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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 650

Revision 650, 77.1 KB checked in by mattausch, 18 years ago (diff)
added spatial hierarchy based merge tree

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	/* class BspLeaf implementation */
164	/****************************************************************/
165
166
167	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
168	{
169	}
170
171
172	BspLeaf::~BspLeaf()
173	{
174	DEL_PTR(mPvs);
175	}
176
177
178	BspLeaf::BspLeaf(ViewCell *viewCell):
179	mViewCell(viewCell)
180	{
181	}
182
183
184	BspLeaf::BspLeaf(BspInterior *parent):
185	BspNode(parent), mViewCell(NULL), mPvs(NULL)
186	{}
187
188
189
190	BspLeaf::BspLeaf(BspInterior parent, ViewCell viewCell):
191	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
192	{
193	}
194
195	ViewCell *BspLeaf::GetViewCell() const
196	{
197	return mViewCell;
198	}
199
200	void BspLeaf::SetViewCell(ViewCell *viewCell)
201	{
202	mViewCell = viewCell;
203	}
204
205
206	bool BspLeaf::IsLeaf() const
207	{
208	return true;
209	}
210
211
212	/*********************************************************************/
213	/* class BspTree implementation */
214	/*********************************************************************/
215
216	BspTree::BspTree():
217	mRoot(NULL),
218	mUseAreaForPvs(false),
219	mGenerateViewCells(true),
220	mTimeStamp(1)
221	{
222	Randomize(); // initialise random generator for heuristics
223
224	mOutOfBoundsCell = GetOrCreateOutOfBoundsCell();
225
226	//-- termination criteria for autopartition
227	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
228	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
229	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
230	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
231	environment->GetFloatValue("BspTree.Termination.minProbability", mTermMinProbability);
232	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
233	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
234
235	//-- factors for bsp tree split plane heuristics
236	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
237	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
238	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
239	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
240	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
241	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
242	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
243	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
244	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
245	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
246
247	//-- termination criteria for axis aligned split
248	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
249	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
250	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
251	mTermMinPolysForAxisAligned);
252	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
253	mTermMinRaysForAxisAligned);
254	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
255	mTermMinObjectsForAxisAligned);
256	//-- partition criteria
257	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
258	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
259	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
260	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
261	environment->GetIntValue("BspTree.maxTests", mMaxTests);
262	environment->GetIntValue("BspTree.Termination.maxViewCells", mMaxViewCells);
263
264	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
265
266	mSubdivisionStats.open("subdivisionStats.log");
267
268	Debug << "BSP max depth: " << mTermMaxDepth << endl;
269	Debug << "BSP min PVS: " << mTermMinPvs << endl;
270	Debug << "BSP min probability: " << mTermMinProbability << endl;
271	Debug << "BSP max polys: " << mTermMinPolys << endl;
272	Debug << "BSP max rays: " << mTermMinRays << endl;
273	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
274	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
275
276	Debug << "Split plane strategy: ";
277	if (mSplitPlaneStrategy & RANDOM_POLYGON)
278	Debug << "random polygon ";
279	if (mSplitPlaneStrategy & AXIS_ALIGNED)
280	Debug << "axis aligned ";
281	if (mSplitPlaneStrategy & LEAST_SPLITS)
282	Debug << "least splits ";
283	if (mSplitPlaneStrategy & BALANCED_POLYS)
284	Debug << "balanced polygons ";
285	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
286	Debug << "balanced view cells ";
287	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
288	Debug << "largest polygon area ";
289	if (mSplitPlaneStrategy & VERTICAL_AXIS)
290	Debug << "vertical axis ";
291	if (mSplitPlaneStrategy & BLOCKED_RAYS)
292	Debug << "blocked rays ";
293	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
294	Debug << "least ray splits ";
295	if (mSplitPlaneStrategy & BALANCED_RAYS)
296	Debug << "balanced rays ";
297	if (mSplitPlaneStrategy & PVS)
298	Debug << "pvs";
299
300	Debug << endl;
301	}
302
303
304	const BspTreeStatistics &BspTree::GetStatistics() const
305	{
306	return mStat;
307	}
308
309
310	int BspTree::SplitPolygons(const Plane3 &plane,
311	PolygonContainer &polys,
312	PolygonContainer &frontPolys,
313	PolygonContainer &backPolys,
314	PolygonContainer &coincident) const
315	{
316	int splits = 0;
317
318	#ifdef _Debug
319	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
320	#endif
321
322	PolygonContainer::const_iterator it, it_end = polys.end();
323
324	for (it = polys.begin(); it != polys.end(); ++ it)
325	{
326	Polygon3 poly = it;
327
328	//-- classify polygon
329	const int cf = poly->ClassifyPlane(plane, mEpsilon);
330
331	switch (cf)
332	{
333	case Polygon3::COINCIDENT:
334	coincident.push_back(poly);
335	break;
336	case Polygon3::FRONT_SIDE:
337	frontPolys.push_back(poly);
338	break;
339	case Polygon3::BACK_SIDE:
340	backPolys.push_back(poly);
341	break;
342	case Polygon3::SPLIT:
343	{
344	Polygon3 *front_piece = new Polygon3(poly->mParent);
345	Polygon3 *back_piece = new Polygon3(poly->mParent);
346
347	//-- split polygon into front and back part
348	poly->Split(plane,
349	*front_piece,
350	*back_piece,
351	mEpsilon);
352
353	++ splits; // increase number of splits
354
355	//-- inherit rays from parent polygon for blocked ray criterium
356	poly->InheritRays(front_piece, back_piece);
357
358	// check if polygons still valid
359	if (front_piece->Valid(mEpsilon))
360	frontPolys.push_back(front_piece);
361	else
362	DEL_PTR(front_piece);
363
364	if (back_piece->Valid(mEpsilon))
365	backPolys.push_back(back_piece);
366	else
367	DEL_PTR(back_piece);
368
369	#ifdef _DEBUG
370	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
371	#endif
372	DEL_PTR(poly);
373	}
374	break;
375	default:
376	Debug << "SHOULD NEVER COME HERE\n";
377	break;
378	}
379	}
380
381	return splits;
382	}
383
384
385	void BspTreeStatistics::Print(ostream &app) const
386	{
387	app << "===== BspTree statistics ===============\n";
388
389	app << setprecision(4);
390
391	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
392
393	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
394
395	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
396
397	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
398
399	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
400
401	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
402
403	app << "#N_SPLITS ( Number of splits in axes x y z\n";
404
405	for (int i = 0; i < 3; ++ i)
406	app << splits[i] << " ";
407	app << endl;
408
409	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
410	<< maxDepthNodes * 100 / (double)Leaves() << endl;
411
412	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
413	<< minPvsNodes * 100 / (double)Leaves() << endl;
414
415	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
416	<< minRaysNodes * 100 / (double)Leaves() << endl;
417
418	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
419	<< maxCostNodes * 100 / (double)Leaves() << endl;
420
421	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
422	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
423
424	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
425	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
426
427	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
428
429	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
430
431	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
432
433	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
434
435	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
436
437	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
438	//app << "#N_PVS: " << pvs << endl;
439
440	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
441	(polys + polySplits) / (double)polys << endl;
442
443	app << "===== END OF BspTree statistics ==========\n";
444	}
445
446
447	BspTree::~BspTree()
448	{
449	DEL_PTR(mRoot);
450
451	// TODO must be deleted if used!!
452	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
453	}
454
455	BspViewCell *BspTree::GetOutOfBoundsCell()
456	{
457	return mOutOfBoundsCell;
458	}
459
460
461	BspNode *BspTree::GetRoot() const
462	{
463	return mRoot;
464	}
465
466	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
467	{
468	if (!mOutOfBoundsCell)
469	{
470	mOutOfBoundsCell = new BspViewCell();
471	mOutOfBoundsCell->SetId(-1);
472	mOutOfBoundsCell->SetValid(false);
473	}
474
475	return mOutOfBoundsCell;
476	}
477
478
479	void BspTree::InsertViewCell(ViewCell *viewCell)
480	{
481	PolygonContainer *polys = new PolygonContainer();
482
483	// don't generate new view cell, insert this one
484	mGenerateViewCells = false;
485	// extract polygons that guide the split process
486	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
487	mBox.Include(viewCell->GetBox()); // add to BSP aabb
488
489	InsertPolygons(polys);
490	}
491
492
493	void BspTree::InsertPolygons(PolygonContainer *polys)
494	{
495	BspTraversalStack tStack;
496
497	// traverse existing tree or create new tree
498	if (!mRoot)
499	mRoot = new BspLeaf();
500
501	tStack.push(BspTraversalData(mRoot,
502	polys,
503	0,
504	mOutOfBoundsCell,
505	new BoundedRayContainer(),
506	0,
507	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
508	new BspNodeGeometry()));
509
510	while (!tStack.empty())
511	{
512	// filter polygons donw the tree
513	BspTraversalData tData = tStack.top();
514	tStack.pop();
515
516	if (!tData.mNode->IsLeaf())
517	{
518	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
519
520	//-- filter view cell polygons down the tree until a leaf is reached
521	if (!tData.mPolygons->empty())
522	{
523	PolygonContainer *frontPolys = new PolygonContainer();
524	PolygonContainer *backPolys = new PolygonContainer();
525	PolygonContainer coincident;
526
527	int splits = 0;
528
529	// split viewcell polygons with respect to split plane
530	splits += SplitPolygons(interior->GetPlane(),
531	*tData.mPolygons,
532	*frontPolys,
533	*backPolys,
534	coincident);
535
536	// extract view cells associated with the split polygons
537	ViewCell *frontViewCell = GetOrCreateOutOfBoundsCell();
538	ViewCell *backViewCell = GetOrCreateOutOfBoundsCell();
539
540	BspTraversalData frontData(interior->GetFront(),
541	frontPolys,
542	tData.mDepth + 1,
543	mOutOfBoundsCell,
544	tData.mRays,
545	tData.mPvs,
546	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
547	new BspNodeGeometry());
548
549	BspTraversalData backData(interior->GetBack(),
550	backPolys,
551	tData.mDepth + 1,
552	mOutOfBoundsCell,
553	tData.mRays,
554	tData.mPvs,
555	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
556	new BspNodeGeometry());
557
558	if (!mGenerateViewCells)
559	{
560	ExtractViewCells(frontData,
561	backData,
562	coincident,
563	interior->mPlane);
564	}
565
566	// don't need coincident polygons anymore
567	CLEAR_CONTAINER(coincident);
568
569	mStat.polySplits += splits;
570
571	// push the children on the stack
572	tStack.push(frontData);
573	tStack.push(backData);
574	}
575
576	// cleanup
577	DEL_PTR(tData.mPolygons);
578	DEL_PTR(tData.mRays);
579	}
580	else
581	{
582	// reached leaf => subdivide current viewcell
583	BspNode *subRoot = Subdivide(tStack, tData);
584	}
585	}
586	}
587
588	int BspTree::AddMeshToPolygons(Mesh *mesh,
589	PolygonContainer &polys,
590	MeshInstance *parent)
591	{
592	FaceContainer::const_iterator fi;
593
594	// copy the face data to polygons
595	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
596	{
597	Polygon3 poly = new Polygon3((fi), mesh);
598
599	if (poly->Valid(mEpsilon))
600	{
601	poly->mParent = parent; // set parent intersectable
602	polys.push_back(poly);
603	}
604	else
605	DEL_PTR(poly);
606	}
607	return (int)mesh->mFaces.size();
608	}
609
610
611	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
612	PolygonContainer &polys,
613	int maxObjects)
614	{
615	int limit = (maxObjects > 0) ?
616	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
617
618	int polysSize = 0;
619
620	for (int i = 0; i < limit; ++ i)
621	{
622	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
623	{
624	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
625	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
626	}
627	}
628
629	return polysSize;
630	}
631
632
633	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
634	PolygonContainer &polys,
635	int maxObjects,
636	bool addToBbox)
637	{
638	int limit = (maxObjects > 0) ?
639	Min((int)objects.size(), maxObjects) : (int)objects.size();
640
641	for (int i = 0; i < limit; ++i)
642	{
643	Intersectable object = objects[i];//it;
644	Mesh *mesh = NULL;
645
646	switch (object->Type()) // extract the meshes
647	{
648	case Intersectable::MESH_INSTANCE:
649	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
650	break;
651	case Intersectable::VIEW_CELL:
652	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
653	break;
654	// TODO: handle transformed mesh instances
655	default:
656	Debug << "intersectable type not supported" << endl;
657	break;
658	}
659
660	if (mesh) // copy the mesh data to polygons
661	{
662	if (addToBbox)
663	{
664	mBox.Include(object->GetBox()); // add to BSP tree aabb
665	}
666
667	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
668	}
669	}
670
671	return (int)polys.size();
672	}
673
674
675	void BspTree::Construct(const ViewCellContainer &viewCells)
676	{
677	mStat.nodes = 1;
678	mBox.Initialize(); // initialise bsp tree bounding box
679
680	// copy view cell meshes into one big polygon soup
681	PolygonContainer *polys = new PolygonContainer();
682	mStat.polys = AddToPolygonSoup(viewCells, *polys);
683
684	// view cells are given
685	mGenerateViewCells = false;
686	// construct tree from the view cell polygons
687	Construct(polys, new BoundedRayContainer());
688	}
689
690
691	void BspTree::Construct(const ObjectContainer &objects)
692	{
693	mStat.nodes = 1;
694	mBox.Initialize(); // initialise bsp tree bounding box
695
696	PolygonContainer *polys = new PolygonContainer();
697
698	mGenerateViewCells = true;
699	// copy mesh instance polygons into one big polygon soup
700	mStat.polys = AddToPolygonSoup(objects, *polys);
701
702	// construct tree from polygon soup
703	Construct(polys, new BoundedRayContainer());
704	}
705
706
707	void BspTree::PreprocessPolygons(PolygonContainer &polys)
708	{
709	// preprocess: throw out polygons coincident to the view space box (not needed)
710	PolygonContainer boxPolys;
711	mBox.ExtractPolys(boxPolys);
712	vector<Plane3> boxPlanes;
713
714	PolygonContainer::iterator pit, pit_end = boxPolys.end();
715
716	// extract planes of box
717	// TODO: can be done more elegantly than first extracting polygons
718	// and take their planes
719	for (pit = boxPolys.begin(); pit != pit_end; ++ pit)
720	{
721	boxPlanes.push_back((*pit)->GetSupportingPlane());
722	}
723
724	pit_end = polys.end();
725
726	for (pit = polys.begin(); pit != pit_end; ++ pit)
727	{
728	vector<Plane3>::const_iterator bit, bit_end = boxPlanes.end();
729
730	for (bit = boxPlanes.begin(); (bit != bit_end) && (*pit); ++ bit)
731	{
732	const int cf = (pit)->ClassifyPlane(bit, mEpsilon);
733
734	if (cf == Polygon3::COINCIDENT)
735	{
736	DEL_PTR(*pit);
737	//Debug << "coincident!!" << endl;
738	}
739	}
740	}
741
742	// remove deleted entries
743	for (int i = 0; i < (int)polys.size(); ++ i)
744	{
745	while (!polys[i] && (i < (int)polys.size()))
746	{
747	swap(polys[i], polys.back());
748	polys.pop_back();
749	}
750	}
751	}
752
753
754
755	void BspTree::Construct(const RayContainer &sampleRays,
756	AxisAlignedBox3 *forcedBoundingBox)
757	{
758	mStat.nodes = 1;
759	mBox.Initialize(); // initialise BSP tree bounding box
760
761	if (forcedBoundingBox)
762	mBox = *forcedBoundingBox;
763
764	PolygonContainer *polys = new PolygonContainer();
765	BoundedRayContainer *rays = new BoundedRayContainer();
766
767	RayContainer::const_iterator rit, rit_end = sampleRays.end();
768
769	// generate view cells
770	mGenerateViewCells = true;
771
772	long startTime = GetTime();
773
774	Debug << "** Extracting polygons from rays **\n";
775
776	std::map<Face , Polygon3 > facePolyMap;
777
778	//-- extract polygons intersected by the rays
779	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
780	{
781	Ray ray = rit;
782
783	// get ray-face intersection. Store polygon representing the rays together
784	// with rays intersecting the face.
785	if (!ray->intersections.empty())
786	{
787	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
788	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
789
790	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
791
792	if (it != facePolyMap.end())
793	{
794	//store rays if needed for heuristics
795	if (mSplitPlaneStrategy & BLOCKED_RAYS)
796	(*it).second->mPiercingRays.push_back(ray);
797	}
798	else
799	{ //store rays if needed for heuristics
800	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
801	poly->mParent = obj;
802	polys->push_back(poly);
803
804	if (mSplitPlaneStrategy & BLOCKED_RAYS)
805	poly->mPiercingRays.push_back(ray);
806
807	facePolyMap[face] = poly;
808	}
809	}
810	}
811
812	facePolyMap.clear();
813
814	// compute bounding box
815	if (!forcedBoundingBox)
816	Polygon3::IncludeInBox(*polys, mBox);
817
818	//-- store rays
819	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
820	{
821	Ray ray = rit;
822	ray->SetId(-1); // reset id
823
824	float minT, maxT;
825	if (mBox.GetRaySegment(*ray, minT, maxT))
826	rays->push_back(new BoundedRay(ray, minT, maxT));
827	}
828
829	// throw out bad polygons
830	PreprocessPolygons(*polys);
831
832	mStat.polys = (int)polys->size();
833
834	Debug << "** Finished polygon extraction **" << endl;
835	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
836	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
837
838	Construct(polys, rays);
839	}
840
841
842	void BspTree::Construct(const ObjectContainer &objects,
843	const RayContainer &sampleRays,
844	AxisAlignedBox3 *forcedBoundingBox)
845	{
846	mStat.nodes = 1;
847	mBox.Initialize(); // initialise BSP tree bounding box
848
849	if (forcedBoundingBox)
850	mBox = *forcedBoundingBox;
851
852	BoundedRayContainer *rays = new BoundedRayContainer();
853	PolygonContainer *polys = new PolygonContainer();
854
855	mGenerateViewCells = true;
856
857	// copy mesh instance polygons into one big polygon soup
858	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
859
860
861	RayContainer::const_iterator rit, rit_end = sampleRays.end();
862
863	//-- store rays
864	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
865	{
866	Ray ray = rit;
867	ray->SetId(-1); // reset id
868
869	float minT, maxT;
870	if (mBox.GetRaySegment(*ray, minT, maxT))
871	rays->push_back(new BoundedRay(ray, minT, maxT));
872	}
873
874	PreprocessPolygons(*polys);
875	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
876	Construct(polys, rays);
877	}
878
879
880	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
881	{
882	BspTraversalStack tStack;
883
884	mRoot = new BspLeaf();
885
886	// constrruct root node geometry
887	BspNodeGeometry *geom = new BspNodeGeometry();
888	ConstructGeometry(mRoot, *geom);
889
890	BspTraversalData tData(mRoot,
891	polys,
892	0,
893	GetOrCreateOutOfBoundsCell(),
894	rays,
895	ComputePvsSize(*rays),
896	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
897	geom);
898
899	mTotalCost = tData.mPvs * tData.mProbability / mBox.GetVolume();
900	mTotalPvsSize = tData.mPvs;
901
902	mSubdivisionStats
903	<< "#ViewCells\n1\n" << endl
904	<< "#RenderCostDecrease\n0\n" << endl
905	<< "#TotalRenderCost\n" << mTotalCost << endl
906	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
907
908	tStack.push(tData);
909
910	// used for intermediate time measurements and progress
911	long interTime = GetTime();
912	int nleaves = 500;
913
914	mStat.Start();
915	cout << "Contructing bsp tree ...\n";
916	long startTime = GetTime();
917	while (!tStack.empty())
918	{
919	tData = tStack.top();
920
921	tStack.pop();
922
923	// subdivide leaf node
924	BspNode *r = Subdivide(tStack, tData);
925
926	if (r == mRoot)
927	Debug << "BSP tree construction time spent at root: "
928	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
929
930	if (mStat.Leaves() >= nleaves)
931	{
932	nleaves += 500;
933
934	cout << "leaves=" << mStat.Leaves() << endl;
935	Debug << "needed "
936	<< TimeDiff(interTime, GetTime())*1e-3
937	<< " secs to create 500 leaves" << endl;
938	interTime = GetTime();
939	}
940	}
941
942	cout << "finished\n";
943
944	mStat.Stop();
945	}
946
947
948	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
949	{
950	return
951	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
952	((int)data.mRays->size() <= mTermMinRays) \|\|
953	(data.mPvs <= mTermMinPvs) \|\|
954	(data.mProbability <= mTermMinProbability) \|\|
955	(data.mDepth >= mTermMaxDepth) \|\|
956	(mStat.Leaves() >= mMaxViewCells) \|\|
957	(data.GetAvgRayContribution() > mTermMaxRayContribution));
958	}
959
960
961	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
962	{
963	//-- terminate traversal
964	if (TerminationCriteriaMet(tData))
965	{
966	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
967
968	BspViewCell *viewCell;
969
970	// generate new view cell for each leaf
971	if (mGenerateViewCells)
972	viewCell = new BspViewCell();
973	else
974	// add view cell to leaf
975	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
976
977	leaf->SetViewCell(viewCell);
978	viewCell->mLeaf = leaf;
979
980	if (mUseAreaForPvs)
981	viewCell->SetArea(tData.mProbability);
982	else
983	viewCell->SetVolume(tData.mProbability);
984
985	//-- add pvs
986	if (viewCell != mOutOfBoundsCell)
987	{
988	int conSamp = 0, sampCon = 0;
989	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
990
991	mStat.contributingSamples += conSamp;
992	mStat.sampleContributions += sampCon;
993	}
994
995	EvaluateLeafStats(tData);
996
997	//-- clean up
998
999	// discard polygons
1000	CLEAR_CONTAINER(*tData.mPolygons);
1001	// discard rays
1002	CLEAR_CONTAINER(*tData.mRays);
1003
1004	DEL_PTR(tData.mPolygons);
1005	DEL_PTR(tData.mRays);
1006	DEL_PTR(tData.mGeometry);
1007
1008	return leaf;
1009	}
1010
1011	//-- continue subdivision
1012	PolygonContainer coincident;
1013
1014	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1015	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1016	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1017	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1018
1019
1020	// create new interior node and two leaf nodes
1021	BspInterior *interior =
1022	SubdivideNode(tData, tFrontData, tBackData, coincident);
1023
1024
1025	if (1)
1026	{
1027	int pvsData = tData.mPvs;
1028
1029	float cData = (float)pvsData * tData.mProbability;
1030	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1031	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1032
1033	float costDecr = (cFront + cBack - cData) / mBox.GetVolume();
1034
1035	mTotalCost += costDecr;
1036	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1037
1038	mSubdivisionStats
1039	<< "#ViewCells\n" << mStat.Leaves() << endl
1040	<< "#RenderCostDecrease\n" << -costDecr << endl
1041	<< "#TotalRenderCost\n" << mTotalCost << endl
1042	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1043	}
1044
1045	// extract view cells from coincident polygons according to plane normal
1046	// only if front or back polygons are empty
1047	if (!mGenerateViewCells)
1048	{
1049	ExtractViewCells(tFrontData,
1050	tBackData,
1051	coincident,
1052	interior->mPlane);
1053	}
1054
1055	// don't need coincident polygons anymory
1056	CLEAR_CONTAINER(coincident);
1057
1058	// push the children on the stack
1059	tStack.push(tFrontData);
1060	tStack.push(tBackData);
1061
1062	// cleanup
1063	DEL_PTR(tData.mNode);
1064
1065	DEL_PTR(tData.mPolygons);
1066	DEL_PTR(tData.mRays);
1067	DEL_PTR(tData.mGeometry);
1068
1069	return interior;
1070	}
1071
1072
1073	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1074	BspTraversalData &backData,
1075	const PolygonContainer &coincident,
1076	const Plane3 &splitPlane) const
1077	{
1078	// if not empty, tree is further subdivided => don't have to find view cell
1079	bool foundFront = !frontData.mPolygons->empty();
1080	bool foundBack = !frontData.mPolygons->empty();
1081
1082	PolygonContainer::const_iterator it =
1083	coincident.begin(), it_end = coincident.end();
1084
1085	//-- find first view cells in front and back leafs
1086	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1087	{
1088	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1089	{
1090	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1091	foundBack = true;
1092	}
1093	else
1094	{
1095	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1096	foundFront = true;
1097	}
1098	}
1099	}
1100
1101
1102	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1103	BspTraversalData &frontData,
1104	BspTraversalData &backData,
1105	PolygonContainer &coincident)
1106	{
1107	mStat.nodes += 2;
1108
1109	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1110
1111
1112
1113	// select subdivision plane
1114	BspInterior *interior =
1115	new BspInterior(SelectPlane(leaf, tData));
1116
1117
1118	#ifdef _DEBUG
1119	Debug << interior << endl;
1120	#endif
1121
1122
1123	// subdivide rays into front and back rays
1124	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1125
1126
1127
1128	// subdivide polygons with plane
1129	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1130	*tData.mPolygons,
1131	*frontData.mPolygons,
1132	*backData.mPolygons,
1133	coincident);
1134
1135
1136
1137	// compute pvs
1138	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1139	backData.mPvs = ComputePvsSize(*backData.mRays);
1140
1141	// split geometry and compute area
1142	if (1)
1143	{
1144	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1145	*backData.mGeometry,
1146	interior->mPlane,
1147	mBox,
1148	//0.000000000001);
1149	mEpsilon);
1150
1151
1152	if (mUseAreaForPvs)
1153	{
1154	frontData.mProbability = frontData.mGeometry->GetArea();
1155	backData.mProbability = backData.mGeometry->GetArea();
1156	}
1157	else
1158	{
1159	frontData.mProbability = frontData.mGeometry->GetVolume();
1160	backData.mProbability = tData.mProbability - frontData.mProbability;
1161	}
1162	}
1163
1164	//-- create front and back leaf
1165
1166	BspInterior *parent = leaf->GetParent();
1167
1168	// replace a link from node's parent
1169	if (!leaf->IsRoot())
1170	{
1171	parent->ReplaceChildLink(leaf, interior);
1172	interior->SetParent(parent);
1173	}
1174	else // new root
1175	{
1176	mRoot = interior;
1177	}
1178
1179	// and setup child links
1180	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1181
1182	frontData.mNode = interior->GetFront();
1183	backData.mNode = interior->GetBack();
1184
1185	interior->mTimeStamp = mTimeStamp ++;
1186
1187	//DEL_PTR(leaf);
1188	return interior;
1189	}
1190
1191
1192	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1193	const int axis,
1194	vector<SortableEntry> &splitCandidates) const
1195	{
1196	splitCandidates.clear();
1197
1198	int requestedSize = 2 * (int)polys.size();
1199	// creates a sorted split candidates array
1200	splitCandidates.reserve(requestedSize);
1201
1202	PolygonContainer::const_iterator it, it_end = polys.end();
1203
1204	AxisAlignedBox3 box;
1205
1206	// insert all queries
1207	for(it = polys.begin(); it != it_end; ++ it)
1208	{
1209	box.Initialize();
1210	box.Include((it));
1211
1212	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1213	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1214	}
1215
1216	stable_sort(splitCandidates.begin(), splitCandidates.end());
1217	}
1218
1219
1220	float BspTree::BestCostRatio(const PolygonContainer &polys,
1221	const AxisAlignedBox3 &box,
1222	const int axis,
1223	float &position,
1224	int &objectsBack,
1225	int &objectsFront) const
1226	{
1227	vector<SortableEntry> splitCandidates;
1228
1229	SortSplitCandidates(polys, axis, splitCandidates);
1230
1231	// go through the lists, count the number of objects left and right
1232	// and evaluate the following cost funcion:
1233	// C = ct_div_ci + (ol + or)/queries
1234
1235	int objectsLeft = 0, objectsRight = (int)polys.size();
1236
1237	float minBox = box.Min(axis);
1238	float maxBox = box.Max(axis);
1239	float boxArea = box.SurfaceArea();
1240
1241	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1242	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1243
1244	float minSum = 1e20f;
1245	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1246
1247	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1248	{
1249	switch ((*ci).type)
1250	{
1251	case SortableEntry::POLY_MIN:
1252	++ objectsLeft;
1253	break;
1254	case SortableEntry::POLY_MAX:
1255	-- objectsRight;
1256	break;
1257	default:
1258	break;
1259	}
1260
1261	if ((ci).value > minBand && (ci).value < maxBand)
1262	{
1263	AxisAlignedBox3 lbox = box;
1264	AxisAlignedBox3 rbox = box;
1265	lbox.SetMax(axis, (*ci).value);
1266	rbox.SetMin(axis, (*ci).value);
1267
1268	const float sum = objectsLeft * lbox.SurfaceArea() +
1269	objectsRight * rbox.SurfaceArea();
1270
1271	if (sum < minSum)
1272	{
1273	minSum = sum;
1274	position = (*ci).value;
1275
1276	objectsBack = objectsLeft;
1277	objectsFront = objectsRight;
1278	}
1279	}
1280	}
1281
1282	const float oldCost = (float)polys.size();
1283	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1284	const float ratio = newCost / oldCost;
1285
1286
1287	#if 0
1288	Debug << "====================" << endl;
1289	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1290	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1291	#endif
1292	return ratio;
1293	}
1294
1295	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1296	const PolygonContainer &polys) const
1297	{
1298	AxisAlignedBox3 box;
1299	box.Initialize();
1300
1301	// create bounding box of region
1302	Polygon3::IncludeInBox(polys, box);
1303
1304	int objectsBack = 0, objectsFront = 0;
1305	int axis = 0;
1306	float costRatio = MAX_FLOAT;
1307	Vector3 position;
1308
1309	//-- area subdivision
1310	for (int i = 0; i < 3; ++ i)
1311	{
1312	float p = 0;
1313	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1314
1315	if (r < costRatio)
1316	{
1317	costRatio = r;
1318	axis = i;
1319	position = p;
1320	}
1321	}
1322
1323	if (costRatio >= mMaxCostRatio)
1324	return false;
1325
1326	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1327	plane = Plane3(norm, position);
1328
1329	return true;
1330	}
1331
1332
1333	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1334	{
1335	if ((!mMaxPolyCandidates \|\| data.mPolygons->empty()) &&
1336	(!mMaxRayCandidates \|\| data.mRays->empty()))
1337	{
1338	Debug << "Warning: No autopartition polygon candidate available\n";
1339
1340	// return axis aligned split
1341	AxisAlignedBox3 box;
1342	box.Initialize();
1343
1344	// create bounding box of region
1345	Polygon3::IncludeInBox(*data.mPolygons, box);
1346
1347	const int axis = box.Size().DrivingAxis();
1348	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1349
1350	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1351	return Plane3(norm, position);
1352	}
1353
1354	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1355	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1356	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1357	((mTermMinObjectsForAxisAligned < 0) \|\|
1358	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1359	{
1360	Plane3 plane;
1361	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1362	return plane;
1363	}
1364
1365	// simplest strategy: just take next polygon
1366	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1367	{
1368	if (!data.mPolygons->empty())
1369	{
1370	Polygon3 *nextPoly =
1371	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1372	return nextPoly->GetSupportingPlane();
1373	}
1374	else
1375	{
1376	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1377	BoundedRay bRay = (data.mRays)[candidateIdx];
1378
1379	Ray *ray = bRay->mRay;
1380
1381	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1382	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1383
1384	const Vector3 pt = (maxPt + minPt) * 0.5;
1385
1386	const Vector3 normal = ray->GetDir();
1387
1388	return Plane3(normal, pt);
1389	}
1390
1391	return Plane3();
1392	}
1393
1394	// use heuristics to find appropriate plane
1395	return SelectPlaneHeuristics(leaf, data);
1396	}
1397
1398
1399	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1400	{
1401	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1402	BoundedRay *bRay = rays[candidateIdx];
1403	Ray *ray = bRay->mRay;
1404
1405	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1406	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1407
1408	const Vector3 pt = (maxPt + minPt) * 0.5;
1409
1410	const Vector3 normal = ray->GetDir();
1411
1412	return Plane3(normal, pt);
1413	}
1414
1415	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1416	{
1417	Vector3 pt[3];
1418	int idx[3];
1419	int cmaxT = 0;
1420	int cminT = 0;
1421	bool chooseMin = false;
1422
1423	for (int j = 0; j < 3; j ++)
1424	{
1425	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1426
1427	if (idx[j] >= (int)rays.size())
1428	{
1429	idx[j] -= (int)rays.size();
1430	chooseMin = (cminT < 2);
1431	}
1432	else
1433	chooseMin = (cmaxT < 2);
1434
1435	BoundedRay *bRay = rays[idx[j]];
1436	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1437	bRay->mRay->Extrap(bRay->mMaxT);
1438	}
1439
1440	return Plane3(pt[0], pt[1], pt[2]);
1441	}
1442
1443	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1444	{
1445	Vector3 pt[3];
1446
1447	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1448	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1449
1450	// check if rays different
1451	if (idx1 == idx2)
1452	idx2 = (idx2 + 1) % (int)rays.size();
1453
1454	const BoundedRay *ray1 = rays[idx1];
1455	const BoundedRay *ray2 = rays[idx2];
1456
1457	// normal vector of the plane parallel to both lines
1458	const Vector3 norm =
1459	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1460
1461	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1462	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1463
1464	// vector from line 1 to line 2
1465	const Vector3 vd = orig1 - orig2;
1466
1467	// project vector on normal to get distance
1468	const float dist = DotProd(vd, norm);
1469
1470	// point on plane lies halfway between the two planes
1471	const Vector3 planePt = orig1 + norm * dist * 0.5;
1472
1473	return Plane3(norm, planePt);
1474	}
1475
1476
1477	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1478	{
1479	float lowestCost = MAX_FLOAT;
1480	Plane3 bestPlane;
1481	// intermediate plane
1482	Plane3 plane;
1483
1484	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1485	int maxIdx = (int)data.mPolygons->size();
1486
1487	for (int i = 0; i < limit; ++ i)
1488	{
1489	// assure that no index is taken twice
1490	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1491
1492	Polygon3 poly = (data.mPolygons)[candidateIdx];
1493
1494	// swap candidate to the end to avoid testing same plane
1495	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1496	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1497
1498	// evaluate current candidate
1499	const float candidateCost =
1500	SplitPlaneCost(poly->GetSupportingPlane(), data);
1501
1502	if (candidateCost < lowestCost)
1503	{
1504	bestPlane = poly->GetSupportingPlane();
1505	lowestCost = candidateCost;
1506	}
1507	}
1508
1509	//-- choose candidate planes extracted from rays
1510	for (int i = 0; i < mMaxRayCandidates; ++ i)
1511	{
1512	plane = ChooseCandidatePlane3(*data.mRays);
1513	const float candidateCost = SplitPlaneCost(plane, data);
1514
1515	if (candidateCost < lowestCost)
1516	{
1517	bestPlane = plane;
1518	lowestCost = candidateCost;
1519	}
1520	}
1521
1522	#ifdef _DEBUG
1523	Debug << "plane lowest cost: " << lowestCost << endl;
1524	#endif
1525
1526	return bestPlane;
1527	}
1528
1529
1530	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1531	const PolygonContainer &polys) const
1532	{
1533	float val = 0;
1534
1535	float sumBalancedPolys = 0;
1536	float sumSplits = 0;
1537	float sumPolyArea = 0;
1538	float sumBalancedViewCells = 0;
1539	float sumBlockedRays = 0;
1540	float totalBlockedRays = 0;
1541	//float totalArea = 0;
1542	int totalViewCells = 0;
1543
1544	// need three unique ids for each type of view cell
1545	// for balanced view cells criterium
1546	ViewCell::NewMail();
1547	const int backId = ViewCell::sMailId;
1548	ViewCell::NewMail();
1549	const int frontId = ViewCell::sMailId;
1550	ViewCell::NewMail();
1551	const int frontAndBackId = ViewCell::sMailId;
1552
1553	bool useRand;
1554	int limit;
1555
1556	// choose test polyongs randomly if over threshold
1557	if ((int)polys.size() > mMaxTests)
1558	{
1559	useRand = true;
1560	limit = mMaxTests;
1561	}
1562	else
1563	{
1564	useRand = false;
1565	limit = (int)polys.size();
1566	}
1567
1568	for (int i = 0; i < limit; ++ i)
1569	{
1570	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1571
1572	Polygon3 *poly = polys[testIdx];
1573
1574	const int classification =
1575	poly->ClassifyPlane(candidatePlane, mEpsilon);
1576
1577	if (mSplitPlaneStrategy & BALANCED_POLYS)
1578	sumBalancedPolys += sBalancedPolysTable[classification];
1579
1580	if (mSplitPlaneStrategy & LEAST_SPLITS)
1581	sumSplits += sLeastPolySplitsTable[classification];
1582
1583	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1584	{
1585	if (classification == Polygon3::COINCIDENT)
1586	sumPolyArea += poly->GetArea();
1587	//totalArea += area;
1588	}
1589
1590	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1591	{
1592	const float blockedRays = (float)poly->mPiercingRays.size();
1593
1594	if (classification == Polygon3::COINCIDENT)
1595	sumBlockedRays += blockedRays;
1596
1597	totalBlockedRays += blockedRays;
1598	}
1599
1600	// assign view cells to back or front according to classificaion
1601	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1602	{
1603	MeshInstance *viewCell = poly->mParent;
1604
1605	// assure that we only count a view cell
1606	// once for the front and once for the back side of the plane
1607	if (classification == Polygon3::FRONT_SIDE)
1608	{
1609	if ((viewCell->mMailbox != frontId) &&
1610	(viewCell->mMailbox != frontAndBackId))
1611	{
1612	sumBalancedViewCells += 1.0;
1613
1614	if (viewCell->mMailbox != backId)
1615	viewCell->mMailbox = frontId;
1616	else
1617	viewCell->mMailbox = frontAndBackId;
1618
1619	++ totalViewCells;
1620	}
1621	}
1622	else if (classification == Polygon3::BACK_SIDE)
1623	{
1624	if ((viewCell->mMailbox != backId) &&
1625	(viewCell->mMailbox != frontAndBackId))
1626	{
1627	sumBalancedViewCells -= 1.0;
1628
1629	if (viewCell->mMailbox != frontId)
1630	viewCell->mMailbox = backId;
1631	else
1632	viewCell->mMailbox = frontAndBackId;
1633
1634	++ totalViewCells;
1635	}
1636	}
1637	}
1638	}
1639
1640	const float polysSize = (float)polys.size() + Limits::Small;
1641
1642	// all values should be approx. between 0 and 1 so they can be combined
1643	// and scaled with the factors according to their importance
1644	if (mSplitPlaneStrategy & BALANCED_POLYS)
1645	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1646
1647	if (mSplitPlaneStrategy & LEAST_SPLITS)
1648	val += mLeastSplitsFactor * sumSplits / polysSize;
1649
1650	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1651	// HACK: polys.size should be total area so scaling is between 0 and 1
1652	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1653
1654	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1655	if (totalBlockedRays != 0)
1656	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1657
1658	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1659	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1660	((float)totalViewCells + Limits::Small);
1661
1662	return val;
1663	}
1664
1665
1666	inline void BspTree::GenerateUniqueIdsForPvs()
1667	{
1668	ViewCell::NewMail(); sBackId = ViewCell::sMailId;
1669	ViewCell::NewMail(); sFrontId = ViewCell::sMailId;
1670	ViewCell::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1671	}
1672
1673
1674	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1675	const BoundedRayContainer &rays,
1676	const int pvs,
1677	const float probability,
1678	const BspNodeGeometry &cell) const
1679	{
1680	float val = 0;
1681
1682	float sumBalancedRays = 0;
1683	float sumRaySplits = 0;
1684
1685	int frontPvs = 0;
1686	int backPvs = 0;
1687
1688	// probability that view point lies in child
1689	float pOverall = 0;
1690	float pFront = 0;
1691	float pBack = 0;
1692
1693	const bool pvsUseLen = false;
1694
1695	if (mSplitPlaneStrategy & PVS)
1696	{
1697	// create unique ids for pvs heuristics
1698	GenerateUniqueIdsForPvs();
1699
1700	// construct child geometry with regard to the candidate split plane
1701	BspNodeGeometry frontCell;
1702	BspNodeGeometry backCell;
1703
1704	cell.SplitGeometry(frontCell,
1705	backCell,
1706	candidatePlane,
1707	mBox,
1708	mEpsilon);
1709
1710	if (mUseAreaForPvs)
1711	{
1712	pFront = frontCell.GetArea();
1713	pBack = backCell.GetArea();
1714	}
1715	else
1716	{
1717	pFront = frontCell.GetVolume();
1718	pBack = pOverall - pFront;
1719	}
1720
1721
1722	pOverall = probability;
1723	}
1724
1725	bool useRand;
1726	int limit;
1727
1728	// choose test polyongs randomly if over threshold
1729	if ((int)rays.size() > mMaxTests)
1730	{
1731	useRand = true;
1732	limit = mMaxTests;
1733	}
1734	else
1735	{
1736	useRand = false;
1737	limit = (int)rays.size();
1738	}
1739
1740	for (int i = 0; i < limit; ++ i)
1741	{
1742	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1743
1744	BoundedRay *bRay = rays[testIdx];
1745
1746	Ray *ray = bRay->mRay;
1747	const float minT = bRay->mMinT;
1748	const float maxT = bRay->mMaxT;
1749
1750	Vector3 entP, extP;
1751
1752	const int cf =
1753	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1754
1755	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1756	{
1757	sumBalancedRays += sBalancedRaysTable[cf];
1758	}
1759
1760	if (mSplitPlaneStrategy & BALANCED_RAYS)
1761	{
1762	sumRaySplits += sLeastRaySplitsTable[cf];
1763	}
1764
1765	if (mSplitPlaneStrategy & PVS)
1766	{
1767	// in case the ray intersects an object
1768	// assure that we only count the object
1769	// once for the front and once for the back side of the plane
1770
1771	// add the termination object
1772	if (!ray->intersections.empty())
1773	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1774
1775	// add the source object
1776	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1777	}
1778	}
1779
1780	const float raysSize = (float)rays.size() + Limits::Small;
1781
1782	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1783	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1784
1785	if (mSplitPlaneStrategy & BALANCED_RAYS)
1786	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1787
1788	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1789
1790	if (mSplitPlaneStrategy & PVS)
1791	{
1792	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1793
1794	// give penalty to unbalanced split
1795	if (0)
1796	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1797	(pFront < (pBack * 0.2 + Limits::Small)))
1798	val += 0.5;
1799	}
1800
1801
1802	#ifdef _DEBUG
1803	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1804	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1805	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1806	#endif
1807
1808	return val;
1809	}
1810
1811	void BspTree::AddObjToPvs(Intersectable *obj,
1812	const int cf,
1813	int &frontPvs,
1814	int &backPvs) const
1815	{
1816	if (!obj)
1817	return;
1818	// TODO: does this really belong to no pvs?
1819	//if (cf == Ray::COINCIDENT) return;
1820
1821	// object belongs to both PVS
1822	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1823	(cf == Ray::BACK_FRONT) \|\|
1824	(cf == Ray::COINCIDENT);
1825
1826	if ((cf == Ray::FRONT) \|\| bothSides)
1827	{
1828	if ((obj->mMailbox != sFrontId) &&
1829	(obj->mMailbox != sFrontAndBackId))
1830	{
1831	++ frontPvs;
1832
1833	if (obj->mMailbox == sBackId)
1834	obj->mMailbox = sFrontAndBackId;
1835	else
1836	obj->mMailbox = sFrontId;
1837	}
1838	}
1839
1840	if ((cf == Ray::BACK) \|\| bothSides)
1841	{
1842	if ((obj->mMailbox != sBackId) &&
1843	(obj->mMailbox != sFrontAndBackId))
1844	{
1845	++ backPvs;
1846
1847	if (obj->mMailbox == sFrontId)
1848	obj->mMailbox = sFrontAndBackId;
1849	else
1850	obj->mMailbox = sBackId;
1851	}
1852	}
1853	}
1854
1855
1856	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1857	BspTraversalData &data) const
1858	{
1859	float val = 0;
1860
1861	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1862	{
1863	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1864	// we put a penalty on the dot product between the "tiny" vertical axis
1865	// and the split plane axis
1866	val += mVerticalSplitsFactor *
1867	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1868	}
1869
1870	// the following criteria loop over all polygons to find the cost value
1871	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1872	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1873	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1874	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1875	(mSplitPlaneStrategy & BLOCKED_RAYS))
1876	{
1877	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1878	}
1879
1880	// the following criteria loop over all rays to find the cost value
1881	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1882	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1883	(mSplitPlaneStrategy & PVS))
1884	{
1885	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1886	data.mProbability, *data.mGeometry);
1887	}
1888
1889	// return linear combination of the sums
1890	return val;
1891	}
1892
1893	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1894	{
1895	stack<BspNode *> nodeStack;
1896	nodeStack.push(mRoot);
1897
1898	while (!nodeStack.empty())
1899	{
1900	BspNode *node = nodeStack.top();
1901
1902	nodeStack.pop();
1903
1904	if (node->IsLeaf())
1905	{
1906	BspLeaf leaf = (BspLeaf )node;
1907	leaves.push_back(leaf);
1908	}
1909	else
1910	{
1911	BspInterior interior = dynamic_cast<BspInterior >(node);
1912
1913	nodeStack.push(interior->GetBack());
1914	nodeStack.push(interior->GetFront());
1915	}
1916	}
1917	}
1918
1919
1920	AxisAlignedBox3 BspTree::GetBoundingBox() const
1921	{
1922	return mBox;
1923	}
1924
1925
1926	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1927	{
1928	// the node became a leaf -> evaluate stats for leafs
1929	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1930
1931	// store maximal and minimal depth
1932	if (data.mDepth > mStat.maxDepth)
1933	mStat.maxDepth = data.mDepth;
1934
1935	if (data.mDepth < mStat.minDepth)
1936	mStat.minDepth = data.mDepth;
1937
1938	// accumulate depth to compute average depth
1939	mStat.accumDepth += data.mDepth;
1940	// accumulate rays to compute rays / leaf
1941	mStat.accumRays += (int)data.mRays->size();
1942
1943	if (data.mDepth >= mTermMaxDepth)
1944	++ mStat.maxDepthNodes;
1945
1946	if (data.mPvs < mTermMinPvs)
1947	++ mStat.minPvsNodes;
1948
1949	if ((int)data.mRays->size() < mTermMinRays)
1950	++ mStat.minRaysNodes;
1951
1952	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1953	++ mStat.maxRayContribNodes;
1954
1955	if (data.mProbability <= mTermMinProbability)
1956	++ mStat.minProbabilityNodes;
1957
1958	#ifdef _DEBUG
1959	Debug << "BSP stats: "
1960	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1961	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1962	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
1963	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1964	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1965	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1966	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1967	#endif
1968	}
1969
1970	int
1971	BspTree::_CastRay(Ray &ray)
1972	{
1973	int hits = 0;
1974
1975	stack<BspRayTraversalData> tStack;
1976
1977	float maxt, mint;
1978
1979	if (!mBox.GetRaySegment(ray, mint, maxt))
1980	return 0;
1981
1982	ViewCell::NewMail();
1983
1984	Vector3 entp = ray.Extrap(mint);
1985	Vector3 extp = ray.Extrap(maxt);
1986
1987	BspNode *node = mRoot;
1988	BspNode *farChild = NULL;
1989
1990	while (1)
1991	{
1992	if (!node->IsLeaf())
1993	{
1994	BspInterior in = dynamic_cast<BspInterior >(node);
1995
1996	Plane3 splitPlane = in->GetPlane();
1997	const int entSide = splitPlane.Side(entp);
1998	const int extSide = splitPlane.Side(extp);
1999
2000	if (entSide < 0)
2001	{
2002	node = in->GetBack();
2003
2004	if(extSide <= 0) // plane does not split ray => no far child
2005	continue;
2006
2007	farChild = in->GetFront(); // plane splits ray
2008
2009	} else if (entSide > 0)
2010	{
2011	node = in->GetFront();
2012
2013	if (extSide >= 0) // plane does not split ray => no far child
2014	continue;
2015
2016	farChild = in->GetBack(); // plane splits ray
2017	}
2018	else // ray and plane are coincident
2019	{
2020	// WHAT TO DO IN THIS CASE ?
2021	//break;
2022	node = in->GetFront();
2023	continue;
2024	}
2025
2026	// push data for far child
2027	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2028
2029	// find intersection of ray segment with plane
2030	float t;
2031	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
2032	maxt *= t;
2033
2034	} else // reached leaf => intersection with view cell
2035	{
2036	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2037
2038	if (!leaf->mViewCell->Mailed())
2039	{
2040	//ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
2041	leaf->mViewCell->Mail();
2042	++ hits;
2043	}
2044
2045	//-- fetch the next far child from the stack
2046	if (tStack.empty())
2047	break;
2048
2049	entp = extp;
2050	mint = maxt; // NOTE: need this?
2051
2052	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
2053	break;
2054
2055	BspRayTraversalData &s = tStack.top();
2056
2057	node = s.mNode;
2058	extp = s.mExitPoint;
2059	maxt = s.mMaxT;
2060
2061	tStack.pop();
2062	}
2063	}
2064
2065	return hits;
2066	}
2067
2068
2069	int BspTree::CastLineSegment(const Vector3 &origin,
2070	const Vector3 &termination,
2071	vector<ViewCell *> &viewcells)
2072	{
2073	int hits = 0;
2074	stack<BspRayTraversalData> tStack;
2075
2076	float mint = 0.0f, maxt = 1.0f;
2077
2078	Intersectable::NewMail();
2079	ViewCell::NewMail();
2080
2081	Vector3 entp = origin;
2082	Vector3 extp = termination;
2083
2084	BspNode *node = mRoot;
2085	BspNode *farChild = NULL;
2086
2087	while (1)
2088	{
2089	if (!node->IsLeaf())
2090	{
2091	BspInterior in = dynamic_cast<BspInterior >(node);
2092
2093	Plane3 splitPlane = in->GetPlane();
2094
2095	const int entSide = splitPlane.Side(entp);
2096	const int extSide = splitPlane.Side(extp);
2097
2098	if (entSide < 0)
2099	{
2100	node = in->GetBack();
2101
2102	if(extSide <= 0) // plane does not split ray => no far child
2103	continue;
2104
2105	farChild = in->GetFront(); // plane splits ray
2106
2107	}
2108	else if (entSide > 0)
2109	{
2110	node = in->GetFront();
2111
2112	if (extSide >= 0) // plane does not split ray => no far child
2113	continue;
2114
2115	farChild = in->GetBack(); // plane splits ray
2116	}
2117	else // ray and plane are coincident
2118	{
2119	// NOTE: what to do if ray is coincident with plane?
2120	if (extSide < 0)
2121	node = in->GetBack();
2122	else
2123	node = in->GetFront();
2124
2125	continue; // no far child
2126	}
2127
2128	// push data for far child
2129	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2130
2131	// find intersection of ray segment with plane
2132	float t;
2133	extp = splitPlane.FindIntersection(origin, extp, &t);
2134	maxt *= t;
2135	}
2136	else
2137	{
2138	// reached leaf => intersection with view cell
2139	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2140
2141	if (!leaf->mViewCell->Mailed())
2142	{
2143	viewcells.push_back(leaf->mViewCell);
2144	leaf->mViewCell->Mail();
2145	hits++;
2146	}
2147
2148	//-- fetch the next far child from the stack
2149	if (tStack.empty())
2150	break;
2151
2152	entp = extp;
2153	mint = maxt; // NOTE: need this?
2154
2155	BspRayTraversalData &s = tStack.top();
2156
2157	node = s.mNode;
2158	extp = s.mExitPoint;
2159	maxt = s.mMaxT;
2160
2161	tStack.pop();
2162	}
2163	}
2164	return hits;
2165	}
2166
2167
2168	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2169	{
2170	stack<BspNode *> nodeStack;
2171	nodeStack.push(mRoot);
2172
2173	ViewCell::NewMail();
2174
2175	while (!nodeStack.empty())
2176	{
2177	BspNode *node = nodeStack.top();
2178	nodeStack.pop();
2179
2180	if (node->IsLeaf())
2181	{
2182	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2183
2184	if (!viewCell->Mailed())
2185	{
2186	viewCell->Mail();
2187	viewCells.push_back(viewCell);
2188	}
2189	}
2190	else
2191	{
2192	BspInterior interior = dynamic_cast<BspInterior >(node);
2193
2194	nodeStack.push(interior->GetFront());
2195	nodeStack.push(interior->GetBack());
2196	}
2197	}
2198	}
2199
2200
2201	BspTreeStatistics &BspTree::GetStat()
2202	{
2203	return mStat;
2204	}
2205
2206
2207	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2208	{
2209	float len = 0;
2210
2211	BoundedRayContainer::const_iterator it, it_end = rays.end();
2212
2213	for (it = rays.begin(); it != it_end; ++ it)
2214	{
2215	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2216	(it)->mRay->Extrap((it)->mMaxT));
2217	}
2218
2219	return len;
2220	}
2221
2222
2223	int BspTree::SplitRays(const Plane3 &plane,
2224	BoundedRayContainer &rays,
2225	BoundedRayContainer &frontRays,
2226	BoundedRayContainer &backRays)
2227	{
2228	int splits = 0;
2229
2230	while (!rays.empty())
2231	{
2232	BoundedRay *bRay = rays.back();
2233	Ray *ray = bRay->mRay;
2234	float minT = bRay->mMinT;
2235	float maxT = bRay->mMaxT;
2236
2237	rays.pop_back();
2238
2239	Vector3 entP, extP;
2240
2241	const int cf =
2242	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2243
2244	// set id to ray classification
2245	ray->SetId(cf);
2246
2247	switch (cf)
2248	{
2249	case Ray::COINCIDENT: // TODO: should really discard ray?
2250	frontRays.push_back(bRay);
2251	//DEL_PTR(bRay);
2252	break;
2253	case Ray::BACK:
2254	backRays.push_back(bRay);
2255	break;
2256	case Ray::FRONT:
2257	frontRays.push_back(bRay);
2258	break;
2259	case Ray::FRONT_BACK:
2260	{
2261	// find intersection of ray segment with plane
2262	const float t = plane.FindT(ray->GetLoc(), extP);
2263
2264	const float newT = t * maxT;
2265
2266	frontRays.push_back(new BoundedRay(ray, minT, newT));
2267	backRays.push_back(new BoundedRay(ray, newT, maxT));
2268
2269	DEL_PTR(bRay);
2270	}
2271	break;
2272	case Ray::BACK_FRONT:
2273	{
2274	// find intersection of ray segment with plane
2275	const float t = plane.FindT(ray->GetLoc(), extP);
2276	const float newT = t * bRay->mMaxT;
2277
2278	backRays.push_back(new BoundedRay(ray, minT, newT));
2279	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2280
2281	DEL_PTR(bRay);
2282
2283	++ splits;
2284	}
2285	break;
2286	default:
2287	Debug << "Should not come here 4" << endl;
2288	break;
2289	}
2290	}
2291
2292	return splits;
2293	}
2294
2295	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2296	{
2297	BspNode *lastNode;
2298	do
2299	{
2300	lastNode = n;
2301
2302	// want to get planes defining geometry of this node => don't take
2303	// split plane of node itself
2304	n = n->GetParent();
2305
2306	if (n)
2307	{
2308	BspInterior interior = dynamic_cast<BspInterior >(n);
2309	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2310
2311	if (interior->GetFront() != lastNode)
2312	halfSpace.ReverseOrientation();
2313
2314	halfSpaces.push_back(halfSpace);
2315	}
2316	}
2317	while (n);
2318	}
2319
2320
2321
2322	void BspTree::ConstructGeometry(ViewCell *vc,
2323	BspNodeGeometry &vcGeom) const
2324	{
2325	ViewCellContainer leaves;
2326	mViewCellsTree->CollectLeaves(vc, leaves);
2327
2328	ViewCellContainer::const_iterator it, it_end = leaves.end();
2329
2330	for (it = leaves.begin(); it != it_end; ++ it)
2331	{
2332	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2333	ConstructGeometry(l, vcGeom);
2334	}
2335	}
2336
2337
2338	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2339	{
2340	mViewCellsManager = vcm;
2341	}
2342
2343
2344	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2345	{
2346	vector<Plane3> halfSpaces;
2347	ExtractHalfSpaces(n, halfSpaces);
2348
2349	PolygonContainer candidates;
2350
2351	// bounded planes are added to the polygons (reverse polygons
2352	// as they have to be outfacing
2353	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2354	{
2355	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2356
2357	if (p->Valid(mEpsilon))
2358	{
2359	candidates.push_back(p->CreateReversePolygon());
2360	DEL_PTR(p);
2361	}
2362	}
2363
2364	// add faces of bounding box (also could be faces of the cell)
2365	for (int i = 0; i < 6; ++ i)
2366	{
2367	VertexContainer vertices;
2368
2369	for (int j = 0; j < 4; ++ j)
2370	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2371
2372	candidates.push_back(new Polygon3(vertices));
2373	}
2374
2375	for (int i = 0; i < (int)candidates.size(); ++ i)
2376	{
2377	// polygon is split by all other planes
2378	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2379	{
2380	if (i == j) // polygon and plane are coincident
2381	continue;
2382
2383	VertexContainer splitPts;
2384	Polygon3 frontPoly, backPoly;
2385
2386	const int cf = candidates[i]->
2387	ClassifyPlane(halfSpaces[j], mEpsilon);
2388
2389	switch (cf)
2390	{
2391	case Polygon3::SPLIT:
2392	frontPoly = new Polygon3();
2393	backPoly = new Polygon3();
2394
2395	candidates[i]->Split(halfSpaces[j],
2396	*frontPoly,
2397	*backPoly,
2398	mEpsilon);
2399
2400	DEL_PTR(candidates[i]);
2401
2402	if (frontPoly->Valid(mEpsilon))
2403	candidates[i] = frontPoly;
2404	else
2405	DEL_PTR(frontPoly);
2406
2407	DEL_PTR(backPoly);
2408	break;
2409	case Polygon3::BACK_SIDE:
2410	DEL_PTR(candidates[i]);
2411	break;
2412	// just take polygon as it is
2413	case Polygon3::FRONT_SIDE:
2414	case Polygon3::COINCIDENT:
2415	default:
2416	break;
2417	}
2418	}
2419
2420	if (candidates[i])
2421	geom.mPolys.push_back(candidates[i]);
2422	}
2423	}
2424
2425
2426	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2427
2428
2429	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2430	const bool onlyUnmailed) const
2431	{
2432	stack<bspNodePair> nodeStack;
2433
2434	BspNodeGeometry nodeGeom;
2435	ConstructGeometry(n, nodeGeom);
2436
2437	// split planes from the root to this node
2438	// needed to verify that we found neighbor leaf
2439	// TODO: really needed?
2440	vector<Plane3> halfSpaces;
2441	ExtractHalfSpaces(n, halfSpaces);
2442
2443
2444	BspNodeGeometry *rgeom = new BspNodeGeometry();
2445	ConstructGeometry(mRoot, *rgeom);
2446
2447	nodeStack.push(bspNodePair(mRoot, rgeom));
2448
2449	while (!nodeStack.empty())
2450	{
2451	BspNode *node = nodeStack.top().first;
2452	BspNodeGeometry *geom = nodeStack.top().second;
2453
2454	nodeStack.pop();
2455
2456	if (node->IsLeaf())
2457	{
2458	// test if this leaf is in valid view space
2459	if (node->TreeValid() &&
2460	(node != n) &&
2461	(!onlyUnmailed \|\| !node->Mailed()))
2462	{
2463	bool isAdjacent = true;
2464
2465	if (1)
2466	{
2467	// test all planes of current node if still adjacent
2468	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2469	{
2470	const int cf =
2471	Polygon3::ClassifyPlane(geom->mPolys,
2472	halfSpaces[i],
2473	mEpsilon);
2474
2475	if (cf == Polygon3::BACK_SIDE)
2476	{
2477	isAdjacent = false;
2478	}
2479	}
2480	}
2481	else
2482	{
2483	// TODO: why is this wrong??
2484	// test all planes of current node if still adjacent
2485	for (int i = 0; (i < (int)nodeGeom.mPolys.size()) && isAdjacent; ++ i)
2486	{
2487	Polygon3 *poly = nodeGeom.mPolys[i];
2488
2489	const int cf =
2490	Polygon3::ClassifyPlane(geom->mPolys,
2491	poly->GetSupportingPlane(),
2492	mEpsilon);
2493
2494	if (cf == Polygon3::BACK_SIDE)
2495	{
2496	isAdjacent = false;
2497	}
2498	}
2499	}
2500	// neighbor was found
2501	if (isAdjacent)
2502	{
2503	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2504	}
2505	}
2506	}
2507	else
2508	{
2509	BspInterior interior = dynamic_cast<BspInterior >(node);
2510
2511	const int cf = Polygon3::ClassifyPlane(nodeGeom.mPolys,
2512	interior->GetPlane(),
2513	mEpsilon);
2514
2515	BspNode *front = interior->GetFront();
2516	BspNode *back = interior->GetBack();
2517
2518	BspNodeGeometry *fGeom = new BspNodeGeometry();
2519	BspNodeGeometry *bGeom = new BspNodeGeometry();
2520
2521	geom->SplitGeometry(*fGeom,
2522	*bGeom,
2523	interior->GetPlane(),
2524	mBox,
2525	mEpsilon);
2526
2527	if (cf == Polygon3::FRONT_SIDE)
2528	{
2529	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2530	DEL_PTR(bGeom);
2531	}
2532	else
2533	{
2534	if (cf == Polygon3::BACK_SIDE)
2535	{
2536	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2537	DEL_PTR(fGeom);
2538	}
2539	else
2540	{ // random decision
2541	nodeStack.push(bspNodePair(front, fGeom));
2542	nodeStack.push(bspNodePair(back, bGeom));
2543	}
2544	}
2545	}
2546
2547	DEL_PTR(geom);
2548	}
2549
2550	return (int)neighbors.size();
2551	}
2552
2553
2554	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2555	{
2556	stack<BspNode *> nodeStack;
2557	nodeStack.push(mRoot);
2558
2559	int mask = rand();
2560
2561	while (!nodeStack.empty())
2562	{
2563	BspNode *node = nodeStack.top();
2564	nodeStack.pop();
2565
2566	if (node->IsLeaf())
2567	{
2568	return dynamic_cast<BspLeaf *>(node);
2569	}
2570	else
2571	{
2572	BspInterior interior = dynamic_cast<BspInterior >(node);
2573	BspNode *next;
2574
2575	BspNodeGeometry geom;
2576	// todo: not very efficient: constructs full cell everytime
2577	ConstructGeometry(interior, geom);
2578
2579	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2580	halfspace,
2581	mEpsilon);
2582
2583	if (cf == Polygon3::BACK_SIDE)
2584	next = interior->GetFront();
2585	else
2586	if (cf == Polygon3::FRONT_SIDE)
2587	next = interior->GetFront();
2588	else
2589	{
2590	// random decision
2591	if (mask & 1)
2592	next = interior->GetBack();
2593	else
2594	next = interior->GetFront();
2595	mask = mask >> 1;
2596	}
2597
2598	nodeStack.push(next);
2599	}
2600	}
2601
2602	return NULL;
2603	}
2604
2605
2606	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2607	{
2608	stack<BspNode *> nodeStack;
2609
2610	nodeStack.push(mRoot);
2611
2612	int mask = rand();
2613
2614	while (!nodeStack.empty())
2615	{
2616	BspNode *node = nodeStack.top();
2617	nodeStack.pop();
2618
2619	if (node->IsLeaf())
2620	{
2621	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2622	return dynamic_cast<BspLeaf *>(node);
2623	}
2624	else
2625	{
2626	BspInterior interior = dynamic_cast<BspInterior >(node);
2627
2628	// random decision
2629	if (mask & 1)
2630	nodeStack.push(interior->GetBack());
2631	else
2632	nodeStack.push(interior->GetFront());
2633
2634	mask = mask >> 1;
2635	}
2636	}
2637
2638	return NULL;
2639	}
2640
2641
2642	void BspTree::AddToPvs(BspLeaf *leaf,
2643	const BoundedRayContainer &rays,
2644	int &sampleContributions,
2645	int &contributingSamples)
2646	{
2647	sampleContributions = 0;
2648	contributingSamples = 0;
2649
2650	BoundedRayContainer::const_iterator it, it_end = rays.end();
2651
2652	ViewCell *vc = leaf->GetViewCell();
2653
2654	// add contributions from samples to the PVS
2655	for (it = rays.begin(); it != it_end; ++ it)
2656	{
2657	int contribution = 0;
2658	Ray ray = (it)->mRay;
2659	float relContribution;
2660	if (!ray->intersections.empty())
2661	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2662	1.0f,
2663	relContribution);
2664
2665	if (ray->sourceObject.mObject)
2666	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2667	1.0f,
2668	relContribution);
2669
2670	if (contribution)
2671	{
2672	sampleContributions += contribution;
2673	++ contributingSamples;
2674	}
2675
2676	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2677	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2678	}
2679	}
2680
2681
2682	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2683	{
2684	int pvsSize = 0;
2685
2686	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2687
2688	Intersectable::NewMail();
2689
2690	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2691	{
2692	Ray ray = (rit)->mRay;
2693
2694	if (!ray->intersections.empty())
2695	{
2696	if (!ray->intersections[0].mObject->Mailed())
2697	{
2698	ray->intersections[0].mObject->Mail();
2699	++ pvsSize;
2700	}
2701	}
2702	if (ray->sourceObject.mObject)
2703	{
2704	if (!ray->sourceObject.mObject->Mailed())
2705	{
2706	ray->sourceObject.mObject->Mail();
2707	++ pvsSize;
2708	}
2709	}
2710	}
2711
2712	return pvsSize;
2713	}
2714
2715
2716	float BspTree::GetEpsilon() const
2717	{
2718	return mEpsilon;
2719	}
2720
2721
2722	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2723	vector<MergeCandidate> &candidates)
2724	{
2725	BspLeaf::NewMail();
2726
2727	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2728
2729	int numCandidates = 0;
2730
2731	// find merge candidates and push them into queue
2732	for (it = leaves.begin(); it != it_end; ++ it)
2733	{
2734	BspLeaf leaf = it;
2735
2736	// the same leaves must not be part of two merge candidates
2737	leaf->Mail();
2738	vector<BspLeaf *> neighbors;
2739	FindNeighbors(leaf, neighbors, true);
2740
2741	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2742
2743	// TODO: test if at least one ray goes from one leaf to the other
2744	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2745	{
2746	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2747	{
2748	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2749	candidates.push_back(mc);
2750
2751	++ numCandidates;
2752	if ((numCandidates % 1000) == 0)
2753	{
2754	cout << "collected " << numCandidates << " merge candidates" << endl;
2755	}
2756	}
2757	}
2758	}
2759
2760	Debug << "merge queue: " << (int)candidates.size() << endl;
2761	Debug << "leaves in queue: " << numCandidates << endl;
2762
2763
2764	return (int)leaves.size();
2765	}
2766
2767
2768	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2769	vector<MergeCandidate> &candidates)
2770	{
2771	ViewCell::NewMail();
2772	long startTime = GetTime();
2773
2774	map<BspLeaf , vector<BspLeaf> > neighborMap;
2775	ViewCellContainer::const_iterator iit;
2776
2777	int numLeaves = 0;
2778
2779	BspLeaf::NewMail();
2780
2781	for (int i = 0; i < (int)rays.size(); ++ i)
2782	{
2783	VssRay *ray = rays[i];
2784
2785	// traverse leaves stored in the rays and compare and
2786	// merge consecutive leaves (i.e., the neighbors in the tree)
2787	if (ray->mViewCells.size() < 2)
2788	continue;
2789
2790	iit = ray->mViewCells.begin();
2791	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2792	BspLeaf *leaf = bspVc->mLeaf;
2793
2794	// traverse intersections
2795	// consecutive leaves are neighbors => add them to queue
2796	for (; iit != ray->mViewCells.end(); ++ iit)
2797	{
2798	// next pair
2799	BspLeaf *prevLeaf = leaf;
2800	bspVc = dynamic_cast<BspViewCell >(iit);
2801	leaf = bspVc->mLeaf;
2802
2803	// view space not valid or same view cell
2804	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2805	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2806	continue;
2807
2808	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2809
2810	bool found = false;
2811
2812	// both leaves inserted in queue already =>
2813	// look if double pair already exists
2814	if (leaf->Mailed() && prevLeaf->Mailed())
2815	{
2816	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2817
2818	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2819	if (*it == prevLeaf)
2820	found = true; // already in queue
2821	}
2822
2823	if (!found)
2824	{
2825	// this pair is not in map yet
2826	// => insert into the neighbor map and the queue
2827	neighbors.push_back(prevLeaf);
2828	neighborMap[prevLeaf].push_back(leaf);
2829
2830	leaf->Mail();
2831	prevLeaf->Mail();
2832
2833	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2834
2835	candidates.push_back(mc);
2836
2837	if (((int)candidates.size() % 1000) == 0)
2838	{
2839	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2840	}
2841	}
2842	}
2843	}
2844
2845	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2846	Debug << "merge queue: " << (int)candidates.size() << endl;
2847	Debug << "leaves in queue: " << numLeaves << endl;
2848
2849
2850	//-- collect the leaves which haven't been found by ray casting
2851	#if 0
2852	cout << "finding additional merge candidates using geometry" << endl;
2853	vector<BspLeaf *> leaves;
2854	CollectLeaves(leaves, true);
2855	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2856	CollectMergeCandidates(leaves, candidates);
2857	#endif
2858
2859	return numLeaves;
2860	}
2861
2862
2863
2864
2865	/***************************************************************/
2866	/* BspNodeGeometry Implementation */
2867	/***************************************************************/
2868
2869
2870	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2871	{
2872	mPolys.reserve(rhs.mPolys.size());
2873
2874	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2875	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2876	{
2877	Polygon3 poly = it;
2878	mPolys.push_back(new Polygon3(*poly));
2879	}
2880	}
2881
2882
2883	BspNodeGeometry::~BspNodeGeometry()
2884	{
2885	CLEAR_CONTAINER(mPolys);
2886	}
2887
2888
2889	float BspNodeGeometry::GetArea() const
2890	{
2891	return Polygon3::GetArea(mPolys);
2892	}
2893
2894
2895	float BspNodeGeometry::GetVolume() const
2896	{
2897	//-- compute volume using tetrahedralization of the geometry
2898	// and adding the volume of the single tetrahedrons
2899	float volume = 0;
2900	const float f = 1.0f / 6.0f;
2901
2902	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2903
2904	// note: can take arbitrary point, e.g., the origin. However,
2905	// we rather take the center of mass to prevents precision errors
2906	const Vector3 center = CenterOfMass();
2907
2908	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2909	{
2910	Polygon3 poly = pit;
2911	const Vector3 v0 = poly->mVertices[0] - center;
2912
2913	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2914	{
2915	const Vector3 v1 = poly->mVertices[i] - center;
2916	const Vector3 v2 = poly->mVertices[i + 1] - center;
2917
2918	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2919	}
2920	}
2921
2922	return volume;
2923	}
2924
2925
2926	Vector3 BspNodeGeometry::CenterOfMass() const
2927	{
2928	int n = 0;
2929
2930	Vector3 center(0,0,0);
2931
2932	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2933
2934	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2935	{
2936	Polygon3 poly = pit;
2937
2938	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2939
2940	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2941	{
2942	center += *vit;
2943	++ n;
2944	}
2945	}
2946
2947	return center / (float)n;
2948	}
2949
2950
2951	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2952	{
2953	PolygonContainer::const_iterator it, it_end = mPolys.end();
2954
2955	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2956	{
2957	(*it)->AddToMesh(mesh);
2958	}
2959	}
2960
2961
2962	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2963	BspNodeGeometry &back,
2964	const Plane3 &splitPlane,
2965	const AxisAlignedBox3 &box,
2966	const float epsilon) const
2967	{
2968	// get cross section of new polygon
2969	Polygon3 *planePoly = box.CrossSection(splitPlane);
2970
2971	// split polygon with all other polygons
2972	planePoly = SplitPolygon(planePoly, epsilon);
2973
2974	//-- new polygon splits all other polygons
2975	for (int i = 0; i < (int)mPolys.size(); ++ i)
2976	{
2977	/// don't use epsilon here to get exact split planes
2978	const int cf =
2979	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2980
2981	switch (cf)
2982	{
2983	case Polygon3::SPLIT:
2984	{
2985	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2986
2987	Polygon3 *frontPoly = new Polygon3();
2988	Polygon3 *backPoly = new Polygon3();
2989
2990	poly->Split(splitPlane,
2991	*frontPoly,
2992	*backPoly,
2993	epsilon);
2994
2995	DEL_PTR(poly);
2996
2997	if (frontPoly->Valid(epsilon))
2998	front.mPolys.push_back(frontPoly);
2999	else
3000	DEL_PTR(frontPoly);
3001
3002	if (backPoly->Valid(epsilon))
3003	back.mPolys.push_back(backPoly);
3004	else
3005	DEL_PTR(backPoly);
3006	}
3007
3008	break;
3009	case Polygon3::BACK_SIDE:
3010	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3011	break;
3012	case Polygon3::FRONT_SIDE:
3013	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3014	break;
3015	case Polygon3::COINCIDENT:
3016	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
3017	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3018	break;
3019	default:
3020	break;
3021	}
3022	}
3023
3024	//-- finally add the new polygon to the child node geometries
3025	if (planePoly)
3026	{
3027	// add polygon with normal pointing into positive half space to back cell
3028	back.mPolys.push_back(planePoly);
3029	// add polygon with reverse orientation to front cell
3030	front.mPolys.push_back(planePoly->CreateReversePolygon());
3031	}
3032	}
3033
3034
3035	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3036	const float epsilon) const
3037	{
3038	if (!planePoly->Valid(epsilon))
3039	DEL_PTR(planePoly);
3040
3041	// polygon is split by all other planes
3042	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3043	{
3044	Plane3 plane = mPolys[i]->GetSupportingPlane();
3045
3046	/// don't use epsilon here to get exact split planes
3047	const int cf =
3048	planePoly->ClassifyPlane(plane, Limits::Small);
3049
3050	// split new polygon with all previous planes
3051	switch (cf)
3052	{
3053	case Polygon3::SPLIT:
3054	{
3055	Polygon3 *frontPoly = new Polygon3();
3056	Polygon3 *backPoly = new Polygon3();
3057
3058	planePoly->Split(plane,
3059	*frontPoly,
3060	*backPoly,
3061	epsilon);
3062
3063	// don't need anymore
3064	DEL_PTR(planePoly);
3065	DEL_PTR(frontPoly);
3066
3067	// back polygon is belonging to geometry
3068	if (backPoly->Valid(epsilon))
3069	planePoly = backPoly;
3070	else
3071	DEL_PTR(backPoly);
3072	}
3073	break;
3074	case Polygon3::FRONT_SIDE:
3075	DEL_PTR(planePoly);
3076	break;
3077	// polygon is taken as it is
3078	case Polygon3::BACK_SIDE:
3079	case Polygon3::COINCIDENT:
3080	default:
3081	break;
3082	}
3083	}
3084
3085	return planePoly;
3086	}
3087
3088
3089	ViewCell *
3090	BspTree::GetViewCell(const Vector3 &point)
3091	{
3092	if (mRoot == NULL)
3093	return NULL;
3094
3095
3096	stack<BspNode *> nodeStack;
3097	nodeStack.push(mRoot);
3098
3099	ViewCell *viewcell = NULL;
3100
3101	while (!nodeStack.empty()) {
3102	BspNode *node = nodeStack.top();
3103	nodeStack.pop();
3104
3105	if (node->IsLeaf()) {
3106	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3107	break;
3108	} else {
3109
3110	BspInterior interior = dynamic_cast<BspInterior >(node);
3111
3112	// random decision
3113	if (interior->GetPlane().Side(point) < 0)
3114	nodeStack.push(interior->GetBack());
3115	else
3116	nodeStack.push(interior->GetFront());
3117	}
3118	}
3119
3120	return viewcell;
3121	}
3122
3123
3124	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
3125	{
3126	Polygon3::IncludeInBox(mPolys, box);
3127	}
3128
3129
3130	bool BspTree::Export(ofstream &stream)
3131	{
3132	ExportNode(mRoot, stream);
3133
3134	return true;
3135	}
3136
3137
3138	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3139	{
3140	if (node->IsLeaf())
3141	{
3142	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3143
3144	int id = -1;
3145	if (leaf->GetViewCell() != mOutOfBoundsCell)
3146	id = leaf->GetViewCell()->GetId();
3147
3148	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3149	}
3150	else
3151	{
3152	BspInterior interior = dynamic_cast<BspInterior >(node);
3153
3154	Plane3 plane = interior->GetPlane();
3155	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3156	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3157	<< plane.mD << "\">" << endl;
3158
3159	ExportNode(interior->GetBack(), stream);
3160	ExportNode(interior->GetFront(), stream);
3161
3162	stream << "</Interior>" << endl;
3163	}
3164	}

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