior>" << endl;
3399	}
3400	}
3401
3402
3403	}

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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 2609

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