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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 882

Revision 882, 80.7 KB checked in by mattausch, 18 years ago (diff)
added new active view cell concept

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

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