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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 840

Revision 840, 80.7 KB checked in by mattausch, 18 years ago (diff)
implementing bounding box hack

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

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