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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 418

Revision 418, 62.5 KB checked in by mattausch, 19 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include <stack>
11	#include <time.h>
12	#include <iomanip>
13	#include "Exporter.h"
14	#include "Plane3.h"
15
16	int BspTree::sMaxPolyCandidates = 10;
17	int BspTree::sMaxRayCandidates = 10;
18	int BspTree::sSplitPlaneStrategy = BALANCED_POLYS;
19	int BspTree::sConstructionMethod = FROM_INPUT_VIEW_CELLS;
20
21
22	int BspTree::sTermMaxPolygons = 10;
23	int BspTree::sTermMinPvs = 20;
24	int BspTree::sTermMaxDepth = 20;
25	float BspTree::sTermMinArea = 0.001f;
26	int BspTree::sTermMaxPolysForAxisAligned = 50;
27	int BspTree::sTermMaxObjectsForAxisAligned = 50;
28	int BspTree::sTermMaxRaysForAxisAligned = -1;
29	int BspTree::sTermMaxRays = -1;
30	float BspTree::sTermMaxRayContribution = 0.05f;
31	float BspTree::sTermMaxAccRayLength = 50;
32
33
34	int BspTree::sMinPvsDif = 10;
35	int BspTree::sMinPvs = 10;
36	int BspTree::sMaxPvs = 500;
37
38	float BspTree::sCt_div_ci = 1.0f;
39	float BspTree::sSplitBorder = 1.0f;
40	float BspTree::sMaxCostRatio = 0.9f;
41
42	//-- factors for bsp tree split plane heuristics
43
44	float BspTree::sLeastSplitsFactor = 1.0f;
45	float BspTree::sBalancedPolysFactor = 1.0f;
46	float BspTree::sBalancedViewCellsFactor = 1.0f;
47
48	// NOTE: very important criterium for 2.5d scenes
49	float BspTree::sVerticalSplitsFactor = 1.0f;
50	float BspTree::sLargestPolyAreaFactor = 1.0f;
51	float BspTree::sBlockedRaysFactor = 1.0f;
52	float BspTree::sLeastRaySplitsFactor = 1.0f;
53	float BspTree::sBalancedRaysFactor = 1.0f;
54	float BspTree::sPvsFactor = 1.0f;
55
56	bool BspTree::sStoreLeavesWithRays = false;
57	int BspNode::mailID = 1;
58
59	/** Evaluates split plane classification with respect to the plane's
60	contribution for a minimum number splits in the tree.
61	*/
62	float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
63	/** Evaluates split plane classification with respect to the plane's
64	contribution for a balanced tree.
65	*/
66	float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
67
68	/** Evaluates split plane classification with respect to the plane's
69	contribution for a minimum number of ray splits.
70	*/
71	float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
72	/** Evaluates split plane classification with respect to the plane's
73	contribution for balanced rays.
74	*/
75	float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
76
77	bool BspTree::sPvsUseArea = true;
78
79	/****************************************************************/
80	/* class BspNode implementation */
81	/****************************************************************/
82
83	BspNode::BspNode():
84	mParent(NULL)
85	{}
86
87	BspNode::BspNode(BspInterior *parent):
88	mParent(parent)
89	{}
90
91
92	bool BspNode::IsRoot() const
93	{
94	return mParent == NULL;
95	}
96
97	BspInterior *BspNode::GetParent()
98	{
99	return mParent;
100	}
101
102	void BspNode::SetParent(BspInterior *parent)
103	{
104	mParent = parent;
105	}
106
107	/****************************************************************/
108	/* class BspInterior implementation */
109	/****************************************************************/
110
111
112	BspInterior::BspInterior(const Plane3 &plane):
113	mPlane(plane), mFront(NULL), mBack(NULL)
114	{}
115
116	BspInterior::~BspInterior()
117	{
118	DEL_PTR(mFront);
119	DEL_PTR(mBack);
120	}
121
122	bool BspInterior::IsLeaf() const
123	{
124	return false;
125	}
126
127	BspNode *BspInterior::GetBack()
128	{
129	return mBack;
130	}
131
132	BspNode *BspInterior::GetFront()
133	{
134	return mFront;
135	}
136
137	Plane3 *BspInterior::GetPlane()
138	{
139	return &mPlane;
140	}
141
142	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
143	{
144	if (mBack == oldChild)
145	mBack = newChild;
146	else
147	mFront = newChild;
148	}
149
150	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
151	{
152	mBack = b;
153	mFront = f;
154	}
155
156	int BspInterior::SplitPolygons(PolygonContainer &polys,
157	PolygonContainer &frontPolys,
158	PolygonContainer &backPolys,
159	PolygonContainer &coincident)
160	{
161	Polygon3 *splitPoly = NULL;
162
163	int splits = 0;
164
165	#ifdef _Debug
166	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
167	#endif
168	while (!polys.empty())
169	{
170	Polygon3 *poly = polys.back();
171	polys.pop_back();
172
173	//Debug << "New polygon with plane: " << poly->GetSupportingPlane() << "\n";
174
175	// classify polygon
176	const int cf = poly->ClassifyPlane(mPlane);
177
178	Polygon3 *front_piece = NULL;
179	Polygon3 *back_piece = NULL;
180
181	VertexContainer splitVertices;
182
183	switch (cf)
184	{
185	case Polygon3::COINCIDENT:
186	coincident.push_back(poly);
187	break;
188	case Polygon3::FRONT_SIDE:
189	frontPolys.push_back(poly);
190	break;
191	case Polygon3::BACK_SIDE:
192	backPolys.push_back(poly);
193	break;
194	case Polygon3::SPLIT:
195	front_piece = new Polygon3(poly->mParent);
196	back_piece = new Polygon3(poly->mParent);
197
198	//-- split polygon into front and back part
199	poly->Split(mPlane,
200	*front_piece,
201	*back_piece,
202	splitVertices);
203
204	++ splits; // increase number of splits
205
206	//-- inherit rays from parent polygon for blocked ray criterium
207	poly->InheritRays(front_piece, back_piece);
208	//Debug << "p: " << poly->mPiercingRays.size() << " f: " << front_piece->mPiercingRays.size() << " b: " << back_piece->mPiercingRays.size() << endl;
209
210	// check if polygons still valid
211	if (front_piece->Valid())
212	frontPolys.push_back(front_piece);
213	else
214	DEL_PTR(front_piece);
215
216	if (back_piece->Valid())
217	backPolys.push_back(back_piece);
218	else
219	DEL_PTR(back_piece);
220
221	#ifdef _DEBUG
222	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
223	#endif
224	DEL_PTR(poly);
225	break;
226	default:
227	Debug << "SHOULD NEVER COME HERE\n";
228	break;
229	}
230	}
231
232	return splits;
233	}
234
235	/****************************************************************/
236	/* class BspLeaf implementation */
237	/****************************************************************/
238	BspLeaf::BspLeaf(): mViewCell(NULL)
239	{
240	}
241
242	BspLeaf::BspLeaf(BspViewCell *viewCell):
243	mViewCell(viewCell)
244	{
245	}
246
247	BspLeaf::BspLeaf(BspInterior *parent):
248	BspNode(parent), mViewCell(NULL)
249	{}
250
251	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
252	BspNode(parent), mViewCell(viewCell)
253	{
254	}
255
256	BspViewCell *BspLeaf::GetViewCell() const
257	{
258	return mViewCell;
259	}
260
261	void BspLeaf::SetViewCell(BspViewCell *viewCell)
262	{
263	mViewCell = viewCell;
264	}
265
266	bool BspLeaf::IsLeaf() const
267	{
268	return true;
269	}
270
271	void BspLeaf::AddToPvs(const BoundedRayContainer &rays,
272	int &sampleContributions,
273	int &contributingSamples)
274	{
275	sampleContributions = 0;
276	contributingSamples = 0;
277
278	BoundedRayContainer::const_iterator it, it_end = rays.end();
279
280	// add contributions from samples to the PVS
281	for (it = rays.begin(); it != it_end; ++ it)
282	{
283	int contribution = 0;
284	Ray ray = (it)->mRay;
285
286	if (!ray->intersections.empty())
287	contribution += mViewCell->GetPvs().AddSample(ray->intersections[0].mObject);
288
289	if (ray->sourceObject.mObject)
290	contribution += mViewCell->GetPvs().AddSample(ray->sourceObject.mObject);
291
292	if (contribution > 0)
293	{
294	sampleContributions += contribution;
295	++ contributingSamples;
296	}
297
298	if (BspTree::sStoreLeavesWithRays)
299	// warning: intersections not ordered
300	ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
301	}
302	}
303
304
305	/****************************************************************/
306	/* class BspTree implementation */
307	/****************************************************************/
308
309	BspTree::BspTree(BspViewCell *viewCell):
310	mRootCell(viewCell), mRoot(NULL), mGenerateViewCells(false),
311	mStorePiercingRays(true)
312	{
313	Randomize(); // initialise random generator for heuristics
314	}
315
316	const BspTreeStatistics &BspTree::GetStatistics() const
317	{
318	return mStat;
319	}
320
321	void BspTreeStatistics::Print(ostream &app) const
322	{
323	app << "===== BspTree statistics ===============\n";
324
325	app << setprecision(4);
326
327	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
328
329	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
330
331	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
332
333	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
334
335	app << "#N_SPLITS ( Number of splits )\n" << splits << "\n";
336
337	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maxdepth )\n"<<
338	maxDepthNodes * 100 / (double)Leaves() << endl;
339
340	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
341
342	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
343
344	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
345
346	app << "#N_INPUT_POLYGONS (number of input polygons )\n" << polys << endl;
347
348	//app << "#N_PVS: " << pvs << endl;
349
350	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
351	(polys + splits) / (double)polys << endl;
352
353	app << "===== END OF BspTree statistics ==========\n";
354	}
355
356
357	BspTree::~BspTree()
358	{
359	DEL_PTR(mRoot);
360	}
361
362	void BspTree::InsertViewCell(ViewCell *viewCell)
363	{
364	PolygonContainer *polys = new PolygonContainer();
365
366	// extract polygons that guide the split process
367	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
368	mBox.Include(viewCell->GetBox()); // add to BSP aabb
369
370	InsertPolygons(polys);
371	}
372
373	void BspTree::InsertPolygons(PolygonContainer *polys)
374	{
375	std::stack<BspTraversalData> tStack;
376
377	// traverse existing tree or create new tree
378	if (!mRoot)
379	mRoot = new BspLeaf();
380
381	tStack.push(BspTraversalData(mRoot, polys, 0, mRootCell, new BoundedRayContainer(), 0,
382	mBox.SurfaceArea(), new BspNodeGeometry()));
383
384	while (!tStack.empty())
385	{
386	// filter polygons donw the tree
387	BspTraversalData tData = tStack.top();
388	tStack.pop();
389
390	if (!tData.mNode->IsLeaf())
391	{
392	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
393
394	//-- filter view cell polygons down the tree until a leaf is reached
395	if (!tData.mPolygons->empty())
396	{
397	PolygonContainer *frontPolys = new PolygonContainer();
398	PolygonContainer *backPolys = new PolygonContainer();
399	PolygonContainer coincident;
400
401	int splits = 0;
402
403	// split viewcell polygons with respect to split plane
404	splits += interior->SplitPolygons(*tData.mPolygons,
405	*frontPolys,
406	*backPolys,
407	coincident);
408
409	// extract view cells associated with the split polygons
410	ViewCell *frontViewCell = mRootCell;
411	ViewCell *backViewCell = mRootCell;
412
413	BspTraversalData frontData(interior->GetFront(),
414	frontPolys,
415	tData.mDepth + 1,
416	mRootCell,
417	tData.mRays,
418	tData.mPvs,
419	mBox.SurfaceArea(),
420	new BspNodeGeometry());
421
422	BspTraversalData backData(interior->GetBack(),
423	backPolys,
424	tData.mDepth + 1,
425	mRootCell,
426	tData.mRays,
427	tData.mPvs,
428	mBox.SurfaceArea(),
429	new BspNodeGeometry());
430
431	if (!mGenerateViewCells)
432	{
433	ExtractViewCells(frontData,
434	backData,
435	coincident,
436	interior->mPlane);
437	}
438
439	// don't need coincident polygons anymore
440	CLEAR_CONTAINER(coincident);
441
442	mStat.splits += splits;
443
444	// push the children on the stack
445	tStack.push(frontData);
446	tStack.push(backData);
447	}
448
449	// cleanup
450	DEL_PTR(tData.mPolygons);
451	}
452	else
453	{
454	// reached leaf => subdivide current viewcell
455	BspNode *subRoot = Subdivide(tStack, tData);
456	}
457	}
458	}
459
460	int BspTree::AddMeshToPolygons(Mesh mesh, PolygonContainer &polys, MeshInstance parent)
461	{
462	FaceContainer::const_iterator fi;
463
464	// copy the face data to polygons
465	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
466	{
467	Polygon3 poly = new Polygon3((fi), mesh);
468
469	if (poly->Valid())
470	{
471	poly->mParent = parent; // set parent intersectable
472	polys.push_back(poly);
473	}
474	else
475	DEL_PTR(poly);
476	}
477	return (int)mesh->mFaces.size();
478	}
479
480	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
481	PolygonContainer &polys,
482	int maxObjects)
483	{
484	int limit = (maxObjects > 0) ?
485	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
486
487	int polysSize = 0;
488
489	for (int i = 0; i < limit; ++ i)
490	{
491	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
492	{
493	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
494	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
495	}
496	}
497
498	return polysSize;
499	}
500
501	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
502	{
503	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
504
505	for (int i = 0; i < limit; ++i)
506	{
507	Intersectable object = objects[i];//it;
508	Mesh *mesh = NULL;
509
510	switch (object->Type()) // extract the meshes
511	{
512	case Intersectable::MESH_INSTANCE:
513	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
514	break;
515	case Intersectable::VIEW_CELL:
516	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
517	break;
518	// TODO: handle transformed mesh instances
519	default:
520	Debug << "intersectable type not supported" << endl;
521	break;
522	}
523
524	if (mesh) // copy the mesh data to polygons
525	{
526	mBox.Include(object->GetBox()); // add to BSP tree aabb
527	AddMeshToPolygons(mesh, polys, mRootCell);
528	}
529	}
530
531	return (int)polys.size();
532	}
533
534	void BspTree::Construct(const ViewCellContainer &viewCells)
535	{
536	mStat.nodes = 1;
537	mBox.Initialize(); // initialise bsp tree bounding box
538
539	// copy view cell meshes into one big polygon soup
540	PolygonContainer *polys = new PolygonContainer();
541	mStat.polys = AddToPolygonSoup(viewCells, *polys);
542
543	// construct tree from the view cell polygons
544	Construct(polys, new BoundedRayContainer());
545	}
546
547
548	void BspTree::Construct(const ObjectContainer &objects)
549	{
550	mStat.nodes = 1;
551	mBox.Initialize(); // initialise bsp tree bounding box
552
553	PolygonContainer *polys = new PolygonContainer();
554
555	// copy mesh instance polygons into one big polygon soup
556	mStat.polys = AddToPolygonSoup(objects, *polys);
557
558	// construct tree from polygon soup
559	Construct(polys, new BoundedRayContainer());
560	}
561
562	void BspTree::Construct(const RayContainer &sampleRays)
563	{
564	mStat.nodes = 1;
565	mBox.Initialize(); // initialise BSP tree bounding box
566
567	PolygonContainer *polys = new PolygonContainer();
568	BoundedRayContainer *rays = new BoundedRayContainer();
569
570	RayContainer::const_iterator rit, rit_end = sampleRays.end();
571
572	long startTime = GetTime();
573
574	Debug << "** Extracting polygons from rays **\n";
575
576	std::map<Face , Polygon3 > facePolyMap;
577
578	//-- extract polygons intersected by the rays
579	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
580	{
581	Ray ray = rit;
582
583	// get ray-face intersection. Store polygon representing the rays together
584	// with rays intersecting the face.
585	if (!ray->intersections.empty())
586	{
587	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
588	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
589
590	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
591
592	if (it != facePolyMap.end())
593	{
594	//store rays if needed for heuristics
595	if (sSplitPlaneStrategy & BLOCKED_RAYS)
596	(*it).second->mPiercingRays.push_back(ray);
597	}
598	else
599	{ //store rays if needed for heuristics
600	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
601	poly->mParent = obj;
602	polys->push_back(poly);
603
604	if (sSplitPlaneStrategy & BLOCKED_RAYS)
605	poly->mPiercingRays.push_back(ray);
606
607	facePolyMap[face] = poly;
608	}
609	}
610	}
611
612	facePolyMap.clear();
613
614	// compue bounding box
615	Polygon3::IncludeInBox(*polys, mBox);
616
617	//-- store rays
618	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
619	{
620	Ray ray = rit;
621	ray->SetId(-1); // reset id
622
623	float minT, maxT;
624	if (BoundRay(*ray, minT, maxT))
625	rays->push_back(new BoundedRay(ray, minT, maxT));
626	}
627
628	mStat.polys = (int)polys->size();
629
630	Debug << "** Finished polygon extraction **" << endl;
631	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
632	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
633
634	Construct(polys, rays);
635	}
636
637	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
638	{
639	std::stack<BspTraversalData> tStack;
640
641	mRoot = new BspLeaf();
642
643	BspNodeGeometry *cell = new BspNodeGeometry();
644	ConstructGeometry(mRoot, *cell);
645
646	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
647	ComputePvsSize(*rays), cell->GetArea(), cell);
648
649	tStack.push(tData);
650
651	mStat.Start();
652	cout << "** Contructing bsp tree **\n";
653
654	while (!tStack.empty())
655	{
656	tData = tStack.top();
657	tStack.pop();
658
659	// subdivide leaf node
660	BspNode *subRoot = Subdivide(tStack, tData);
661	}
662
663	mStat.Stop();
664	}
665
666	inline bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
667	{
668	return
669	(((int)data.mPolygons->size() <= sTermMaxPolygons) \|\|
670	((int)data.mRays->size() <= sTermMaxRays) \|\|
671	(data.mPvs <= sTermMinPvs) \|\|
672	(data.mArea <= sTermMinArea) \|\|
673	(data.mDepth >= sTermMaxDepth) \|\|
674	(((float)data.mPvs / (float)data.mRays->size()) < sTermMaxRayContribution));
675	}
676
677	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
678	{
679	//-- terminate traversal
680	if (TerminationCriteriaMet(tData))
681	{
682	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
683
684	BspViewCell *viewCell;
685
686	// generate new view cell for each leaf
687	if (mGenerateViewCells)
688	{
689	viewCell = dynamic_cast<BspViewCell *>(ViewCell::Generate());
690	}
691	else
692	{
693	// add view cell to leaf
694	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
695	}
696
697	leaf->SetViewCell(viewCell);
698	viewCell->mBspLeaves.push_back(leaf);
699
700	//-- add pvs
701	if (viewCell != mRootCell)
702	{
703	int conSamp = 0, sampCon = 0;
704	leaf->AddToPvs(*tData.mRays, conSamp, sampCon);
705
706	mStat.contributingSamples += conSamp;
707	mStat.sampleContributions += sampCon;
708	}
709
710	EvaluateLeafStats(tData);
711
712	//-- clean up
713
714	// discard polygons
715	CLEAR_CONTAINER(*tData.mPolygons);
716	// discard rays
717	CLEAR_CONTAINER(*tData.mRays);
718
719	DEL_PTR(tData.mPolygons);
720	DEL_PTR(tData.mRays);
721	DEL_PTR(tData.mGeometry);
722
723	return leaf;
724	}
725
726	//-- continue subdivision
727	PolygonContainer coincident;
728
729	PolygonContainer *frontPolys = new PolygonContainer();
730	PolygonContainer *backPolys = new PolygonContainer();
731
732	BoundedRayContainer *frontRays = new BoundedRayContainer();
733	BoundedRayContainer *backRays = new BoundedRayContainer();
734
735	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
736	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
737	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
738	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
739
740	// create new interior node and two leaf nodes
741	BspInterior *interior = SubdivideNode(tData,
742	tFrontData,
743	tBackData,
744	coincident);
745
746	#ifdef _DEBUG
747	if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
748	{ for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
749	Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
750	Debug << endl;}
751	#endif
752
753	// extract view cells from coincident polygons according to plane normal
754	// only if front or back polygons are empty
755	if (!mGenerateViewCells)
756	{
757	ExtractViewCells(tFrontData,
758	tBackData,
759	coincident,
760	interior->mPlane);
761
762	}
763
764	// don't need coincident polygons anymory
765	CLEAR_CONTAINER(coincident);
766
767	// push the children on the stack
768	tStack.push(tFrontData);
769	tStack.push(tBackData);
770
771	// cleanup
772	DEL_PTR(tData.mNode);
773	DEL_PTR(tData.mPolygons);
774	DEL_PTR(tData.mRays);
775	DEL_PTR(tData.mGeometry);
776
777	return interior;
778	}
779
780	void BspTree::ExtractViewCells(BspTraversalData &frontData,
781	BspTraversalData &backData,
782	const PolygonContainer &coincident,
783	const Plane3 splitPlane) const
784	{
785	// if not empty, tree is further subdivided => don't have to find view cell
786	bool foundFront = !frontData.mPolygons->empty();
787	bool foundBack = !frontData.mPolygons->empty();
788
789	PolygonContainer::const_iterator it =
790	coincident.begin(), it_end = coincident.end();
791
792	//-- find first view cells in front and back leafs
793	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
794	{
795	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
796	{
797	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
798	foundBack = true;
799	}
800	else
801	{
802	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
803	foundFront = true;
804	}
805	}
806	}
807
808	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
809	BspTraversalData &frontData,
810	BspTraversalData &backData,
811	PolygonContainer &coincident)
812	{
813	mStat.nodes += 2;
814
815	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
816	// select subdivision plane
817	BspInterior *interior =
818	new BspInterior(SelectPlane(leaf, tData));
819
820	#ifdef _DEBUG
821	Debug << interior << endl;
822	#endif
823
824	// subdivide rays into front and back rays
825	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
826
827	// subdivide polygons with plane
828	mStat.splits += interior->SplitPolygons(*tData.mPolygons,
829	*frontData.mPolygons,
830	*backData.mPolygons,
831	coincident);
832
833	// compute pvs
834	frontData.mPvs = ComputePvsSize(*frontData.mRays);
835	backData.mPvs = ComputePvsSize(*backData.mRays);
836
837	// split geometry and compute area
838	if (1)
839	{
840	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
841	*backData.mGeometry,
842	*this,
843	interior->mPlane);
844
845
846	frontData.mArea = frontData.mGeometry->GetArea();
847	backData.mArea = backData.mGeometry->GetArea();
848	}
849
850	// compute accumulated ray length
851	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
852	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
853
854	//-- create front and back leaf
855
856	BspInterior *parent = leaf->GetParent();
857
858	// replace a link from node's parent
859	if (!leaf->IsRoot())
860	{
861	parent->ReplaceChildLink(leaf, interior);
862	interior->SetParent(parent);
863	}
864	else // new root
865	{
866	mRoot = interior;
867	}
868
869	// and setup child links
870	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
871
872	frontData.mNode = interior->mFront;
873	backData.mNode = interior->mBack;
874
875	//DEL_PTR(leaf);
876	return interior;
877	}
878
879	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
880	const int axis,
881	vector<SortableEntry> &splitCandidates) const
882	{
883	splitCandidates.clear();
884
885	int requestedSize = 2 * (int)polys.size();
886	// creates a sorted split candidates array
887	splitCandidates.reserve(requestedSize);
888
889	PolygonContainer::const_iterator it, it_end = polys.end();
890
891	AxisAlignedBox3 box;
892
893	// insert all queries
894	for(it = polys.begin(); it != it_end; ++ it)
895	{
896	box.Initialize();
897	box.Include((it));
898
899	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
900	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
901	}
902
903	stable_sort(splitCandidates.begin(), splitCandidates.end());
904	}
905
906
907	float BspTree::BestCostRatio(const PolygonContainer &polys,
908	const AxisAlignedBox3 &box,
909	const int axis,
910	float &position,
911	int &objectsBack,
912	int &objectsFront) const
913	{
914	vector<SortableEntry> splitCandidates;
915
916	SortSplitCandidates(polys, axis, splitCandidates);
917
918	// go through the lists, count the number of objects left and right
919	// and evaluate the following cost funcion:
920	// C = ct_div_ci + (ol + or)/queries
921
922	int objectsLeft = 0, objectsRight = (int)polys.size();
923
924	float minBox = box.Min(axis);
925	float maxBox = box.Max(axis);
926	float boxArea = box.SurfaceArea();
927
928	float minBand = minBox + sSplitBorder * (maxBox - minBox);
929	float maxBand = minBox + (1.0f - sSplitBorder) * (maxBox - minBox);
930
931	float minSum = 1e20f;
932	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
933
934	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
935	{
936	switch ((*ci).type)
937	{
938	case SortableEntry::POLY_MIN:
939	++ objectsLeft;
940	break;
941	case SortableEntry::POLY_MAX:
942	-- objectsRight;
943	break;
944	default:
945	break;
946	}
947
948	if ((ci).value > minBand && (ci).value < maxBand)
949	{
950	AxisAlignedBox3 lbox = box;
951	AxisAlignedBox3 rbox = box;
952	lbox.SetMax(axis, (*ci).value);
953	rbox.SetMin(axis, (*ci).value);
954
955	float sum = objectsLeft * lbox.SurfaceArea() +
956	objectsRight * rbox.SurfaceArea();
957
958	if (sum < minSum)
959	{
960	minSum = sum;
961	position = (*ci).value;
962
963	objectsBack = objectsLeft;
964	objectsFront = objectsRight;
965	}
966	}
967	}
968
969	float oldCost = (float)polys.size();
970	float newCost = sCt_div_ci + minSum / boxArea;
971	float ratio = newCost / oldCost;
972
973
974	#if 0
975	Debug << "====================" << endl;
976	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
977	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
978	#endif
979	return ratio;
980	}
981
982	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
983	const PolygonContainer &polys) const
984	{
985	AxisAlignedBox3 box;
986	box.Initialize();
987
988	// create bounding box of region
989	Polygon3::IncludeInBox(polys, box);
990
991	int objectsBack = 0, objectsFront = 0;
992	int axis = 0;
993	float costRatio = MAX_FLOAT;
994	Vector3 position;
995
996	//-- area subdivision
997	for (int i = 0; i < 3; ++ i)
998	{
999	float p = 0;
1000	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1001
1002	if (r < costRatio)
1003	{
1004	costRatio = r;
1005	axis = i;
1006	position = p;
1007	}
1008	}
1009
1010	if (costRatio >= sMaxCostRatio)
1011	return false;
1012
1013	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1014	plane = Plane3(norm, position);
1015
1016	return true;
1017	}
1018
1019	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1020	{
1021	if (data.mPolygons->empty() && data.mRays->empty())
1022	{
1023	Debug << "Warning: No autopartition polygon candidate available\n";
1024
1025	// return axis aligned split
1026	AxisAlignedBox3 box;
1027	box.Initialize();
1028
1029	// create bounding box of region
1030	Polygon3::IncludeInBox(*data.mPolygons, box);
1031
1032	const int axis = box.Size().DrivingAxis();
1033	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1034
1035	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1036	return Plane3(norm, position);
1037	}
1038
1039	if ((sSplitPlaneStrategy & AXIS_ALIGNED) &&
1040	((int)data.mPolygons->size() > sTermMaxPolysForAxisAligned) &&
1041	((int)data.mRays->size() > sTermMaxRaysForAxisAligned) &&
1042	((sTermMaxObjectsForAxisAligned < 0) \|\|
1043	(Polygon3::ParentObjectsSize(*data.mPolygons) > sTermMaxObjectsForAxisAligned)))
1044	{
1045	Plane3 plane;
1046	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1047	return plane;
1048	}
1049
1050	// simplest strategy: just take next polygon
1051	if (sSplitPlaneStrategy & RANDOM_POLYGON)
1052	{
1053	if (!data.mPolygons->empty())
1054	{
1055	Polygon3 nextPoly = (data.mPolygons)[Random((int)data.mPolygons->size())];
1056	return nextPoly->GetSupportingPlane();
1057	}
1058	else
1059	{
1060	const int candidateIdx = Random((int)data.mRays->size());
1061	BoundedRay bRay = (data.mRays)[candidateIdx];
1062
1063	Ray *ray = bRay->mRay;
1064
1065	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1066	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1067
1068	const Vector3 pt = (maxPt + minPt) * 0.5;
1069
1070	const Vector3 normal = ray->GetDir();
1071
1072	return Plane3(normal, pt);
1073	}
1074
1075	return Plane3();
1076	}
1077
1078	// use heuristics to find appropriate plane
1079	return SelectPlaneHeuristics(leaf, data);
1080	}
1081
1082	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1083	{
1084	float lowestCost = MAX_FLOAT;
1085	Plane3 bestPlane;
1086	Plane3 plane;
1087
1088	int limit = Min((int)data.mPolygons->size(), sMaxPolyCandidates);
1089
1090	int candidateIdx = limit;
1091
1092	for (int i = 0; i < limit; ++ i)
1093	{
1094	candidateIdx = GetNextCandidateIdx(candidateIdx, *data.mPolygons);
1095
1096	Polygon3 poly = (data.mPolygons)[candidateIdx];
1097	// evaluate current candidate
1098	const float candidateCost =
1099	SplitPlaneCost(poly->GetSupportingPlane(), data);
1100
1101	if (candidateCost < lowestCost)
1102	{
1103	bestPlane = poly->GetSupportingPlane();
1104	lowestCost = candidateCost;
1105	}
1106	}
1107
1108	//Debug << "lowest: " << lowestCost << endl;
1109
1110	//-- choose candidate planes extracted from rays
1111	// we currently use two methods
1112	// 1) take 3 ray endpoints, where two are minimum and one a maximum
1113	// point or the other way round
1114	// 2) take plane normal as plane normal and the midpoint of the ray.
1115	// PROBLEM: does not resemble any point where visibility is likely to change
1116	const BoundedRayContainer *rays = data.mRays;
1117
1118	for (int i = 0; i < sMaxRayCandidates / 2; ++ i)
1119	{
1120	candidateIdx = Random((int)rays->size());
1121	BoundedRay bRay = (rays)[candidateIdx];
1122
1123	Ray *ray = bRay->mRay;
1124
1125	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1126	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1127
1128	const Vector3 pt = (maxPt + minPt) * 0.5;
1129
1130	const Vector3 normal = ray->GetDir();
1131
1132	plane = Plane3(normal, pt);
1133
1134	const float candidateCost = SplitPlaneCost(plane, data);
1135
1136	if (candidateCost < lowestCost)
1137	{
1138	bestPlane = plane;
1139
1140	lowestCost = candidateCost;
1141	}
1142	}
1143
1144	//Debug << "lowest: " << lowestCost << endl;
1145
1146	for (int i = 0; i < sMaxRayCandidates / 2; ++ i)
1147	{
1148	Vector3 pt[3];
1149	int idx[3];
1150	int cmaxT = 0;
1151	int cminT = 0;
1152	bool chooseMin = false;
1153
1154	for (int j = 0; j < 3; j ++)
1155	{
1156	idx[j] = Random((int)rays->size() * 2);
1157
1158	if (idx[j] >= (int)rays->size())
1159	{
1160	idx[j] -= (int)rays->size();
1161
1162	chooseMin = (cminT < 2);
1163	}
1164	else
1165	chooseMin = (cmaxT < 2);
1166
1167	BoundedRay bRay = (rays)[idx[j]];
1168	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) : bRay->mRay->Extrap(bRay->mMaxT);
1169	}
1170
1171	plane = Plane3(pt[0], pt[1], pt[2]);
1172
1173	const float candidateCost = SplitPlaneCost(plane, data);
1174
1175	if (candidateCost < lowestCost)
1176	{
1177	//Debug << "choose ray plane 2: " << candidateCost << endl;
1178	bestPlane = plane;
1179
1180	lowestCost = candidateCost;
1181	}
1182	}
1183
1184	#ifdef _DEBUG
1185	Debug << "plane lowest cost: " << lowestCost << endl;
1186	#endif
1187	return bestPlane;
1188	}
1189
1190	int BspTree::GetNextCandidateIdx(int currentIdx, PolygonContainer &polys)
1191	{
1192	const int candidateIdx = Random(currentIdx --);
1193
1194	// swap candidates to avoid testing same plane 2 times
1195	std::swap(polys[currentIdx], polys[candidateIdx]);
1196
1197	return currentIdx;
1198	//return Random((int)polys.size());
1199	}
1200
1201	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1202	const PolygonContainer &polys) const
1203	{
1204	float val = 0;
1205
1206	float sumBalancedPolys = 0;
1207	float sumSplits = 0;
1208	float sumPolyArea = 0;
1209	float sumBalancedViewCells = 0;
1210	float sumBlockedRays = 0;
1211	float totalBlockedRays = 0;
1212	//float totalArea = 0;
1213	int totalViewCells = 0;
1214
1215	// need three unique ids for each type of view cell
1216	// for balanced view cells criterium
1217	ViewCell::NewMail();
1218	const int backId = ViewCell::sMailId;
1219	ViewCell::NewMail();
1220	const int frontId = ViewCell::sMailId;
1221	ViewCell::NewMail();
1222	const int frontAndBackId = ViewCell::sMailId;
1223
1224	PolygonContainer::const_iterator it, it_end = polys.end();
1225
1226	for (it = polys.begin(); it != it_end; ++ it)
1227	{
1228	const int classification = (*it)->ClassifyPlane(candidatePlane);
1229
1230	if (sSplitPlaneStrategy & BALANCED_POLYS)
1231	sumBalancedPolys += sBalancedPolysTable[classification];
1232
1233	if (sSplitPlaneStrategy & LEAST_SPLITS)
1234	sumSplits += sLeastPolySplitsTable[classification];
1235
1236	if (sSplitPlaneStrategy & LARGEST_POLY_AREA)
1237	{
1238	if (classification == Polygon3::COINCIDENT)
1239	sumPolyArea += (*it)->GetArea();
1240	//totalArea += area;
1241	}
1242
1243	if (sSplitPlaneStrategy & BLOCKED_RAYS)
1244	{
1245	const float blockedRays = (float)(*it)->mPiercingRays.size();
1246
1247	if (classification == Polygon3::COINCIDENT)
1248	sumBlockedRays += blockedRays;
1249
1250	totalBlockedRays += blockedRays;
1251	}
1252
1253	// assign view cells to back or front according to classificaion
1254	if (sSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1255	{
1256	MeshInstance viewCell = (it)->mParent;
1257
1258	// assure that we only count a view cell
1259	// once for the front and once for the back side of the plane
1260	if (classification == Polygon3::FRONT_SIDE)
1261	{
1262	if ((viewCell->mMailbox != frontId) &&
1263	(viewCell->mMailbox != frontAndBackId))
1264	{
1265	sumBalancedViewCells += 1.0;
1266
1267	if (viewCell->mMailbox != backId)
1268	viewCell->mMailbox = frontId;
1269	else
1270	viewCell->mMailbox = frontAndBackId;
1271
1272	++ totalViewCells;
1273	}
1274	}
1275	else if (classification == Polygon3::BACK_SIDE)
1276	{
1277	if ((viewCell->mMailbox != backId) &&
1278	(viewCell->mMailbox != frontAndBackId))
1279	{
1280	sumBalancedViewCells -= 1.0;
1281
1282	if (viewCell->mMailbox != frontId)
1283	viewCell->mMailbox = backId;
1284	else
1285	viewCell->mMailbox = frontAndBackId;
1286
1287	++ totalViewCells;
1288	}
1289	}
1290	}
1291	}
1292
1293	// all values should be approx. between 0 and 1 so they can be combined
1294	// and scaled with the factors according to their importance
1295	if ((sSplitPlaneStrategy & BALANCED_POLYS) && (!polys.empty()))
1296	val += sBalancedPolysFactor * fabs(sumBalancedPolys) / (float)polys.size();
1297
1298	if ((sSplitPlaneStrategy & LEAST_SPLITS) && (!polys.empty()))
1299	val += sLeastSplitsFactor * sumSplits / (float)polys.size();
1300
1301	if (sSplitPlaneStrategy & LARGEST_POLY_AREA)
1302	// HACK: polys.size should be total area so scaling is between 0 and 1
1303	val += sLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1304
1305	if (sSplitPlaneStrategy & BLOCKED_RAYS)
1306	if (totalBlockedRays != 0)
1307	val += sBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1308
1309	if (sSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1310	if (totalViewCells != 0)
1311	val += sBalancedViewCellsFactor * fabs(sumBalancedViewCells) / (float)totalViewCells;
1312
1313	return val;
1314	}
1315
1316	bool BspTree::BoundRay(const Ray &ray, float &minT, float &maxT) const
1317	{
1318	maxT = 1e6;
1319	minT = 0;
1320
1321	// test with tree bounding box
1322	if (!mBox.GetMinMaxT(ray, &minT, &maxT))
1323	return false;
1324
1325	if (minT < 0) // start ray from origin
1326	minT = 0;
1327
1328	// bound ray or line segment
1329	if ((ray.GetType() == Ray::LOCAL_RAY) &&
1330	!ray.intersections.empty() &&
1331	(ray.intersections[0].mT <= maxT))
1332	{
1333	maxT = ray.intersections[0].mT;
1334	}
1335
1336	return true;
1337	}
1338
1339	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1340	const BoundedRayContainer &rays,
1341	const int pvs,
1342	const float area,
1343	const BspNodeGeometry &cell) const
1344	{
1345	float val = 0;
1346
1347	float sumBalancedRays = 0;
1348	float sumRaySplits = 0;
1349
1350	int backId = 0;
1351	int frontId = 0;
1352	int frontAndBackId = 0;
1353
1354	int frontPvs = 0;
1355	int backPvs = 0;
1356
1357	// probability that view point lies in child
1358	float pOverall = 0;
1359	float pFront = 0;
1360	float pBack = 0;
1361
1362	if (sSplitPlaneStrategy & PVS)
1363	{
1364	// create three unique ids for pvs heuristics
1365	Intersectable::NewMail(); backId = ViewCell::sMailId;
1366	Intersectable::NewMail(); frontId = ViewCell::sMailId;
1367	Intersectable::NewMail(); frontAndBackId = ViewCell::sMailId;
1368
1369	if (sPvsUseArea) // use front and back cell areas to approximate volume
1370	{
1371	// construct child geometry with regard to the candidate split plane
1372	BspNodeGeometry frontCell;
1373	BspNodeGeometry backCell;
1374
1375	cell.SplitGeometry(frontCell, backCell, *this, candidatePlane);
1376
1377	pFront = frontCell.GetArea();
1378	pBack = backCell.GetArea();
1379
1380	pOverall = area;
1381	}
1382	}
1383
1384	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
1385
1386	for (rit = rays.begin(); rit != rays.end(); ++ rit)
1387	{
1388	Ray ray = (rit)->mRay;
1389	const float minT = (*rit)->mMinT;
1390	const float maxT = (*rit)->mMaxT;
1391
1392	Vector3 entP, extP;
1393
1394	const int cf =
1395	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1396
1397	if (sSplitPlaneStrategy & LEAST_RAY_SPLITS)
1398	{
1399	sumBalancedRays += sBalancedRaysTable[cf];
1400	}
1401
1402	if (sSplitPlaneStrategy & BALANCED_RAYS)
1403	{
1404	sumRaySplits += sLeastRaySplitsTable[cf];
1405	}
1406
1407	if (sSplitPlaneStrategy & PVS)
1408	{
1409	if (!ray->intersections.empty())
1410	{
1411	// in case the ray intersects an objcrs
1412	// assure that we only count a object
1413	// once for the front and once for the back side of the plane
1414	IncPvs(*ray->intersections[0].mObject, frontPvs, backPvs,
1415	cf, frontId, backId, frontAndBackId);
1416	}
1417
1418	// the source object in the origin of the ray
1419	if (ray->sourceObject.mObject)
1420	{
1421	IncPvs(*ray->sourceObject.mObject, frontPvs, backPvs,
1422	cf, frontId, backId, frontAndBackId);
1423	}
1424
1425	if (!sPvsUseArea) // use front and back cell areas to approximate volume
1426	{
1427	float len = Distance(entP, extP);
1428	pOverall += len;
1429
1430	// use length of rays to approximate volume
1431	switch (cf)
1432	{
1433	case Ray::COINCIDENT:
1434	pBack += len;
1435	pFront += len;
1436	break;
1437	case Ray::BACK:
1438	pBack += len;
1439	break;
1440	case Ray::FRONT:
1441	pFront += len;
1442	break;
1443	case Ray::FRONT_BACK:
1444	{
1445	// find intersection of ray segment with plane
1446	const Vector3 extp = ray->Extrap(maxT);
1447	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1448
1449	const float newT = t * maxT;
1450	float newLen = Distance(ray->Extrap(newT), extp);
1451
1452	pFront += len - newLen;
1453	pBack += newLen;
1454	}
1455	break;
1456	case Ray::BACK_FRONT:
1457	{
1458	// find intersection of ray segment with plane
1459	const Vector3 extp = ray->Extrap(maxT);
1460	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1461
1462	const float newT = t * maxT;
1463	float newLen = Distance(ray->Extrap(newT), extp);
1464
1465	pFront += len;
1466	pBack += len - newLen;
1467	}
1468	break;
1469	default:
1470	Debug << "Should not come here" << endl;
1471	break;
1472	}
1473	}
1474	}
1475	}
1476
1477	if ((sSplitPlaneStrategy & LEAST_RAY_SPLITS) && !rays.empty())
1478	val += sLeastRaySplitsFactor * sumRaySplits / (float)rays.size();
1479
1480	if ((sSplitPlaneStrategy & BALANCED_RAYS) && !rays.empty())
1481	val += sBalancedRaysFactor * fabs(sumBalancedRays) / (float)rays.size();
1482
1483	if ((sSplitPlaneStrategy & PVS) && area && pvs)
1484	{
1485	val += sPvsFactor * (frontPvs * pFront + (backPvs * pBack)) /
1486	(pOverall * (float)pvs * 2);
1487
1488	// give penalty to unbalanced split
1489	if (0)
1490	if (((pFront * 0.2 + Limits::Small) > pBack) \|\| (pFront < (pBack * 0.2 + Limits::Small)))
1491	val += 0.5;
1492	}
1493
1494	#ifdef _DEBUG
1495	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1496	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1497	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1498	#endif
1499	return val;
1500	}
1501
1502	void BspTree::IncPvs(Intersectable &obj,
1503	int &frontPvs,
1504	int &backPvs,
1505	const int cf,
1506	const int frontId,
1507	const int backId,
1508	const int frontAndBackId) const
1509	{
1510	// TODO: does this really belong to no pvs?
1511	//if (cf == Ray::COINCIDENT) return;
1512
1513	if (cf == Ray::FRONT)
1514	{
1515	if ((obj.mMailbox != frontId) &&
1516	(obj.mMailbox != frontAndBackId))
1517	{
1518	++ frontPvs;
1519
1520	if (obj.mMailbox != backId)
1521	obj.mMailbox = frontId;
1522	else
1523	obj.mMailbox = frontAndBackId;
1524	}
1525	}
1526	else if (cf == Ray::BACK)
1527	{
1528	if ((obj.mMailbox != backId) &&
1529	(obj.mMailbox != frontAndBackId))
1530	{
1531	++ backPvs;
1532
1533	if (obj.mMailbox != frontId)
1534	obj.mMailbox = backId;
1535	else
1536	obj.mMailbox = frontAndBackId;
1537	}
1538	}
1539	// object belongs to both PVS
1540	else if ((cf == Ray::FRONT_BACK) \|\| (cf == Ray::BACK_FRONT) \|\|(cf == Ray::COINCIDENT))
1541	{
1542	if (obj.mMailbox != frontAndBackId)
1543	{
1544	if (obj.mMailbox != frontId)
1545	++ frontPvs;
1546	if (obj.mMailbox != backId)
1547	++ backPvs;
1548
1549	obj.mMailbox = frontAndBackId;
1550	}
1551	}
1552	}
1553
1554	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1555	BspTraversalData &data) const
1556	{
1557	float val = 0;
1558
1559	if (sSplitPlaneStrategy & VERTICAL_AXIS)
1560	{
1561	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1562	// we put a penalty on the dot product between the "tiny" vertical axis
1563	// and the split plane axis
1564	val += sVerticalSplitsFactor *
1565	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1566	}
1567
1568	// the following criteria loop over all polygons to find the cost value
1569	if ((sSplitPlaneStrategy & BALANCED_POLYS) \|\|
1570	(sSplitPlaneStrategy & LEAST_SPLITS) \|\|
1571	(sSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1572	(sSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1573	(sSplitPlaneStrategy & BLOCKED_RAYS))
1574	{
1575	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1576	}
1577
1578	// the following criteria loop over all rays to find the cost value
1579	if ((sSplitPlaneStrategy & BALANCED_RAYS) \|\|
1580	(sSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1581	(sSplitPlaneStrategy & PVS))
1582	{
1583	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1584	data.mArea, *data.mGeometry);
1585	}
1586
1587	// return linear combination of the sums
1588	return val;
1589	}
1590
1591	void BspTree::ParseEnvironment()
1592	{
1593	//-- parse bsp cell tree construction method
1594	char constructionMethodStr[60];
1595
1596	environment->GetStringValue("BspTree.Construction.input", constructionMethodStr);
1597
1598	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
1599
1600	if (strcmp(constructionMethodStr, "fromViewCells") == 0)
1601	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
1602	else if (strcmp(constructionMethodStr, "fromSceneGeometry") == 0)
1603	sConstructionMethod = FROM_SCENE_GEOMETRY;
1604	else if (strcmp(constructionMethodStr, "fromRays") == 0)
1605	sConstructionMethod = FROM_RAYS;
1606	else
1607	{
1608	cerr << "Wrong construction method " << constructionMethodStr << endl;
1609	exit(1);
1610	}
1611
1612	Debug << "Construction method: " << constructionMethodStr << endl;
1613
1614	//-- termination criteria for autopartition
1615	environment->GetIntValue("BspTree.Termination.maxDepth", sTermMaxDepth);
1616	environment->GetIntValue("BspTree.Termination.minPvs", sTermMinPvs);
1617	environment->GetIntValue("BspTree.Termination.maxPolygons", sTermMaxPolygons);
1618	environment->GetIntValue("BspTree.Termination.maxRays", sTermMaxRays);
1619	environment->GetFloatValue("BspTree.Termination.minArea", sTermMinArea);
1620	environment->GetFloatValue("BspTree.Termination.maxRayContribution", sTermMaxRayContribution);
1621	environment->GetFloatValue("BspTree.Termination.maxAccRayLenght", sTermMaxAccRayLength);
1622
1623	//-- termination criteria for axis aligned split
1624	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", sCt_div_ci);
1625	environment->GetFloatValue("BspTree.Termination.AxisAligned.maxCostRatio", sMaxCostRatio);
1626	environment->GetIntValue("BspTree.Termination.AxisAligned.maxPolys",
1627	sTermMaxPolysForAxisAligned);
1628	environment->GetIntValue("BspTree.Termination.AxisAligned.maxRays",
1629	sTermMaxRaysForAxisAligned);
1630	environment->GetIntValue("BspTree.Termination.AxisAligned.maxObjects",
1631	sTermMaxObjectsForAxisAligned);
1632	//-- partition criteria
1633	environment->GetIntValue("BspTree.maxPolyCandidates", sMaxPolyCandidates);
1634	environment->GetIntValue("BspTree.maxRayCandidates", sMaxRayCandidates);
1635	environment->GetIntValue("BspTree.splitPlaneStrategy", sSplitPlaneStrategy);
1636	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", sSplitBorder);
1637
1638	environment->GetFloatValue("BspTree.Construction.sideTolerance", Vector3::sDistTolerance);
1639	Vector3::sDistToleranceSqrt = Vector3::sDistTolerance * Vector3::sDistTolerance;
1640
1641	// post processing stuff
1642	environment->GetIntValue("ViewCells.PostProcessing.minPvsDif", sMinPvsDif);
1643	environment->GetIntValue("ViewCells.PostProcessing.minPvs", sMinPvs);
1644	environment->GetIntValue("ViewCells.PostProcessing.maxPvs", sMaxPvs);
1645
1646	Debug << "BSP max depth: " << sTermMaxDepth << endl;
1647	Debug << "BSP min PVS: " << sTermMinPvs << endl;
1648	Debug << "BSP min area: " << sTermMinArea << endl;
1649	Debug << "BSP max polys: " << sTermMaxPolygons << endl;
1650	Debug << "BSP max rays: " << sTermMaxRays << endl;
1651	Debug << "BSP max polygon candidates: " << sMaxPolyCandidates << endl;
1652	Debug << "BSP max plane candidates: " << sMaxRayCandidates << endl;
1653
1654	Debug << "Split plane strategy: ";
1655	if (sSplitPlaneStrategy & RANDOM_POLYGON)
1656	Debug << "random polygon ";
1657	if (sSplitPlaneStrategy & AXIS_ALIGNED)
1658	Debug << "axis aligned ";
1659	if (sSplitPlaneStrategy & LEAST_SPLITS)
1660	Debug << "least splits ";
1661	if (sSplitPlaneStrategy & BALANCED_POLYS)
1662	Debug << "balanced polygons ";
1663	if (sSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1664	Debug << "balanced view cells ";
1665	if (sSplitPlaneStrategy & LARGEST_POLY_AREA)
1666	Debug << "largest polygon area ";
1667	if (sSplitPlaneStrategy & VERTICAL_AXIS)
1668	Debug << "vertical axis ";
1669	if (sSplitPlaneStrategy & BLOCKED_RAYS)
1670	Debug << "blocked rays ";
1671	if (sSplitPlaneStrategy & LEAST_RAY_SPLITS)
1672	Debug << "least ray splits ";
1673	if (sSplitPlaneStrategy & BALANCED_RAYS)
1674	Debug << "balanced rays ";
1675	if (sSplitPlaneStrategy & PVS)
1676	Debug << "pvs";
1677	Debug << endl;
1678	}
1679
1680	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1681	{
1682	stack<BspNode *> nodeStack;
1683	nodeStack.push(mRoot);
1684
1685	while (!nodeStack.empty())
1686	{
1687	BspNode *node = nodeStack.top();
1688
1689	nodeStack.pop();
1690
1691	if (node->IsLeaf())
1692	{
1693	BspLeaf leaf = (BspLeaf )node;
1694	leaves.push_back(leaf);
1695	}
1696	else
1697	{
1698	BspInterior interior = dynamic_cast<BspInterior >(node);
1699
1700	nodeStack.push(interior->GetBack());
1701	nodeStack.push(interior->GetFront());
1702	}
1703	}
1704	}
1705
1706	AxisAlignedBox3 BspTree::GetBoundingBox() const
1707	{
1708	return mBox;
1709	}
1710
1711	BspNode *BspTree::GetRoot() const
1712	{
1713	return mRoot;
1714	}
1715
1716	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1717	{
1718	// the node became a leaf -> evaluate stats for leafs
1719	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1720
1721	if (data.mDepth >= sTermMaxDepth)
1722	++ mStat.maxDepthNodes;
1723
1724	// store maximal and minimal depth
1725	if (data.mDepth > mStat.maxDepth)
1726	mStat.maxDepth = data.mDepth;
1727
1728	if (data.mDepth < mStat.minDepth)
1729	mStat.minDepth = data.mDepth;
1730
1731	// accumulate depth to compute average depth
1732	mStat.accumDepth += data.mDepth;
1733
1734	#ifdef _DEBUG
1735	Debug << "BSP stats: "
1736	<< "Depth: " << data.mDepth << " (max: " << sTermMaxDepth << "), "
1737	<< "PVS: " << data.mPvs << " (min: " << sTermMinPvs << "), "
1738	<< "Area: " << data.mArea << " (min: " << sTermMinArea << "), "
1739	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << sTermMaxPolygons << "), "
1740	<< "#rays: " << (int)data.mRays->size() << " (max: " << sTermMaxRays << "), "
1741	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1742	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1743	#endif
1744	}
1745
1746	int BspTree::CastRay(Ray &ray)
1747	{
1748	int hits = 0;
1749
1750	stack<BspRayTraversalData> tStack;
1751
1752	float maxt, mint;
1753
1754	if (!BoundRay(ray, mint, maxt))
1755	return 0;
1756
1757	Intersectable::NewMail();
1758
1759	Vector3 entp = ray.Extrap(mint);
1760	Vector3 extp = ray.Extrap(maxt);
1761
1762	BspNode *node = mRoot;
1763	BspNode *farChild = NULL;
1764
1765	while (1)
1766	{
1767	if (!node->IsLeaf())
1768	{
1769	BspInterior in = (BspInterior ) node;
1770
1771	Plane3 *splitPlane = in->GetPlane();
1772
1773	int entSide = splitPlane->Side(entp);
1774	int extSide = splitPlane->Side(extp);
1775
1776	Vector3 intersection;
1777
1778	if (entSide < 0)
1779	{
1780	node = in->GetBack();
1781
1782	if(extSide <= 0) // plane does not split ray => no far child
1783	continue;
1784
1785	farChild = in->GetFront(); // plane splits ray
1786
1787	} else if (entSide > 0)
1788	{
1789	node = in->GetFront();
1790
1791	if (extSide >= 0) // plane does not split ray => no far child
1792	continue;
1793
1794	farChild = in->GetBack(); // plane splits ray
1795	}
1796	else // ray and plane are coincident
1797	// WHAT TO DO IN THIS CASE ?
1798	{
1799	break;
1800	//node = in->GetFront();
1801	//continue;
1802	}
1803
1804	// push data for far child
1805	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1806
1807	// find intersection of ray segment with plane
1808	float t;
1809	extp = splitPlane->FindIntersection(ray.GetLoc(), extp, &t);
1810	maxt *= t;
1811
1812	} else // reached leaf => intersection with view cell
1813	{
1814	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1815
1816	if (!leaf->mViewCell->Mailed())
1817	{
1818	ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1819	leaf->mViewCell->Mail();
1820	++ hits;
1821	}
1822
1823	//-- fetch the next far child from the stack
1824	if (tStack.empty())
1825	break;
1826
1827	entp = extp;
1828	mint = maxt; // NOTE: need this?
1829
1830	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1831	break;
1832
1833	BspRayTraversalData &s = tStack.top();
1834
1835	node = s.mNode;
1836	extp = s.mExitPoint;
1837	maxt = s.mMaxT;
1838
1839	tStack.pop();
1840	}
1841	}
1842
1843	return hits;
1844	}
1845
1846	bool BspTree::Export(const string filename)
1847	{
1848	Exporter *exporter = Exporter::GetExporter(filename);
1849
1850	if (exporter)
1851	{
1852	exporter->ExportBspTree(*this);
1853	return true;
1854	}
1855
1856	return false;
1857	}
1858
1859	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
1860	{
1861	stack<BspNode *> nodeStack;
1862	nodeStack.push(mRoot);
1863
1864	ViewCell::NewMail();
1865
1866	while (!nodeStack.empty())
1867	{
1868	BspNode *node = nodeStack.top();
1869	nodeStack.pop();
1870
1871	if (node->IsLeaf())
1872	{
1873	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1874
1875	if (!viewCell->Mailed())
1876	{
1877	viewCell->Mail();
1878	viewCells.push_back(viewCell);
1879	}
1880	}
1881	else
1882	{
1883	BspInterior interior = dynamic_cast<BspInterior >(node);
1884
1885	nodeStack.push(interior->mFront);
1886	nodeStack.push(interior->mBack);
1887	}
1888	}
1889	}
1890
1891	void BspTree::EvaluateViewCellsStats(BspViewCellsStatistics &stat) const
1892	{
1893	stat.Reset();
1894
1895	stack<BspNode *> nodeStack;
1896	nodeStack.push(mRoot);
1897
1898	ViewCell::NewMail();
1899
1900	// exclude root cell
1901	mRootCell->Mail();
1902
1903	while (!nodeStack.empty())
1904	{
1905	BspNode *node = nodeStack.top();
1906	nodeStack.pop();
1907
1908	if (node->IsLeaf())
1909	{
1910	++ stat.bspLeaves;
1911
1912	BspViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1913
1914	if (!viewCell->Mailed())
1915	{
1916	viewCell->Mail();
1917
1918	++ stat.viewCells;
1919	const int pvsSize = viewCell->GetPvs().GetSize();
1920
1921	stat.pvs += pvsSize;
1922
1923	if (pvsSize < 1)
1924	++ stat.emptyPvs;
1925
1926	if (pvsSize > stat.maxPvs)
1927	stat.maxPvs = pvsSize;
1928
1929	if (pvsSize < stat.minPvs)
1930	stat.minPvs = pvsSize;
1931
1932	if ((int)viewCell->mBspLeaves.size() > stat.maxBspLeaves)
1933	stat.maxBspLeaves = (int)viewCell->mBspLeaves.size();
1934	}
1935	}
1936	else
1937	{
1938	BspInterior interior = dynamic_cast<BspInterior >(node);
1939
1940	nodeStack.push(interior->mFront);
1941	nodeStack.push(interior->mBack);
1942	}
1943	}
1944	}
1945
1946	bool BspTree::MergeViewCells(BspLeaf front, BspLeaf back) const
1947	{
1948	BspViewCell *viewCell =
1949	dynamic_cast<BspViewCell >(ViewCell::Merge(front->mViewCell, *back->mViewCell));
1950
1951	if (!viewCell)
1952	return false;
1953
1954	// change view cells of all leaves associated with the
1955	// previous view cells
1956
1957	BspViewCell *fVc = front->mViewCell;
1958	BspViewCell *bVc = back->mViewCell;
1959
1960	vector<BspLeaf *> fLeaves = fVc->mBspLeaves;
1961	vector<BspLeaf *> bLeaves = bVc->mBspLeaves;
1962
1963	vector<BspLeaf *>::const_iterator it;
1964
1965	for (it = fLeaves.begin(); it != fLeaves.end(); ++ it)
1966	{
1967	(*it)->SetViewCell(viewCell);
1968	viewCell->mBspLeaves.push_back(*it);
1969	}
1970	for (it = bLeaves.begin(); it != bLeaves.end(); ++ it)
1971	{
1972	(*it)->SetViewCell(viewCell);
1973	viewCell->mBspLeaves.push_back(*it);
1974	}
1975
1976	DEL_PTR(fVc);
1977	DEL_PTR(bVc);
1978
1979	return true;
1980	}
1981
1982	bool BspTree::ShouldMerge(BspLeaf front, BspLeaf back) const
1983	{
1984	ViewCell *fvc = front->mViewCell;
1985	ViewCell *bvc = back->mViewCell;
1986
1987	if ((fvc == mRootCell) \|\| (bvc == mRootCell) \|\| (fvc == bvc))
1988	return false;
1989
1990	int fdiff = fvc->GetPvs().Diff(bvc->GetPvs());
1991
1992	if (fvc->GetPvs().GetSize() + fdiff < sMaxPvs)
1993	{
1994	if ((fvc->GetPvs().GetSize() < sMinPvs) \|\|
1995	(bvc->GetPvs().GetSize() < sMinPvs) \|\|
1996	((fdiff < sMinPvsDif) && (bvc->GetPvs().Diff(fvc->GetPvs()) < sMinPvsDif)))
1997	{
1998	return true;
1999	}
2000	}
2001
2002	return false;
2003	}
2004
2005	void BspTree::SetGenerateViewCells(int generateViewCells)
2006	{
2007	mGenerateViewCells = generateViewCells;
2008	}
2009
2010	BspTreeStatistics &BspTree::GetStat()
2011	{
2012	return mStat;
2013	}
2014
2015	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2016	{
2017	float len = 0;
2018
2019	BoundedRayContainer::const_iterator it, it_end = rays.end();
2020
2021	for (it = rays.begin(); it != it_end; ++ it)
2022	{
2023	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2024	(it)->mRay->Extrap((it)->mMaxT));
2025	}
2026
2027	return len;
2028	}
2029
2030	int BspTree::SplitRays(const Plane3 &plane,
2031	BoundedRayContainer &rays,
2032	BoundedRayContainer &frontRays,
2033	BoundedRayContainer &backRays)
2034	{
2035	int splits = 0;
2036
2037	while (!rays.empty())
2038	{
2039	BoundedRay *bRay = rays.back();
2040	Ray *ray = bRay->mRay;
2041	float minT = bRay->mMinT;
2042	float maxT = bRay->mMaxT;
2043
2044	rays.pop_back();
2045
2046	Vector3 entP, extP;
2047
2048	const int cf =
2049	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2050
2051	// set id to ray classification
2052	ray->SetId(cf);
2053
2054	switch (cf)
2055	{
2056	case Ray::COINCIDENT: // TODO: should really discard ray?
2057	//frontRays.push_back(bRay);
2058	DEL_PTR(bRay);
2059	break;
2060	case Ray::BACK:
2061	backRays.push_back(bRay);
2062	break;
2063	case Ray::FRONT:
2064	frontRays.push_back(bRay);
2065	break;
2066	case Ray::FRONT_BACK:
2067	{
2068	// find intersection of ray segment with plane
2069	const float t = plane.FindT(ray->GetLoc(), extP);
2070
2071	const float newT = t * maxT;
2072
2073	frontRays.push_back(new BoundedRay(ray, minT, newT));
2074	backRays.push_back(new BoundedRay(ray, newT, maxT));
2075
2076	DEL_PTR(bRay);
2077	}
2078	break;
2079	case Ray::BACK_FRONT:
2080	{
2081	// find intersection of ray segment with plane
2082	const float t = plane.FindT(ray->GetLoc(), extP);
2083	const float newT = t * bRay->mMaxT;
2084
2085	backRays.push_back(new BoundedRay(ray, bRay->mMinT, newT));
2086	frontRays.push_back(new BoundedRay(ray, newT, bRay->mMaxT));
2087	DEL_PTR(bRay);
2088
2089	++ splits;
2090	}
2091	break;
2092	default:
2093	Debug << "Should not come here" << endl;
2094	break;
2095	}
2096	}
2097
2098	return splits;
2099	}
2100
2101	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2102	{
2103	BspNode *lastNode;
2104	do
2105	{
2106	lastNode = n;
2107
2108	// want to get planes defining geometry of this node => don't take
2109	// split plane of node itself
2110	n = n->GetParent();
2111
2112	if (n)
2113	{
2114	BspInterior interior = dynamic_cast<BspInterior >(n);
2115	Plane3 halfSpace = dynamic_cast<BspInterior >(interior)->GetPlane();
2116
2117	if (interior->mFront != lastNode)
2118	halfSpace.ReverseOrientation();
2119
2120	halfSpaces.push_back(halfSpace);
2121	}
2122	}
2123	while (n);
2124	}
2125
2126	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &cell) const
2127	{
2128	PolygonContainer polys;
2129	ConstructGeometry(n, polys);
2130	cell.mPolys = polys;
2131	}
2132
2133	void BspTree::ConstructGeometry(BspViewCell *vc, PolygonContainer &cell) const
2134	{
2135	vector<BspLeaf *> leaves = vc->mBspLeaves;
2136
2137	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2138
2139	for (it = leaves.begin(); it != it_end; ++ it)
2140	ConstructGeometry(*it, cell);
2141	}
2142
2143
2144	void BspTree::ConstructGeometry(BspNode *n, PolygonContainer &cell) const
2145	{
2146	vector<Plane3> halfSpaces;
2147	ExtractHalfSpaces(n, halfSpaces);
2148
2149	PolygonContainer candidatePolys;
2150
2151	// bounded planes are added to the polygons (reverse polygons
2152	// as they have to be outfacing
2153	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2154	{
2155	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2156
2157	if (p->Valid())
2158	{
2159	candidatePolys.push_back(p->CreateReversePolygon());
2160	DEL_PTR(p);
2161	}
2162	}
2163
2164	// add faces of bounding box (also could be faces of the cell)
2165	for (int i = 0; i < 6; ++ i)
2166	{
2167	VertexContainer vertices;
2168
2169	for (int j = 0; j < 4; ++ j)
2170	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2171
2172	candidatePolys.push_back(new Polygon3(vertices));
2173	}
2174
2175	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2176	{
2177	// polygon is split by all other planes
2178	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2179	{
2180	if (i == j) // polygon and plane are coincident
2181	continue;
2182
2183	VertexContainer splitPts;
2184	Polygon3 frontPoly, backPoly;
2185
2186	const int cf = candidatePolys[i]->ClassifyPlane(halfSpaces[j]);
2187
2188	switch (cf)
2189	{
2190	case Polygon3::SPLIT:
2191	frontPoly = new Polygon3();
2192	backPoly = new Polygon3();
2193
2194	candidatePolys[i]->Split(halfSpaces[j], *frontPoly,
2195	*backPoly, splitPts);
2196
2197	DEL_PTR(candidatePolys[i]);
2198
2199	if (frontPoly->Valid())
2200	candidatePolys[i] = frontPoly;
2201	else
2202	DEL_PTR(frontPoly);
2203
2204	DEL_PTR(backPoly);
2205	break;
2206	case Polygon3::BACK_SIDE:
2207	DEL_PTR(candidatePolys[i]);
2208	break;
2209	// just take polygon as it is
2210	case Polygon3::FRONT_SIDE:
2211	case Polygon3::COINCIDENT:
2212	default:
2213	break;
2214	}
2215	}
2216
2217	if (candidatePolys[i])
2218	cell.push_back(candidatePolys[i]);
2219	}
2220	}
2221
2222
2223	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2224	const bool onlyUnmailed) const
2225	{
2226	PolygonContainer cell;
2227
2228	ConstructGeometry(n, cell);
2229
2230	stack<BspNode *> nodeStack;
2231	nodeStack.push(mRoot);
2232
2233	// planes needed to verify that we found neighbor leaf.
2234	vector<Plane3> halfSpaces;
2235	ExtractHalfSpaces(n, halfSpaces);
2236
2237	while (!nodeStack.empty())
2238	{
2239	BspNode *node = nodeStack.top();
2240	nodeStack.pop();
2241
2242	if (node->IsLeaf())
2243	{
2244	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2245	{
2246	// test all planes of current node if candidate really
2247	// is neighbour
2248	PolygonContainer neighborCandidate;
2249	ConstructGeometry(node, neighborCandidate);
2250
2251	bool isAdjacent = true;
2252	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2253	{
2254	const int cf =
2255	Polygon3::ClassifyPlane(neighborCandidate, halfSpaces[i]);
2256
2257	if (cf == Polygon3::BACK_SIDE)
2258	isAdjacent = false;
2259	}
2260
2261	if (isAdjacent)
2262	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2263
2264	CLEAR_CONTAINER(neighborCandidate);
2265	}
2266	}
2267	else
2268	{
2269	BspInterior interior = dynamic_cast<BspInterior >(node);
2270
2271	const int cf = Polygon3::ClassifyPlane(cell, interior->mPlane);
2272
2273	if (cf == Polygon3::FRONT_SIDE)
2274	nodeStack.push(interior->mFront);
2275	else
2276	if (cf == Polygon3::BACK_SIDE)
2277	nodeStack.push(interior->mBack);
2278	else
2279	{
2280	// random decision
2281	nodeStack.push(interior->mBack);
2282	nodeStack.push(interior->mFront);
2283	}
2284	}
2285	}
2286
2287	CLEAR_CONTAINER(cell);
2288	return (int)neighbors.size();
2289	}
2290
2291	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2292	{
2293	stack<BspNode *> nodeStack;
2294	nodeStack.push(mRoot);
2295
2296	int mask = rand();
2297
2298	while (!nodeStack.empty())
2299	{
2300	BspNode *node = nodeStack.top();
2301	nodeStack.pop();
2302
2303	if (node->IsLeaf())
2304	{
2305	return dynamic_cast<BspLeaf *>(node);
2306	}
2307	else
2308	{
2309	BspInterior interior = dynamic_cast<BspInterior >(node);
2310
2311	BspNode *next;
2312
2313	PolygonContainer cell;
2314
2315	// todo: not very efficient: constructs full cell everytime
2316	ConstructGeometry(interior, cell);
2317
2318	const int cf = Polygon3::ClassifyPlane(cell, halfspace);
2319
2320	if (cf == Polygon3::BACK_SIDE)
2321	next = interior->mFront;
2322	else
2323	if (cf == Polygon3::FRONT_SIDE)
2324	next = interior->mFront;
2325	else
2326	{
2327	// random decision
2328	if (mask & 1)
2329	next = interior->mBack;
2330	else
2331	next = interior->mFront;
2332	mask = mask >> 1;
2333	}
2334
2335	nodeStack.push(next);
2336	}
2337	}
2338
2339	return NULL;
2340	}
2341
2342	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2343	{
2344	stack<BspNode *> nodeStack;
2345
2346	nodeStack.push(mRoot);
2347
2348	int mask = rand();
2349
2350	while (!nodeStack.empty())
2351	{
2352	BspNode *node = nodeStack.top();
2353	nodeStack.pop();
2354
2355	if (node->IsLeaf())
2356	{
2357	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2358	return dynamic_cast<BspLeaf *>(node);
2359	}
2360	else
2361	{
2362	BspInterior interior = dynamic_cast<BspInterior >(node);
2363
2364	// random decision
2365	if (mask & 1)
2366	nodeStack.push(interior->mBack);
2367	else
2368	nodeStack.push(interior->mFront);
2369
2370	mask = mask >> 1;
2371	}
2372	}
2373
2374	return NULL;
2375	}
2376
2377	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2378	{
2379	int pvsSize = 0;
2380
2381	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2382
2383	Intersectable::NewMail();
2384
2385	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2386	{
2387	Ray ray = (rit)->mRay;
2388
2389	if (!ray->intersections.empty())
2390	{
2391	if (!ray->intersections[0].mObject->Mailed())
2392	{
2393	ray->intersections[0].mObject->Mail();
2394	++ pvsSize;
2395	}
2396	}
2397	if (ray->sourceObject.mObject)
2398	{
2399	if (!ray->sourceObject.mObject->Mailed())
2400	{
2401	ray->sourceObject.mObject->Mail();
2402	++ pvsSize;
2403	}
2404	}
2405	}
2406
2407	return pvsSize;
2408	}
2409
2410	/*************************************************************
2411	* BspNodeGeometry Implementation *
2412	*************************************************************/
2413
2414	BspNodeGeometry::~BspNodeGeometry()
2415	{
2416	CLEAR_CONTAINER(mPolys);
2417	}
2418
2419	float BspNodeGeometry::GetArea() const
2420	{
2421	return Polygon3::GetArea(mPolys);
2422	}
2423
2424	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2425	BspNodeGeometry &back,
2426	const BspTree &tree,
2427	const Plane3 &splitPlane) const
2428	{
2429	// get cross section of new polygon
2430	Polygon3 *planePoly = tree.GetBoundingBox().CrossSection(splitPlane);
2431
2432	planePoly = SplitPolygon(planePoly, tree);
2433
2434	//-- plane poly splits all other cell polygons
2435	for (int i = 0; i < (int)mPolys.size(); ++ i)
2436	{
2437	const int cf = mPolys[i]->ClassifyPlane(splitPlane, 0.00001f);
2438
2439	// split new polygon with all previous planes
2440	switch (cf)
2441	{
2442	case Polygon3::SPLIT:
2443	{
2444	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2445
2446	Polygon3 *frontPoly = new Polygon3();
2447	Polygon3 *backPoly = new Polygon3();
2448
2449	VertexContainer splitPts;
2450
2451	poly->Split(splitPlane, frontPoly, backPoly, splitPts);
2452
2453	DEL_PTR(poly);
2454
2455	if (frontPoly->Valid())
2456	front.mPolys.push_back(frontPoly);
2457	if (backPoly->Valid())
2458	back.mPolys.push_back(backPoly);
2459	}
2460
2461	break;
2462	case Polygon3::BACK_SIDE:
2463	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2464	break;
2465	case Polygon3::FRONT_SIDE:
2466	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2467	break;
2468	case Polygon3::COINCIDENT:
2469	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2470	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2471	break;
2472	default:
2473	break;
2474	}
2475	}
2476
2477	//-- finally add the new polygon to the child cells
2478	if (planePoly)
2479	{
2480	// add polygon with normal pointing into positive half space to back cell
2481	back.mPolys.push_back(planePoly);
2482	// add polygon with reverse orientation to front cell
2483	front.mPolys.push_back(planePoly->CreateReversePolygon());
2484	}
2485
2486	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2487	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2488	}
2489
2490	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2491	const BspTree &tree) const
2492	{
2493	// polygon is split by all other planes
2494	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2495	{
2496	Plane3 plane = mPolys[i]->GetSupportingPlane();
2497
2498	const int cf =
2499	planePoly->ClassifyPlane(plane, 0.00001f);
2500
2501	// split new polygon with all previous planes
2502	switch (cf)
2503	{
2504	case Polygon3::SPLIT:
2505	{
2506	VertexContainer splitPts;
2507
2508	Polygon3 *frontPoly = new Polygon3();
2509	Polygon3 *backPoly = new Polygon3();
2510
2511	planePoly->Split(plane, frontPoly, backPoly, splitPts);
2512	DEL_PTR(planePoly);
2513
2514	if (backPoly->Valid())
2515	planePoly = backPoly;
2516	else
2517	DEL_PTR(backPoly);
2518	}
2519	break;
2520	case Polygon3::FRONT_SIDE:
2521	DEL_PTR(planePoly);
2522	break;
2523	// polygon is taken as it is
2524	case Polygon3::BACK_SIDE:
2525	case Polygon3::COINCIDENT:
2526	default:
2527	break;
2528	}
2529	}
2530
2531	return planePoly;
2532	}
2533
2534	void BspViewCellsStatistics::Print(ostream &app) const
2535	{
2536	app << "===== BspViewCells statistics ===============\n";
2537
2538	app << setprecision(4);
2539
2540	//app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
2541
2542	app << "#N_OVERALLPVS ( objects in PVS )\n" << pvs << endl;
2543
2544	app << "#N_PMAXPVS ( largest PVS )\n" << maxPvs << endl;
2545
2546	app << "#N_PMINPVS ( smallest PVS )\n" << minPvs << endl;
2547
2548	app << "#N_PAVGPVS ( average PVS )\n" << AvgPvs() << endl;
2549
2550	app << "#N_PEMPTYPVS ( view cells with PVS smaller 2 )\n" << emptyPvs << endl;
2551
2552	app << "#N_VIEWCELLS ( number of view cells)\n" << viewCells << endl;
2553
2554	app << "#N_AVGBSPLEAVES (average number of BSP leaves per view cell )\n" << AvgBspLeaves() << endl;
2555
2556	app << "#N_MAXBSPLEAVES ( maximal number of BSP leaves per view cell )\n" << maxBspLeaves << endl;
2557
2558	app << "===== END OF BspViewCells statistics ==========\n";
2559	}

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