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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 675

Revision 675, 77.3 KB checked in by mattausch, 18 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include "Triangle3.h"
11	#include "Tetrahedron3.h"
12	#include "ViewCellsManager.h"
13	#include "Exporter.h"
14	#include "Plane3.h"
15	#include <stack>
16
17
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	char subdivisionStatsLog[100];
267	environment->GetStringValue("BspTree.subdivisionStats", subdivisionStatsLog);
268	mSubdivisionStats.open(subdivisionStatsLog);
269
270	Debug << "BSP max depth: " << mTermMaxDepth << endl;
271	Debug << "BSP min PVS: " << mTermMinPvs << endl;
272	Debug << "BSP min probability: " << mTermMinProbability << endl;
273	Debug << "BSP max polys: " << mTermMinPolys << endl;
274	Debug << "BSP max rays: " << mTermMinRays << endl;
275	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
276	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
277
278	Debug << "Split plane strategy: ";
279	if (mSplitPlaneStrategy & RANDOM_POLYGON)
280	Debug << "random polygon ";
281	if (mSplitPlaneStrategy & AXIS_ALIGNED)
282	Debug << "axis aligned ";
283	if (mSplitPlaneStrategy & LEAST_SPLITS)
284	Debug << "least splits ";
285	if (mSplitPlaneStrategy & BALANCED_POLYS)
286	Debug << "balanced polygons ";
287	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
288	Debug << "balanced view cells ";
289	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
290	Debug << "largest polygon area ";
291	if (mSplitPlaneStrategy & VERTICAL_AXIS)
292	Debug << "vertical axis ";
293	if (mSplitPlaneStrategy & BLOCKED_RAYS)
294	Debug << "blocked rays ";
295	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
296	Debug << "least ray splits ";
297	if (mSplitPlaneStrategy & BALANCED_RAYS)
298	Debug << "balanced rays ";
299	if (mSplitPlaneStrategy & PVS)
300	Debug << "pvs";
301
302	Debug << endl;
303	}
304
305
306	const BspTreeStatistics &BspTree::GetStatistics() const
307	{
308	return mStat;
309	}
310
311
312	int BspTree::SplitPolygons(const Plane3 &plane,
313	PolygonContainer &polys,
314	PolygonContainer &frontPolys,
315	PolygonContainer &backPolys,
316	PolygonContainer &coincident) const
317	{
318	int splits = 0;
319
320	#ifdef _Debug
321	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
322	#endif
323
324	PolygonContainer::const_iterator it, it_end = polys.end();
325
326	for (it = polys.begin(); it != polys.end(); ++ it)
327	{
328	Polygon3 poly = it;
329
330	//-- classify polygon
331	const int cf = poly->ClassifyPlane(plane, mEpsilon);
332
333	switch (cf)
334	{
335	case Polygon3::COINCIDENT:
336	coincident.push_back(poly);
337	break;
338	case Polygon3::FRONT_SIDE:
339	frontPolys.push_back(poly);
340	break;
341	case Polygon3::BACK_SIDE:
342	backPolys.push_back(poly);
343	break;
344	case Polygon3::SPLIT:
345	{
346	Polygon3 *front_piece = new Polygon3(poly->mParent);
347	Polygon3 *back_piece = new Polygon3(poly->mParent);
348
349	//-- split polygon into front and back part
350	poly->Split(plane,
351	*front_piece,
352	*back_piece,
353	mEpsilon);
354
355	++ splits; // increase number of splits
356
357	//-- inherit rays from parent polygon for blocked ray criterium
358	poly->InheritRays(front_piece, back_piece);
359
360	// check if polygons still valid
361	if (front_piece->Valid(mEpsilon))
362	frontPolys.push_back(front_piece);
363	else
364	DEL_PTR(front_piece);
365
366	if (back_piece->Valid(mEpsilon))
367	backPolys.push_back(back_piece);
368	else
369	DEL_PTR(back_piece);
370
371	#ifdef _DEBUG
372	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
373	#endif
374	DEL_PTR(poly);
375	}
376	break;
377	default:
378	Debug << "SHOULD NEVER COME HERE\n";
379	break;
380	}
381	}
382
383	return splits;
384	}
385
386
387	void BspTreeStatistics::Print(ostream &app) const
388	{
389	app << "===== BspTree statistics ===============\n";
390
391	app << setprecision(4);
392
393	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
394
395	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
396
397	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
398
399	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
400
401	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
402
403	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
404
405	app << "#N_SPLITS ( Number of splits in axes x y z)\n";
406
407	for (int i = 0; i < 3; ++ i)
408	app << splits[i] << " ";
409	app << endl;
410
411	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
412	<< maxDepthNodes * 100 / (double)Leaves() << endl;
413
414	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
415	<< minPvsNodes * 100 / (double)Leaves() << endl;
416
417	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
418	<< minRaysNodes * 100 / (double)Leaves() << endl;
419
420	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
421	<< maxCostNodes * 100 / (double)Leaves() << endl;
422
423	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
424	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
425
426	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
427	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
428
429	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
430
431	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
432
433	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
434
435	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
436
437	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
438
439	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
440	//app << "#N_PVS: " << pvs << endl;
441
442	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
443	(polys + polySplits) / (double)polys << endl;
444
445	app << "===== END OF BspTree statistics ==========\n";
446	}
447
448
449	BspTree::~BspTree()
450	{
451	DEL_PTR(mRoot);
452
453	// TODO must be deleted if used!!
454	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
455	}
456
457	BspViewCell *BspTree::GetOutOfBoundsCell()
458	{
459	return mOutOfBoundsCell;
460	}
461
462
463	BspNode *BspTree::GetRoot() const
464	{
465	return mRoot;
466	}
467
468	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
469	{
470	if (!mOutOfBoundsCell)
471	{
472	mOutOfBoundsCell = new BspViewCell();
473	mOutOfBoundsCell->SetId(-1);
474	mOutOfBoundsCell->SetValid(false);
475	}
476
477	return mOutOfBoundsCell;
478	}
479
480
481	void BspTree::InsertViewCell(ViewCell *viewCell)
482	{
483	PolygonContainer *polys = new PolygonContainer();
484
485	// don't generate new view cell, insert this one
486	mGenerateViewCells = false;
487	// extract polygons that guide the split process
488	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
489	mBox.Include(viewCell->GetBox()); // add to BSP aabb
490
491	InsertPolygons(polys);
492	}
493
494
495	void BspTree::InsertPolygons(PolygonContainer *polys)
496	{
497	BspTraversalStack tStack;
498
499	// traverse existing tree or create new tree
500	if (!mRoot)
501	mRoot = new BspLeaf();
502
503	tStack.push(BspTraversalData(mRoot,
504	polys,
505	0,
506	mOutOfBoundsCell,
507	new BoundedRayContainer(),
508	0,
509	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
510	new BspNodeGeometry()));
511
512	while (!tStack.empty())
513	{
514	// filter polygons donw the tree
515	BspTraversalData tData = tStack.top();
516	tStack.pop();
517
518	if (!tData.mNode->IsLeaf())
519	{
520	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
521
522	//-- filter view cell polygons down the tree until a leaf is reached
523	if (!tData.mPolygons->empty())
524	{
525	PolygonContainer *frontPolys = new PolygonContainer();
526	PolygonContainer *backPolys = new PolygonContainer();
527	PolygonContainer coincident;
528
529	int splits = 0;
530
531	// split viewcell polygons with respect to split plane
532	splits += SplitPolygons(interior->GetPlane(),
533	*tData.mPolygons,
534	*frontPolys,
535	*backPolys,
536	coincident);
537
538	// extract view cells associated with the split polygons
539	ViewCell *frontViewCell = GetOrCreateOutOfBoundsCell();
540	ViewCell *backViewCell = GetOrCreateOutOfBoundsCell();
541
542	BspTraversalData frontData(interior->GetFront(),
543	frontPolys,
544	tData.mDepth + 1,
545	mOutOfBoundsCell,
546	tData.mRays,
547	tData.mPvs,
548	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
549	new BspNodeGeometry());
550
551	BspTraversalData backData(interior->GetBack(),
552	backPolys,
553	tData.mDepth + 1,
554	mOutOfBoundsCell,
555	tData.mRays,
556	tData.mPvs,
557	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
558	new BspNodeGeometry());
559
560	if (!mGenerateViewCells)
561	{
562	ExtractViewCells(frontData,
563	backData,
564	coincident,
565	interior->mPlane);
566	}
567
568	// don't need coincident polygons anymore
569	CLEAR_CONTAINER(coincident);
570
571	mStat.polySplits += splits;
572
573	// push the children on the stack
574	tStack.push(frontData);
575	tStack.push(backData);
576	}
577
578	// cleanup
579	DEL_PTR(tData.mPolygons);
580	DEL_PTR(tData.mRays);
581	}
582	else
583	{
584	// reached leaf => subdivide current viewcell
585	BspNode *subRoot = Subdivide(tStack, tData);
586	}
587	}
588	}
589
590	int BspTree::AddMeshToPolygons(Mesh *mesh,
591	PolygonContainer &polys,
592	MeshInstance *parent)
593	{
594	FaceContainer::const_iterator fi;
595
596	// copy the face data to polygons
597	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
598	{
599	Polygon3 poly = new Polygon3((fi), mesh);
600
601	if (poly->Valid(mEpsilon))
602	{
603	poly->mParent = parent; // set parent intersectable
604	polys.push_back(poly);
605	}
606	else
607	DEL_PTR(poly);
608	}
609	return (int)mesh->mFaces.size();
610	}
611
612
613	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
614	PolygonContainer &polys,
615	int maxObjects)
616	{
617	int limit = (maxObjects > 0) ?
618	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
619
620	int polysSize = 0;
621
622	for (int i = 0; i < limit; ++ i)
623	{
624	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
625	{
626	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
627	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
628	}
629	}
630
631	return polysSize;
632	}
633
634
635	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
636	PolygonContainer &polys,
637	int maxObjects,
638	bool addToBbox)
639	{
640	int limit = (maxObjects > 0) ?
641	Min((int)objects.size(), maxObjects) : (int)objects.size();
642
643	for (int i = 0; i < limit; ++i)
644	{
645	Intersectable object = objects[i];//it;
646	Mesh *mesh = NULL;
647
648	switch (object->Type()) // extract the meshes
649	{
650	case Intersectable::MESH_INSTANCE:
651	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
652	break;
653	case Intersectable::VIEW_CELL:
654	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
655	break;
656	// TODO: handle transformed mesh instances
657	default:
658	Debug << "intersectable type not supported" << endl;
659	break;
660	}
661
662	if (mesh) // copy the mesh data to polygons
663	{
664	if (addToBbox)
665	{
666	mBox.Include(object->GetBox()); // add to BSP tree aabb
667	}
668
669	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
670	}
671	}
672
673	return (int)polys.size();
674	}
675
676
677	void BspTree::Construct(const ViewCellContainer &viewCells)
678	{
679	mStat.nodes = 1;
680	mBox.Initialize(); // initialise bsp tree bounding box
681
682	// copy view cell meshes into one big polygon soup
683	PolygonContainer *polys = new PolygonContainer();
684	mStat.polys = AddToPolygonSoup(viewCells, *polys);
685
686	// view cells are given
687	mGenerateViewCells = false;
688	// construct tree from the view cell polygons
689	Construct(polys, new BoundedRayContainer());
690	}
691
692
693	void BspTree::Construct(const ObjectContainer &objects)
694	{
695	mStat.nodes = 1;
696	mBox.Initialize(); // initialise bsp tree bounding box
697
698	PolygonContainer *polys = new PolygonContainer();
699
700	mGenerateViewCells = true;
701	// copy mesh instance polygons into one big polygon soup
702	mStat.polys = AddToPolygonSoup(objects, *polys);
703
704	// construct tree from polygon soup
705	Construct(polys, new BoundedRayContainer());
706	}
707
708
709	void BspTree::PreprocessPolygons(PolygonContainer &polys)
710	{
711	// preprocess: throw out polygons coincident to the view space box (not needed)
712	PolygonContainer boxPolys;
713	mBox.ExtractPolys(boxPolys);
714	vector<Plane3> boxPlanes;
715
716	PolygonContainer::iterator pit, pit_end = boxPolys.end();
717
718	// extract planes of box
719	// TODO: can be done more elegantly than first extracting polygons
720	// and take their planes
721	for (pit = boxPolys.begin(); pit != pit_end; ++ pit)
722	{
723	boxPlanes.push_back((*pit)->GetSupportingPlane());
724	}
725
726	pit_end = polys.end();
727
728	for (pit = polys.begin(); pit != pit_end; ++ pit)
729	{
730	vector<Plane3>::const_iterator bit, bit_end = boxPlanes.end();
731
732	for (bit = boxPlanes.begin(); (bit != bit_end) && (*pit); ++ bit)
733	{
734	const int cf = (pit)->ClassifyPlane(bit, mEpsilon);
735
736	if (cf == Polygon3::COINCIDENT)
737	{
738	DEL_PTR(*pit);
739	//Debug << "coincident!!" << endl;
740	}
741	}
742	}
743
744	// remove deleted entries
745	for (int i = 0; i < (int)polys.size(); ++ i)
746	{
747	while (!polys[i] && (i < (int)polys.size()))
748	{
749	swap(polys[i], polys.back());
750	polys.pop_back();
751	}
752	}
753	}
754
755
756
757	void BspTree::Construct(const RayContainer &sampleRays,
758	AxisAlignedBox3 *forcedBoundingBox)
759	{
760	mStat.nodes = 1;
761	mBox.Initialize(); // initialise BSP tree bounding box
762
763	if (forcedBoundingBox)
764	mBox = *forcedBoundingBox;
765
766	PolygonContainer *polys = new PolygonContainer();
767	BoundedRayContainer *rays = new BoundedRayContainer();
768
769	RayContainer::const_iterator rit, rit_end = sampleRays.end();
770
771	// generate view cells
772	mGenerateViewCells = true;
773
774	long startTime = GetTime();
775
776	Debug << "** Extracting polygons from rays **\n";
777
778	std::map<Face , Polygon3 > facePolyMap;
779
780	//-- extract polygons intersected by the rays
781	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
782	{
783	Ray ray = rit;
784
785	// get ray-face intersection. Store polygon representing the rays together
786	// with rays intersecting the face.
787	if (!ray->intersections.empty())
788	{
789	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
790	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
791
792	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
793
794	if (it != facePolyMap.end())
795	{
796	//store rays if needed for heuristics
797	if (mSplitPlaneStrategy & BLOCKED_RAYS)
798	(*it).second->mPiercingRays.push_back(ray);
799	}
800	else
801	{ //store rays if needed for heuristics
802	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
803	poly->mParent = obj;
804	polys->push_back(poly);
805
806	if (mSplitPlaneStrategy & BLOCKED_RAYS)
807	poly->mPiercingRays.push_back(ray);
808
809	facePolyMap[face] = poly;
810	}
811	}
812	}
813
814	facePolyMap.clear();
815
816	// compute bounding box
817	if (!forcedBoundingBox)
818	Polygon3::IncludeInBox(*polys, mBox);
819
820	//-- store rays
821	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
822	{
823	Ray ray = rit;
824	ray->SetId(-1); // reset id
825
826	float minT, maxT;
827	if (mBox.GetRaySegment(*ray, minT, maxT))
828	rays->push_back(new BoundedRay(ray, minT, maxT));
829	}
830
831	// throw out bad polygons
832	PreprocessPolygons(*polys);
833
834	mStat.polys = (int)polys->size();
835
836	Debug << "** Finished polygon extraction **" << endl;
837	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
838	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
839
840	Construct(polys, rays);
841	}
842
843
844	void BspTree::Construct(const ObjectContainer &objects,
845	const RayContainer &sampleRays,
846	AxisAlignedBox3 *forcedBoundingBox)
847	{
848	mStat.nodes = 1;
849	mBox.Initialize(); // initialise BSP tree bounding box
850
851	if (forcedBoundingBox)
852	mBox = *forcedBoundingBox;
853
854	BoundedRayContainer *rays = new BoundedRayContainer();
855	PolygonContainer *polys = new PolygonContainer();
856
857	mGenerateViewCells = true;
858
859	// copy mesh instance polygons into one big polygon soup
860	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
861
862
863	RayContainer::const_iterator rit, rit_end = sampleRays.end();
864
865	//-- store rays
866	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
867	{
868	Ray ray = rit;
869	ray->SetId(-1); // reset id
870
871	float minT, maxT;
872	if (mBox.GetRaySegment(*ray, minT, maxT))
873	rays->push_back(new BoundedRay(ray, minT, maxT));
874	}
875
876	PreprocessPolygons(*polys);
877	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
878	Construct(polys, rays);
879	}
880
881
882	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
883	{
884	BspTraversalStack tStack;
885
886	mRoot = new BspLeaf();
887
888	// constrruct root node geometry
889	BspNodeGeometry *geom = new BspNodeGeometry();
890	ConstructGeometry(mRoot, *geom);
891
892	BspTraversalData tData(mRoot,
893	polys,
894	0,
895	GetOrCreateOutOfBoundsCell(),
896	rays,
897	ComputePvsSize(*rays),
898	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
899	geom);
900
901	mTotalCost = tData.mPvs * tData.mProbability / mBox.GetVolume();
902	mTotalPvsSize = tData.mPvs;
903
904	mSubdivisionStats
905	<< "#ViewCells\n1\n" << endl
906	<< "#RenderCostDecrease\n0\n" << endl
907	<< "#TotalRenderCost\n" << mTotalCost << endl
908	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
909
910	tStack.push(tData);
911
912	// used for intermediate time measurements and progress
913	long interTime = GetTime();
914	int nleaves = 500;
915
916	mStat.Start();
917	cout << "Constructing bsp tree ...\n";
918	long startTime = GetTime();
919	while (!tStack.empty())
920	{
921	tData = tStack.top();
922
923	tStack.pop();
924
925	// subdivide leaf node
926	BspNode *r = Subdivide(tStack, tData);
927
928	if (r == mRoot)
929	Debug << "BSP tree construction time spent at root: "
930	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
931
932	if (mStat.Leaves() >= nleaves)
933	{
934	nleaves += 500;
935
936	cout << "leaves=" << mStat.Leaves() << endl;
937	Debug << "needed "
938	<< TimeDiff(interTime, GetTime())*1e-3
939	<< " secs to create 500 leaves" << endl;
940	interTime = GetTime();
941	}
942	}
943
944	cout << "finished\n";
945
946	mStat.Stop();
947	}
948
949
950	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
951	{
952	return
953	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
954	((int)data.mRays->size() <= mTermMinRays) \|\|
955	(data.mPvs <= mTermMinPvs) \|\|
956	(data.mProbability <= mTermMinProbability) \|\|
957	(data.mDepth >= mTermMaxDepth) \|\|
958	(mStat.Leaves() >= mMaxViewCells) \|\|
959	(data.GetAvgRayContribution() > mTermMaxRayContribution));
960	}
961
962
963	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
964	{
965	//-- terminate traversal
966	if (TerminationCriteriaMet(tData))
967	{
968	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
969
970	BspViewCell *viewCell;
971
972	// generate new view cell for each leaf
973	if (mGenerateViewCells)
974	viewCell = new BspViewCell();
975	else
976	// add view cell to leaf
977	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
978
979	leaf->SetViewCell(viewCell);
980	viewCell->mLeaf = leaf;
981
982	float probability = max(0.0f, tData.mProbability);
983
984	if (mUseAreaForPvs)
985	viewCell->SetArea(probability);
986	else
987	viewCell->SetVolume(probability);
988
989	//-- add pvs
990	if (viewCell != mOutOfBoundsCell)
991	{
992	int conSamp = 0, sampCon = 0;
993	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
994
995	mStat.contributingSamples += conSamp;
996	mStat.sampleContributions += sampCon;
997	}
998
999	EvaluateLeafStats(tData);
1000
1001	//-- clean up
1002
1003	// discard polygons
1004	CLEAR_CONTAINER(*tData.mPolygons);
1005	// discard rays
1006	CLEAR_CONTAINER(*tData.mRays);
1007
1008	DEL_PTR(tData.mPolygons);
1009	DEL_PTR(tData.mRays);
1010	DEL_PTR(tData.mGeometry);
1011
1012	return leaf;
1013	}
1014
1015	//-- continue subdivision
1016	PolygonContainer coincident;
1017
1018	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1019	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1020	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1021	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1022
1023
1024	// create new interior node and two leaf nodes
1025	BspInterior *interior =
1026	SubdivideNode(tData, tFrontData, tBackData, coincident);
1027
1028
1029	if (1)
1030	{
1031	int pvsData = tData.mPvs;
1032
1033	float cData = (float)pvsData * tData.mProbability;
1034	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1035	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1036
1037	float costDecr = (cFront + cBack - cData) / mBox.GetVolume();
1038
1039	mTotalCost += costDecr;
1040	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1041
1042	mSubdivisionStats
1043	<< "#ViewCells\n" << mStat.Leaves() << endl
1044	<< "#RenderCostDecrease\n" << -costDecr << endl
1045	<< "#TotalRenderCost\n" << mTotalCost << endl
1046	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1047	}
1048
1049	// extract view cells from coincident polygons according to plane normal
1050	// only if front or back polygons are empty
1051	if (!mGenerateViewCells)
1052	{
1053	ExtractViewCells(tFrontData,
1054	tBackData,
1055	coincident,
1056	interior->mPlane);
1057	}
1058
1059	// don't need coincident polygons anymory
1060	CLEAR_CONTAINER(coincident);
1061
1062	// push the children on the stack
1063	tStack.push(tFrontData);
1064	tStack.push(tBackData);
1065
1066	// cleanup
1067	DEL_PTR(tData.mNode);
1068
1069	DEL_PTR(tData.mPolygons);
1070	DEL_PTR(tData.mRays);
1071	DEL_PTR(tData.mGeometry);
1072
1073	return interior;
1074	}
1075
1076
1077	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1078	BspTraversalData &backData,
1079	const PolygonContainer &coincident,
1080	const Plane3 &splitPlane) const
1081	{
1082	// if not empty, tree is further subdivided => don't have to find view cell
1083	bool foundFront = !frontData.mPolygons->empty();
1084	bool foundBack = !frontData.mPolygons->empty();
1085
1086	PolygonContainer::const_iterator it =
1087	coincident.begin(), it_end = coincident.end();
1088
1089	//-- find first view cells in front and back leafs
1090	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1091	{
1092	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1093	{
1094	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1095	foundBack = true;
1096	}
1097	else
1098	{
1099	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1100	foundFront = true;
1101	}
1102	}
1103	}
1104
1105
1106	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1107	BspTraversalData &frontData,
1108	BspTraversalData &backData,
1109	PolygonContainer &coincident)
1110	{
1111	mStat.nodes += 2;
1112
1113	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1114
1115
1116
1117	// select subdivision plane
1118	BspInterior *interior =
1119	new BspInterior(SelectPlane(leaf, tData));
1120
1121
1122	#ifdef _DEBUG
1123	Debug << interior << endl;
1124	#endif
1125
1126
1127	// subdivide rays into front and back rays
1128	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1129
1130
1131
1132	// subdivide polygons with plane
1133	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1134	*tData.mPolygons,
1135	*frontData.mPolygons,
1136	*backData.mPolygons,
1137	coincident);
1138
1139
1140
1141	// compute pvs
1142	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1143	backData.mPvs = ComputePvsSize(*backData.mRays);
1144
1145	// split geometry and compute area
1146	if (1)
1147	{
1148	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1149	*backData.mGeometry,
1150	interior->mPlane,
1151	mBox,
1152	//0.000000000001);
1153	mEpsilon);
1154
1155
1156	if (mUseAreaForPvs)
1157	{
1158	frontData.mProbability = frontData.mGeometry->GetArea();
1159	backData.mProbability = backData.mGeometry->GetArea();
1160	}
1161	else
1162	{
1163	frontData.mProbability = frontData.mGeometry->GetVolume();
1164	backData.mProbability = tData.mProbability - frontData.mProbability;
1165	}
1166	}
1167
1168	//-- create front and back leaf
1169
1170	BspInterior *parent = leaf->GetParent();
1171
1172	// replace a link from node's parent
1173	if (!leaf->IsRoot())
1174	{
1175	parent->ReplaceChildLink(leaf, interior);
1176	interior->SetParent(parent);
1177	}
1178	else // new root
1179	{
1180	mRoot = interior;
1181	}
1182
1183	// and setup child links
1184	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1185
1186	frontData.mNode = interior->GetFront();
1187	backData.mNode = interior->GetBack();
1188
1189	interior->mTimeStamp = mTimeStamp ++;
1190
1191	//DEL_PTR(leaf);
1192	return interior;
1193	}
1194
1195
1196	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1197	const int axis,
1198	vector<SortableEntry> &splitCandidates) const
1199	{
1200	splitCandidates.clear();
1201
1202	int requestedSize = 2 * (int)polys.size();
1203	// creates a sorted split candidates array
1204	splitCandidates.reserve(requestedSize);
1205
1206	PolygonContainer::const_iterator it, it_end = polys.end();
1207
1208	AxisAlignedBox3 box;
1209
1210	// insert all queries
1211	for(it = polys.begin(); it != it_end; ++ it)
1212	{
1213	box.Initialize();
1214	box.Include((it));
1215
1216	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1217	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1218	}
1219
1220	stable_sort(splitCandidates.begin(), splitCandidates.end());
1221	}
1222
1223
1224	float BspTree::BestCostRatio(const PolygonContainer &polys,
1225	const AxisAlignedBox3 &box,
1226	const int axis,
1227	float &position,
1228	int &objectsBack,
1229	int &objectsFront) const
1230	{
1231	vector<SortableEntry> splitCandidates;
1232
1233	SortSplitCandidates(polys, axis, splitCandidates);
1234
1235	// go through the lists, count the number of objects left and right
1236	// and evaluate the following cost funcion:
1237	// C = ct_div_ci + (ol + or)/queries
1238
1239	int objectsLeft = 0, objectsRight = (int)polys.size();
1240
1241	float minBox = box.Min(axis);
1242	float maxBox = box.Max(axis);
1243	float boxArea = box.SurfaceArea();
1244
1245	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1246	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1247
1248	float minSum = 1e20f;
1249	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1250
1251	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1252	{
1253	switch ((*ci).type)
1254	{
1255	case SortableEntry::POLY_MIN:
1256	++ objectsLeft;
1257	break;
1258	case SortableEntry::POLY_MAX:
1259	-- objectsRight;
1260	break;
1261	default:
1262	break;
1263	}
1264
1265	if ((ci).value > minBand && (ci).value < maxBand)
1266	{
1267	AxisAlignedBox3 lbox = box;
1268	AxisAlignedBox3 rbox = box;
1269	lbox.SetMax(axis, (*ci).value);
1270	rbox.SetMin(axis, (*ci).value);
1271
1272	const float sum = objectsLeft * lbox.SurfaceArea() +
1273	objectsRight * rbox.SurfaceArea();
1274
1275	if (sum < minSum)
1276	{
1277	minSum = sum;
1278	position = (*ci).value;
1279
1280	objectsBack = objectsLeft;
1281	objectsFront = objectsRight;
1282	}
1283	}
1284	}
1285
1286	const float oldCost = (float)polys.size();
1287	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1288	const float ratio = newCost / oldCost;
1289
1290
1291	#if 0
1292	Debug << "====================" << endl;
1293	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1294	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1295	#endif
1296	return ratio;
1297	}
1298
1299	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1300	const PolygonContainer &polys) const
1301	{
1302	AxisAlignedBox3 box;
1303	box.Initialize();
1304
1305	// create bounding box of region
1306	Polygon3::IncludeInBox(polys, box);
1307
1308	int objectsBack = 0, objectsFront = 0;
1309	int axis = 0;
1310	float costRatio = MAX_FLOAT;
1311	Vector3 position;
1312
1313	//-- area subdivision
1314	for (int i = 0; i < 3; ++ i)
1315	{
1316	float p = 0;
1317	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1318
1319	if (r < costRatio)
1320	{
1321	costRatio = r;
1322	axis = i;
1323	position = p;
1324	}
1325	}
1326
1327	if (costRatio >= mMaxCostRatio)
1328	return false;
1329
1330	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1331	plane = Plane3(norm, position);
1332
1333	return true;
1334	}
1335
1336
1337	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1338	{
1339	if ((!mMaxPolyCandidates \|\| data.mPolygons->empty()) &&
1340	(!mMaxRayCandidates \|\| data.mRays->empty()))
1341	{
1342	Debug << "Warning: No autopartition polygon candidate available\n";
1343
1344	// return axis aligned split
1345	AxisAlignedBox3 box;
1346	box.Initialize();
1347
1348	// create bounding box of region
1349	Polygon3::IncludeInBox(*data.mPolygons, box);
1350
1351	const int axis = box.Size().DrivingAxis();
1352	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1353
1354	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1355	return Plane3(norm, position);
1356	}
1357
1358	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1359	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1360	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1361	((mTermMinObjectsForAxisAligned < 0) \|\|
1362	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1363	{
1364	Plane3 plane;
1365	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1366	return plane;
1367	}
1368
1369	// simplest strategy: just take next polygon
1370	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1371	{
1372	if (!data.mPolygons->empty())
1373	{
1374	Polygon3 *nextPoly =
1375	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1376	return nextPoly->GetSupportingPlane();
1377	}
1378	else
1379	{
1380	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1381	BoundedRay bRay = (data.mRays)[candidateIdx];
1382
1383	Ray *ray = bRay->mRay;
1384
1385	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1386	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1387
1388	const Vector3 pt = (maxPt + minPt) * 0.5;
1389
1390	const Vector3 normal = ray->GetDir();
1391
1392	return Plane3(normal, pt);
1393	}
1394
1395	return Plane3();
1396	}
1397
1398	// use heuristics to find appropriate plane
1399	return SelectPlaneHeuristics(leaf, data);
1400	}
1401
1402
1403	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1404	{
1405	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1406	BoundedRay *bRay = rays[candidateIdx];
1407	Ray *ray = bRay->mRay;
1408
1409	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1410	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1411
1412	const Vector3 pt = (maxPt + minPt) * 0.5;
1413
1414	const Vector3 normal = ray->GetDir();
1415
1416	return Plane3(normal, pt);
1417	}
1418
1419	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1420	{
1421	Vector3 pt[3];
1422	int idx[3];
1423	int cmaxT = 0;
1424	int cminT = 0;
1425	bool chooseMin = false;
1426
1427	for (int j = 0; j < 3; j ++)
1428	{
1429	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1430
1431	if (idx[j] >= (int)rays.size())
1432	{
1433	idx[j] -= (int)rays.size();
1434	chooseMin = (cminT < 2);
1435	}
1436	else
1437	chooseMin = (cmaxT < 2);
1438
1439	BoundedRay *bRay = rays[idx[j]];
1440	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1441	bRay->mRay->Extrap(bRay->mMaxT);
1442	}
1443
1444	return Plane3(pt[0], pt[1], pt[2]);
1445	}
1446
1447	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1448	{
1449	Vector3 pt[3];
1450
1451	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1452	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1453
1454	// check if rays different
1455	if (idx1 == idx2)
1456	idx2 = (idx2 + 1) % (int)rays.size();
1457
1458	const BoundedRay *ray1 = rays[idx1];
1459	const BoundedRay *ray2 = rays[idx2];
1460
1461	// normal vector of the plane parallel to both lines
1462	const Vector3 norm =
1463	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1464
1465	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1466	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1467
1468	// vector from line 1 to line 2
1469	const Vector3 vd = orig1 - orig2;
1470
1471	// project vector on normal to get distance
1472	const float dist = DotProd(vd, norm);
1473
1474	// point on plane lies halfway between the two planes
1475	const Vector3 planePt = orig1 + norm * dist * 0.5;
1476
1477	return Plane3(norm, planePt);
1478	}
1479
1480
1481	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1482	{
1483	float lowestCost = MAX_FLOAT;
1484	Plane3 bestPlane;
1485	// intermediate plane
1486	Plane3 plane;
1487
1488	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1489	int maxIdx = (int)data.mPolygons->size();
1490
1491	for (int i = 0; i < limit; ++ i)
1492	{
1493	// assure that no index is taken twice
1494	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1495
1496	Polygon3 poly = (data.mPolygons)[candidateIdx];
1497
1498	// swap candidate to the end to avoid testing same plane
1499	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1500	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1501
1502	// evaluate current candidate
1503	const float candidateCost =
1504	SplitPlaneCost(poly->GetSupportingPlane(), data);
1505
1506	if (candidateCost < lowestCost)
1507	{
1508	bestPlane = poly->GetSupportingPlane();
1509	lowestCost = candidateCost;
1510	}
1511	}
1512
1513	//-- choose candidate planes extracted from rays
1514	for (int i = 0; i < mMaxRayCandidates; ++ i)
1515	{
1516	plane = ChooseCandidatePlane3(*data.mRays);
1517	const float candidateCost = SplitPlaneCost(plane, data);
1518
1519	if (candidateCost < lowestCost)
1520	{
1521	bestPlane = plane;
1522	lowestCost = candidateCost;
1523	}
1524	}
1525
1526	#ifdef _DEBUG
1527	Debug << "plane lowest cost: " << lowestCost << endl;
1528	#endif
1529
1530	return bestPlane;
1531	}
1532
1533
1534	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1535	const PolygonContainer &polys) const
1536	{
1537	float val = 0;
1538
1539	float sumBalancedPolys = 0;
1540	float sumSplits = 0;
1541	float sumPolyArea = 0;
1542	float sumBalancedViewCells = 0;
1543	float sumBlockedRays = 0;
1544	float totalBlockedRays = 0;
1545	//float totalArea = 0;
1546	int totalViewCells = 0;
1547
1548	// need three unique ids for each type of view cell
1549	// for balanced view cells criterium
1550	ViewCell::NewMail();
1551	const int backId = ViewCell::sMailId;
1552	ViewCell::NewMail();
1553	const int frontId = ViewCell::sMailId;
1554	ViewCell::NewMail();
1555	const int frontAndBackId = ViewCell::sMailId;
1556
1557	bool useRand;
1558	int limit;
1559
1560	// choose test polyongs randomly if over threshold
1561	if ((int)polys.size() > mMaxTests)
1562	{
1563	useRand = true;
1564	limit = mMaxTests;
1565	}
1566	else
1567	{
1568	useRand = false;
1569	limit = (int)polys.size();
1570	}
1571
1572	for (int i = 0; i < limit; ++ i)
1573	{
1574	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1575
1576	Polygon3 *poly = polys[testIdx];
1577
1578	const int classification =
1579	poly->ClassifyPlane(candidatePlane, mEpsilon);
1580
1581	if (mSplitPlaneStrategy & BALANCED_POLYS)
1582	sumBalancedPolys += sBalancedPolysTable[classification];
1583
1584	if (mSplitPlaneStrategy & LEAST_SPLITS)
1585	sumSplits += sLeastPolySplitsTable[classification];
1586
1587	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1588	{
1589	if (classification == Polygon3::COINCIDENT)
1590	sumPolyArea += poly->GetArea();
1591	//totalArea += area;
1592	}
1593
1594	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1595	{
1596	const float blockedRays = (float)poly->mPiercingRays.size();
1597
1598	if (classification == Polygon3::COINCIDENT)
1599	sumBlockedRays += blockedRays;
1600
1601	totalBlockedRays += blockedRays;
1602	}
1603
1604	// assign view cells to back or front according to classificaion
1605	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1606	{
1607	MeshInstance *viewCell = poly->mParent;
1608
1609	// assure that we only count a view cell
1610	// once for the front and once for the back side of the plane
1611	if (classification == Polygon3::FRONT_SIDE)
1612	{
1613	if ((viewCell->mMailbox != frontId) &&
1614	(viewCell->mMailbox != frontAndBackId))
1615	{
1616	sumBalancedViewCells += 1.0;
1617
1618	if (viewCell->mMailbox != backId)
1619	viewCell->mMailbox = frontId;
1620	else
1621	viewCell->mMailbox = frontAndBackId;
1622
1623	++ totalViewCells;
1624	}
1625	}
1626	else if (classification == Polygon3::BACK_SIDE)
1627	{
1628	if ((viewCell->mMailbox != backId) &&
1629	(viewCell->mMailbox != frontAndBackId))
1630	{
1631	sumBalancedViewCells -= 1.0;
1632
1633	if (viewCell->mMailbox != frontId)
1634	viewCell->mMailbox = backId;
1635	else
1636	viewCell->mMailbox = frontAndBackId;
1637
1638	++ totalViewCells;
1639	}
1640	}
1641	}
1642	}
1643
1644	const float polysSize = (float)polys.size() + Limits::Small;
1645
1646	// all values should be approx. between 0 and 1 so they can be combined
1647	// and scaled with the factors according to their importance
1648	if (mSplitPlaneStrategy & BALANCED_POLYS)
1649	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1650
1651	if (mSplitPlaneStrategy & LEAST_SPLITS)
1652	val += mLeastSplitsFactor * sumSplits / polysSize;
1653
1654	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1655	// HACK: polys.size should be total area so scaling is between 0 and 1
1656	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1657
1658	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1659	if (totalBlockedRays != 0)
1660	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1661
1662	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1663	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1664	((float)totalViewCells + Limits::Small);
1665
1666	return val;
1667	}
1668
1669
1670	inline void BspTree::GenerateUniqueIdsForPvs()
1671	{
1672	ViewCell::NewMail(); sBackId = ViewCell::sMailId;
1673	ViewCell::NewMail(); sFrontId = ViewCell::sMailId;
1674	ViewCell::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1675	}
1676
1677
1678	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1679	const BoundedRayContainer &rays,
1680	const int pvs,
1681	const float probability,
1682	const BspNodeGeometry &cell) const
1683	{
1684	float val = 0;
1685
1686	float sumBalancedRays = 0;
1687	float sumRaySplits = 0;
1688
1689	int frontPvs = 0;
1690	int backPvs = 0;
1691
1692	// probability that view point lies in child
1693	float pOverall = 0;
1694	float pFront = 0;
1695	float pBack = 0;
1696
1697	const bool pvsUseLen = false;
1698
1699	if (mSplitPlaneStrategy & PVS)
1700	{
1701	// create unique ids for pvs heuristics
1702	GenerateUniqueIdsForPvs();
1703
1704	// construct child geometry with regard to the candidate split plane
1705	BspNodeGeometry frontCell;
1706	BspNodeGeometry backCell;
1707
1708	cell.SplitGeometry(frontCell,
1709	backCell,
1710	candidatePlane,
1711	mBox,
1712	mEpsilon);
1713
1714	if (mUseAreaForPvs)
1715	{
1716	pFront = frontCell.GetArea();
1717	pBack = backCell.GetArea();
1718	}
1719	else
1720	{
1721	pFront = frontCell.GetVolume();
1722	pBack = pOverall - pFront;
1723	}
1724
1725
1726	pOverall = probability;
1727	}
1728
1729	bool useRand;
1730	int limit;
1731
1732	// choose test polyongs randomly if over threshold
1733	if ((int)rays.size() > mMaxTests)
1734	{
1735	useRand = true;
1736	limit = mMaxTests;
1737	}
1738	else
1739	{
1740	useRand = false;
1741	limit = (int)rays.size();
1742	}
1743
1744	for (int i = 0; i < limit; ++ i)
1745	{
1746	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1747
1748	BoundedRay *bRay = rays[testIdx];
1749
1750	Ray *ray = bRay->mRay;
1751	const float minT = bRay->mMinT;
1752	const float maxT = bRay->mMaxT;
1753
1754	Vector3 entP, extP;
1755
1756	const int cf =
1757	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1758
1759	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1760	{
1761	sumBalancedRays += sBalancedRaysTable[cf];
1762	}
1763
1764	if (mSplitPlaneStrategy & BALANCED_RAYS)
1765	{
1766	sumRaySplits += sLeastRaySplitsTable[cf];
1767	}
1768
1769	if (mSplitPlaneStrategy & PVS)
1770	{
1771	// in case the ray intersects an object
1772	// assure that we only count the object
1773	// once for the front and once for the back side of the plane
1774
1775	// add the termination object
1776	if (!ray->intersections.empty())
1777	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1778
1779	// add the source object
1780	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1781	}
1782	}
1783
1784	const float raysSize = (float)rays.size() + Limits::Small;
1785
1786	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1787	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1788
1789	if (mSplitPlaneStrategy & BALANCED_RAYS)
1790	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1791
1792	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1793
1794	if (mSplitPlaneStrategy & PVS)
1795	{
1796	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1797
1798	// give penalty to unbalanced split
1799	if (0)
1800	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1801	(pFront < (pBack * 0.2 + Limits::Small)))
1802	val += 0.5;
1803	}
1804
1805
1806	#ifdef _DEBUG
1807	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1808	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1809	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1810	#endif
1811
1812	return val;
1813	}
1814
1815	void BspTree::AddObjToPvs(Intersectable *obj,
1816	const int cf,
1817	int &frontPvs,
1818	int &backPvs) const
1819	{
1820	if (!obj)
1821	return;
1822	// TODO: does this really belong to no pvs?
1823	//if (cf == Ray::COINCIDENT) return;
1824
1825	// object belongs to both PVS
1826	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1827	(cf == Ray::BACK_FRONT) \|\|
1828	(cf == Ray::COINCIDENT);
1829
1830	if ((cf == Ray::FRONT) \|\| bothSides)
1831	{
1832	if ((obj->mMailbox != sFrontId) &&
1833	(obj->mMailbox != sFrontAndBackId))
1834	{
1835	++ frontPvs;
1836
1837	if (obj->mMailbox == sBackId)
1838	obj->mMailbox = sFrontAndBackId;
1839	else
1840	obj->mMailbox = sFrontId;
1841	}
1842	}
1843
1844	if ((cf == Ray::BACK) \|\| bothSides)
1845	{
1846	if ((obj->mMailbox != sBackId) &&
1847	(obj->mMailbox != sFrontAndBackId))
1848	{
1849	++ backPvs;
1850
1851	if (obj->mMailbox == sFrontId)
1852	obj->mMailbox = sFrontAndBackId;
1853	else
1854	obj->mMailbox = sBackId;
1855	}
1856	}
1857	}
1858
1859
1860	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1861	BspTraversalData &data) const
1862	{
1863	float val = 0;
1864
1865	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1866	{
1867	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1868	// we put a penalty on the dot product between the "tiny" vertical axis
1869	// and the split plane axis
1870	val += mVerticalSplitsFactor *
1871	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1872	}
1873
1874	// the following criteria loop over all polygons to find the cost value
1875	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1876	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1877	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1878	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1879	(mSplitPlaneStrategy & BLOCKED_RAYS))
1880	{
1881	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1882	}
1883
1884	// the following criteria loop over all rays to find the cost value
1885	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1886	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1887	(mSplitPlaneStrategy & PVS))
1888	{
1889	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1890	data.mProbability, *data.mGeometry);
1891	}
1892
1893	// return linear combination of the sums
1894	return val;
1895	}
1896
1897	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1898	{
1899	stack<BspNode *> nodeStack;
1900	nodeStack.push(mRoot);
1901
1902	while (!nodeStack.empty())
1903	{
1904	BspNode *node = nodeStack.top();
1905
1906	nodeStack.pop();
1907
1908	if (node->IsLeaf())
1909	{
1910	BspLeaf leaf = (BspLeaf )node;
1911	leaves.push_back(leaf);
1912	}
1913	else
1914	{
1915	BspInterior interior = dynamic_cast<BspInterior >(node);
1916
1917	nodeStack.push(interior->GetBack());
1918	nodeStack.push(interior->GetFront());
1919	}
1920	}
1921	}
1922
1923
1924	AxisAlignedBox3 BspTree::GetBoundingBox() const
1925	{
1926	return mBox;
1927	}
1928
1929
1930	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1931	{
1932	// the node became a leaf -> evaluate stats for leafs
1933	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1934
1935	// store maximal and minimal depth
1936	if (data.mDepth > mStat.maxDepth)
1937	mStat.maxDepth = data.mDepth;
1938
1939	if (data.mDepth < mStat.minDepth)
1940	mStat.minDepth = data.mDepth;
1941
1942	// accumulate depth to compute average depth
1943	mStat.accumDepth += data.mDepth;
1944	// accumulate rays to compute rays / leaf
1945	mStat.accumRays += (int)data.mRays->size();
1946
1947	if (data.mDepth >= mTermMaxDepth)
1948	++ mStat.maxDepthNodes;
1949
1950	if (data.mPvs < mTermMinPvs)
1951	++ mStat.minPvsNodes;
1952
1953	if ((int)data.mRays->size() < mTermMinRays)
1954	++ mStat.minRaysNodes;
1955
1956	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1957	++ mStat.maxRayContribNodes;
1958
1959	if (data.mProbability <= mTermMinProbability)
1960	++ mStat.minProbabilityNodes;
1961
1962	#ifdef _DEBUG
1963	Debug << "BSP stats: "
1964	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1965	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1966	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
1967	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1968	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1969	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1970	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1971	#endif
1972	}
1973
1974	int
1975	BspTree::_CastRay(Ray &ray)
1976	{
1977	int hits = 0;
1978
1979	stack<BspRayTraversalData> tStack;
1980
1981	float maxt, mint;
1982
1983	if (!mBox.GetRaySegment(ray, mint, maxt))
1984	return 0;
1985
1986	ViewCell::NewMail();
1987
1988	Vector3 entp = ray.Extrap(mint);
1989	Vector3 extp = ray.Extrap(maxt);
1990
1991	BspNode *node = mRoot;
1992	BspNode *farChild = NULL;
1993
1994	while (1)
1995	{
1996	if (!node->IsLeaf())
1997	{
1998	BspInterior in = dynamic_cast<BspInterior >(node);
1999
2000	Plane3 splitPlane = in->GetPlane();
2001	const int entSide = splitPlane.Side(entp);
2002	const int extSide = splitPlane.Side(extp);
2003
2004	if (entSide < 0)
2005	{
2006	node = in->GetBack();
2007
2008	if(extSide <= 0) // plane does not split ray => no far child
2009	continue;
2010
2011	farChild = in->GetFront(); // plane splits ray
2012
2013	} else if (entSide > 0)
2014	{
2015	node = in->GetFront();
2016
2017	if (extSide >= 0) // plane does not split ray => no far child
2018	continue;
2019
2020	farChild = in->GetBack(); // plane splits ray
2021	}
2022	else // ray and plane are coincident
2023	{
2024	// WHAT TO DO IN THIS CASE ?
2025	//break;
2026	node = in->GetFront();
2027	continue;
2028	}
2029
2030	// push data for far child
2031	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2032
2033	// find intersection of ray segment with plane
2034	float t;
2035	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
2036	maxt *= t;
2037
2038	} else // reached leaf => intersection with view cell
2039	{
2040	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2041
2042	if (!leaf->mViewCell->Mailed())
2043	{
2044	//ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
2045	leaf->mViewCell->Mail();
2046	++ hits;
2047	}
2048
2049	//-- fetch the next far child from the stack
2050	if (tStack.empty())
2051	break;
2052
2053	entp = extp;
2054	mint = maxt; // NOTE: need this?
2055
2056	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
2057	break;
2058
2059	BspRayTraversalData &s = tStack.top();
2060
2061	node = s.mNode;
2062	extp = s.mExitPoint;
2063	maxt = s.mMaxT;
2064
2065	tStack.pop();
2066	}
2067	}
2068
2069	return hits;
2070	}
2071
2072
2073	int BspTree::CastLineSegment(const Vector3 &origin,
2074	const Vector3 &termination,
2075	vector<ViewCell *> &viewcells)
2076	{
2077	int hits = 0;
2078	stack<BspRayTraversalData> tStack;
2079
2080	float mint = 0.0f, maxt = 1.0f;
2081
2082	Intersectable::NewMail();
2083	ViewCell::NewMail();
2084
2085	Vector3 entp = origin;
2086	Vector3 extp = termination;
2087
2088	BspNode *node = mRoot;
2089	BspNode *farChild = NULL;
2090
2091	const float thresh = 1 ? 1e-6f : 0.0f;
2092
2093	while (1)
2094	{
2095	if (!node->IsLeaf())
2096	{
2097	BspInterior in = dynamic_cast<BspInterior >(node);
2098
2099	Plane3 splitPlane = in->GetPlane();
2100
2101	const int entSide = splitPlane.Side(entp, thresh);
2102	const int extSide = splitPlane.Side(extp, thresh);
2103
2104	if (entSide < 0)
2105	{
2106	node = in->GetBack();
2107
2108	if(extSide <= 0) // plane does not split ray => no far child
2109	continue;
2110
2111	farChild = in->GetFront(); // plane splits ray
2112
2113	}
2114	else if (entSide > 0)
2115	{
2116	node = in->GetFront();
2117
2118	if (extSide >= 0) // plane does not split ray => no far child
2119	continue;
2120
2121	farChild = in->GetBack(); // plane splits ray
2122	}
2123	else // ray and plane are coincident
2124	{
2125	// NOTE: what to do if ray is coincident with plane?
2126	if (extSide < 0)
2127	node = in->GetBack();
2128	else
2129	node = in->GetFront();
2130
2131	continue; // no far child
2132	}
2133
2134	// push data for far child
2135	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2136
2137	// find intersection of ray segment with plane
2138	float t;
2139	extp = splitPlane.FindIntersection(origin, extp, &t);
2140	maxt *= t;
2141	}
2142	else
2143	{
2144	// reached leaf => intersection with view cell
2145	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2146
2147	if (!leaf->mViewCell->Mailed())
2148	{
2149	viewcells.push_back(leaf->mViewCell);
2150	leaf->mViewCell->Mail();
2151	hits++;
2152	}
2153
2154	//-- fetch the next far child from the stack
2155	if (tStack.empty())
2156	break;
2157
2158	entp = extp;
2159	mint = maxt; // NOTE: need this?
2160
2161	BspRayTraversalData &s = tStack.top();
2162
2163	node = s.mNode;
2164	extp = s.mExitPoint;
2165	maxt = s.mMaxT;
2166
2167	tStack.pop();
2168	}
2169	}
2170	return hits;
2171	}
2172
2173
2174	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2175	{
2176	stack<BspNode *> nodeStack;
2177	nodeStack.push(mRoot);
2178
2179	ViewCell::NewMail();
2180
2181	while (!nodeStack.empty())
2182	{
2183	BspNode *node = nodeStack.top();
2184	nodeStack.pop();
2185
2186	if (node->IsLeaf())
2187	{
2188	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2189
2190	if (!viewCell->Mailed())
2191	{
2192	viewCell->Mail();
2193	viewCells.push_back(viewCell);
2194	}
2195	}
2196	else
2197	{
2198	BspInterior interior = dynamic_cast<BspInterior >(node);
2199
2200	nodeStack.push(interior->GetFront());
2201	nodeStack.push(interior->GetBack());
2202	}
2203	}
2204	}
2205
2206
2207	BspTreeStatistics &BspTree::GetStat()
2208	{
2209	return mStat;
2210	}
2211
2212
2213	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2214	{
2215	float len = 0;
2216
2217	BoundedRayContainer::const_iterator it, it_end = rays.end();
2218
2219	for (it = rays.begin(); it != it_end; ++ it)
2220	{
2221	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2222	(it)->mRay->Extrap((it)->mMaxT));
2223	}
2224
2225	return len;
2226	}
2227
2228
2229	int BspTree::SplitRays(const Plane3 &plane,
2230	BoundedRayContainer &rays,
2231	BoundedRayContainer &frontRays,
2232	BoundedRayContainer &backRays)
2233	{
2234	int splits = 0;
2235
2236	while (!rays.empty())
2237	{
2238	BoundedRay *bRay = rays.back();
2239	Ray *ray = bRay->mRay;
2240	float minT = bRay->mMinT;
2241	float maxT = bRay->mMaxT;
2242
2243	rays.pop_back();
2244
2245	Vector3 entP, extP;
2246
2247	const int cf =
2248	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2249
2250	// set id to ray classification
2251	ray->SetId(cf);
2252
2253	switch (cf)
2254	{
2255	case Ray::COINCIDENT: // TODO: should really discard ray?
2256	frontRays.push_back(bRay);
2257	//DEL_PTR(bRay);
2258	break;
2259	case Ray::BACK:
2260	backRays.push_back(bRay);
2261	break;
2262	case Ray::FRONT:
2263	frontRays.push_back(bRay);
2264	break;
2265	case Ray::FRONT_BACK:
2266	{
2267	// find intersection of ray segment with plane
2268	const float t = plane.FindT(ray->GetLoc(), extP);
2269
2270	const float newT = t * maxT;
2271
2272	frontRays.push_back(new BoundedRay(ray, minT, newT));
2273	backRays.push_back(new BoundedRay(ray, newT, maxT));
2274
2275	DEL_PTR(bRay);
2276	}
2277	break;
2278	case Ray::BACK_FRONT:
2279	{
2280	// find intersection of ray segment with plane
2281	const float t = plane.FindT(ray->GetLoc(), extP);
2282	const float newT = t * bRay->mMaxT;
2283
2284	backRays.push_back(new BoundedRay(ray, minT, newT));
2285	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2286
2287	DEL_PTR(bRay);
2288
2289	++ splits;
2290	}
2291	break;
2292	default:
2293	Debug << "Should not come here 4" << endl;
2294	break;
2295	}
2296	}
2297
2298	return splits;
2299	}
2300
2301	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2302	{
2303	BspNode *lastNode;
2304	do
2305	{
2306	lastNode = n;
2307
2308	// want to get planes defining geometry of this node => don't take
2309	// split plane of node itself
2310	n = n->GetParent();
2311
2312	if (n)
2313	{
2314	BspInterior interior = dynamic_cast<BspInterior >(n);
2315	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2316
2317	if (interior->GetFront() != lastNode)
2318	halfSpace.ReverseOrientation();
2319
2320	halfSpaces.push_back(halfSpace);
2321	}
2322	}
2323	while (n);
2324	}
2325
2326
2327
2328	void BspTree::ConstructGeometry(ViewCell *vc,
2329	BspNodeGeometry &vcGeom) const
2330	{
2331	ViewCellContainer leaves;
2332	mViewCellsTree->CollectLeaves(vc, leaves);
2333
2334	ViewCellContainer::const_iterator it, it_end = leaves.end();
2335
2336	for (it = leaves.begin(); it != it_end; ++ it)
2337	{
2338	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2339	ConstructGeometry(l, vcGeom);
2340	}
2341	}
2342
2343
2344	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2345	{
2346	mViewCellsManager = vcm;
2347	}
2348
2349
2350	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2351	{
2352	vector<Plane3> halfSpaces;
2353	ExtractHalfSpaces(n, halfSpaces);
2354
2355	PolygonContainer candidates;
2356
2357	// bounded planes are added to the polygons (reverse polygons
2358	// as they have to be outfacing
2359	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2360	{
2361	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2362
2363	if (p->Valid(mEpsilon))
2364	{
2365	candidates.push_back(p->CreateReversePolygon());
2366	DEL_PTR(p);
2367	}
2368	}
2369
2370	// add faces of bounding box (also could be faces of the cell)
2371	for (int i = 0; i < 6; ++ i)
2372	{
2373	VertexContainer vertices;
2374
2375	for (int j = 0; j < 4; ++ j)
2376	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2377
2378	candidates.push_back(new Polygon3(vertices));
2379	}
2380
2381	for (int i = 0; i < (int)candidates.size(); ++ i)
2382	{
2383	// polygon is split by all other planes
2384	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2385	{
2386	if (i == j) // polygon and plane are coincident
2387	continue;
2388
2389	VertexContainer splitPts;
2390	Polygon3 frontPoly, backPoly;
2391
2392	const int cf = candidates[i]->
2393	ClassifyPlane(halfSpaces[j], mEpsilon);
2394
2395	switch (cf)
2396	{
2397	case Polygon3::SPLIT:
2398	frontPoly = new Polygon3();
2399	backPoly = new Polygon3();
2400
2401	candidates[i]->Split(halfSpaces[j],
2402	*frontPoly,
2403	*backPoly,
2404	mEpsilon);
2405
2406	DEL_PTR(candidates[i]);
2407
2408	if (frontPoly->Valid(mEpsilon))
2409	candidates[i] = frontPoly;
2410	else
2411	DEL_PTR(frontPoly);
2412
2413	DEL_PTR(backPoly);
2414	break;
2415	case Polygon3::BACK_SIDE:
2416	DEL_PTR(candidates[i]);
2417	break;
2418	// just take polygon as it is
2419	case Polygon3::FRONT_SIDE:
2420	case Polygon3::COINCIDENT:
2421	default:
2422	break;
2423	}
2424	}
2425
2426	if (candidates[i])
2427	geom.mPolys.push_back(candidates[i]);
2428	}
2429	}
2430
2431
2432	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2433
2434
2435	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2436	const bool onlyUnmailed) const
2437	{
2438	stack<bspNodePair> nodeStack;
2439
2440	BspNodeGeometry nodeGeom;
2441	ConstructGeometry(n, nodeGeom);
2442
2443	// split planes from the root to this node
2444	// needed to verify that we found neighbor leaf
2445	// TODO: really needed?
2446	vector<Plane3> halfSpaces;
2447	ExtractHalfSpaces(n, halfSpaces);
2448
2449
2450	BspNodeGeometry *rgeom = new BspNodeGeometry();
2451	ConstructGeometry(mRoot, *rgeom);
2452
2453	nodeStack.push(bspNodePair(mRoot, rgeom));
2454
2455	while (!nodeStack.empty())
2456	{
2457	BspNode *node = nodeStack.top().first;
2458	BspNodeGeometry *geom = nodeStack.top().second;
2459
2460	nodeStack.pop();
2461
2462	if (node->IsLeaf())
2463	{
2464	// test if this leaf is in valid view space
2465	if (node->TreeValid() &&
2466	(node != n) &&
2467	(!onlyUnmailed \|\| !node->Mailed()))
2468	{
2469	bool isAdjacent = true;
2470
2471	if (1)
2472	{
2473	// test all planes of current node if still adjacent
2474	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2475	{
2476	const int cf =
2477	Polygon3::ClassifyPlane(geom->mPolys,
2478	halfSpaces[i],
2479	mEpsilon);
2480
2481	if (cf == Polygon3::BACK_SIDE)
2482	{
2483	isAdjacent = false;
2484	}
2485	}
2486	}
2487	else
2488	{
2489	// TODO: why is this wrong??
2490	// test all planes of current node if still adjacent
2491	for (int i = 0; (i < (int)nodeGeom.mPolys.size()) && isAdjacent; ++ i)
2492	{
2493	Polygon3 *poly = nodeGeom.mPolys[i];
2494
2495	const int cf =
2496	Polygon3::ClassifyPlane(geom->mPolys,
2497	poly->GetSupportingPlane(),
2498	mEpsilon);
2499
2500	if (cf == Polygon3::BACK_SIDE)
2501	{
2502	isAdjacent = false;
2503	}
2504	}
2505	}
2506	// neighbor was found
2507	if (isAdjacent)
2508	{
2509	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2510	}
2511	}
2512	}
2513	else
2514	{
2515	BspInterior interior = dynamic_cast<BspInterior >(node);
2516
2517	const int cf = Polygon3::ClassifyPlane(nodeGeom.mPolys,
2518	interior->GetPlane(),
2519	mEpsilon);
2520
2521	BspNode *front = interior->GetFront();
2522	BspNode *back = interior->GetBack();
2523
2524	BspNodeGeometry *fGeom = new BspNodeGeometry();
2525	BspNodeGeometry *bGeom = new BspNodeGeometry();
2526
2527	geom->SplitGeometry(*fGeom,
2528	*bGeom,
2529	interior->GetPlane(),
2530	mBox,
2531	mEpsilon);
2532
2533	if (cf == Polygon3::FRONT_SIDE)
2534	{
2535	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2536	DEL_PTR(bGeom);
2537	}
2538	else
2539	{
2540	if (cf == Polygon3::BACK_SIDE)
2541	{
2542	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2543	DEL_PTR(fGeom);
2544	}
2545	else
2546	{ // random decision
2547	nodeStack.push(bspNodePair(front, fGeom));
2548	nodeStack.push(bspNodePair(back, bGeom));
2549	}
2550	}
2551	}
2552
2553	DEL_PTR(geom);
2554	}
2555
2556	return (int)neighbors.size();
2557	}
2558
2559
2560	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2561	{
2562	stack<BspNode *> nodeStack;
2563	nodeStack.push(mRoot);
2564
2565	int mask = rand();
2566
2567	while (!nodeStack.empty())
2568	{
2569	BspNode *node = nodeStack.top();
2570	nodeStack.pop();
2571
2572	if (node->IsLeaf())
2573	{
2574	return dynamic_cast<BspLeaf *>(node);
2575	}
2576	else
2577	{
2578	BspInterior interior = dynamic_cast<BspInterior >(node);
2579	BspNode *next;
2580
2581	BspNodeGeometry geom;
2582	// todo: not very efficient: constructs full cell everytime
2583	ConstructGeometry(interior, geom);
2584
2585	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2586	halfspace,
2587	mEpsilon);
2588
2589	if (cf == Polygon3::BACK_SIDE)
2590	next = interior->GetFront();
2591	else
2592	if (cf == Polygon3::FRONT_SIDE)
2593	next = interior->GetFront();
2594	else
2595	{
2596	// random decision
2597	if (mask & 1)
2598	next = interior->GetBack();
2599	else
2600	next = interior->GetFront();
2601	mask = mask >> 1;
2602	}
2603
2604	nodeStack.push(next);
2605	}
2606	}
2607
2608	return NULL;
2609	}
2610
2611
2612	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2613	{
2614	stack<BspNode *> nodeStack;
2615
2616	nodeStack.push(mRoot);
2617
2618	int mask = rand();
2619
2620	while (!nodeStack.empty())
2621	{
2622	BspNode *node = nodeStack.top();
2623	nodeStack.pop();
2624
2625	if (node->IsLeaf())
2626	{
2627	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2628	return dynamic_cast<BspLeaf *>(node);
2629	}
2630	else
2631	{
2632	BspInterior interior = dynamic_cast<BspInterior >(node);
2633
2634	// random decision
2635	if (mask & 1)
2636	nodeStack.push(interior->GetBack());
2637	else
2638	nodeStack.push(interior->GetFront());
2639
2640	mask = mask >> 1;
2641	}
2642	}
2643
2644	return NULL;
2645	}
2646
2647
2648	void BspTree::AddToPvs(BspLeaf *leaf,
2649	const BoundedRayContainer &rays,
2650	int &sampleContributions,
2651	int &contributingSamples)
2652	{
2653	sampleContributions = 0;
2654	contributingSamples = 0;
2655
2656	BoundedRayContainer::const_iterator it, it_end = rays.end();
2657
2658	ViewCell *vc = leaf->GetViewCell();
2659
2660	// add contributions from samples to the PVS
2661	for (it = rays.begin(); it != it_end; ++ it)
2662	{
2663	int contribution = 0;
2664	Ray ray = (it)->mRay;
2665	float relContribution;
2666	if (!ray->intersections.empty())
2667	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2668	1.0f,
2669	relContribution);
2670
2671	if (ray->sourceObject.mObject)
2672	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2673	1.0f,
2674	relContribution);
2675
2676	if (contribution)
2677	{
2678	sampleContributions += contribution;
2679	++ contributingSamples;
2680	}
2681
2682	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2683	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2684	}
2685	}
2686
2687
2688	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2689	{
2690	int pvsSize = 0;
2691
2692	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2693
2694	Intersectable::NewMail();
2695
2696	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2697	{
2698	Ray ray = (rit)->mRay;
2699
2700	if (!ray->intersections.empty())
2701	{
2702	if (!ray->intersections[0].mObject->Mailed())
2703	{
2704	ray->intersections[0].mObject->Mail();
2705	++ pvsSize;
2706	}
2707	}
2708	if (ray->sourceObject.mObject)
2709	{
2710	if (!ray->sourceObject.mObject->Mailed())
2711	{
2712	ray->sourceObject.mObject->Mail();
2713	++ pvsSize;
2714	}
2715	}
2716	}
2717
2718	return pvsSize;
2719	}
2720
2721
2722	float BspTree::GetEpsilon() const
2723	{
2724	return mEpsilon;
2725	}
2726
2727
2728	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2729	vector<MergeCandidate> &candidates)
2730	{
2731	BspLeaf::NewMail();
2732
2733	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2734
2735	int numCandidates = 0;
2736
2737	// find merge candidates and push them into queue
2738	for (it = leaves.begin(); it != it_end; ++ it)
2739	{
2740	BspLeaf leaf = it;
2741
2742	// the same leaves must not be part of two merge candidates
2743	leaf->Mail();
2744	vector<BspLeaf *> neighbors;
2745	FindNeighbors(leaf, neighbors, true);
2746
2747	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2748
2749	// TODO: test if at least one ray goes from one leaf to the other
2750	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2751	{
2752	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2753	{
2754	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2755	candidates.push_back(mc);
2756
2757	++ numCandidates;
2758	if ((numCandidates % 1000) == 0)
2759	{
2760	cout << "collected " << numCandidates << " merge candidates" << endl;
2761	}
2762	}
2763	}
2764	}
2765
2766	Debug << "merge queue: " << (int)candidates.size() << endl;
2767	Debug << "leaves in queue: " << numCandidates << endl;
2768
2769
2770	return (int)leaves.size();
2771	}
2772
2773
2774	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2775	vector<MergeCandidate> &candidates)
2776	{
2777	ViewCell::NewMail();
2778	long startTime = GetTime();
2779
2780	map<BspLeaf , vector<BspLeaf> > neighborMap;
2781	ViewCellContainer::const_iterator iit;
2782
2783	int numLeaves = 0;
2784
2785	BspLeaf::NewMail();
2786
2787	for (int i = 0; i < (int)rays.size(); ++ i)
2788	{
2789	VssRay *ray = rays[i];
2790
2791	// traverse leaves stored in the rays and compare and
2792	// merge consecutive leaves (i.e., the neighbors in the tree)
2793	if (ray->mViewCells.size() < 2)
2794	continue;
2795
2796	iit = ray->mViewCells.begin();
2797	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2798	BspLeaf *leaf = bspVc->mLeaf;
2799
2800	// traverse intersections
2801	// consecutive leaves are neighbors => add them to queue
2802	for (; iit != ray->mViewCells.end(); ++ iit)
2803	{
2804	// next pair
2805	BspLeaf *prevLeaf = leaf;
2806	bspVc = dynamic_cast<BspViewCell >(iit);
2807	leaf = bspVc->mLeaf;
2808
2809	// view space not valid or same view cell
2810	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2811	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2812	continue;
2813
2814	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2815
2816	bool found = false;
2817
2818	// both leaves inserted in queue already =>
2819	// look if double pair already exists
2820	if (leaf->Mailed() && prevLeaf->Mailed())
2821	{
2822	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2823
2824	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2825	if (*it == prevLeaf)
2826	found = true; // already in queue
2827	}
2828
2829	if (!found)
2830	{
2831	// this pair is not in map yet
2832	// => insert into the neighbor map and the queue
2833	neighbors.push_back(prevLeaf);
2834	neighborMap[prevLeaf].push_back(leaf);
2835
2836	leaf->Mail();
2837	prevLeaf->Mail();
2838
2839	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2840
2841	candidates.push_back(mc);
2842
2843	if (((int)candidates.size() % 1000) == 0)
2844	{
2845	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2846	}
2847	}
2848	}
2849	}
2850
2851	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2852	Debug << "merge queue: " << (int)candidates.size() << endl;
2853	Debug << "leaves in queue: " << numLeaves << endl;
2854
2855
2856	//-- collect the leaves which haven't been found by ray casting
2857	#if 0
2858	cout << "finding additional merge candidates using geometry" << endl;
2859	vector<BspLeaf *> leaves;
2860	CollectLeaves(leaves, true);
2861	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2862	CollectMergeCandidates(leaves, candidates);
2863	#endif
2864
2865	return numLeaves;
2866	}
2867
2868
2869
2870
2871	/***************************************************************/
2872	/* BspNodeGeometry Implementation */
2873	/***************************************************************/
2874
2875
2876	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2877	{
2878	mPolys.reserve(rhs.mPolys.size());
2879
2880	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2881	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2882	{
2883	Polygon3 poly = it;
2884	mPolys.push_back(new Polygon3(*poly));
2885	}
2886	}
2887
2888
2889	BspNodeGeometry::~BspNodeGeometry()
2890	{
2891	CLEAR_CONTAINER(mPolys);
2892	}
2893
2894
2895	float BspNodeGeometry::GetArea() const
2896	{
2897	return Polygon3::GetArea(mPolys);
2898	}
2899
2900
2901	float BspNodeGeometry::GetVolume() const
2902	{
2903	//-- compute volume using tetrahedralization of the geometry
2904	// and adding the volume of the single tetrahedrons
2905	float volume = 0;
2906	const float f = 1.0f / 6.0f;
2907
2908	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2909
2910	// note: can take arbitrary point, e.g., the origin. However,
2911	// we rather take the center of mass to prevents precision errors
2912	const Vector3 center = CenterOfMass();
2913
2914	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2915	{
2916	Polygon3 poly = pit;
2917	const Vector3 v0 = poly->mVertices[0] - center;
2918
2919	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2920	{
2921	const Vector3 v1 = poly->mVertices[i] - center;
2922	const Vector3 v2 = poly->mVertices[i + 1] - center;
2923
2924	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2925	}
2926	}
2927
2928	return volume;
2929	}
2930
2931
2932	Vector3 BspNodeGeometry::CenterOfMass() const
2933	{
2934	int n = 0;
2935
2936	Vector3 center(0,0,0);
2937
2938	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2939
2940	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2941	{
2942	Polygon3 poly = pit;
2943
2944	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2945
2946	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2947	{
2948	center += *vit;
2949	++ n;
2950	}
2951	}
2952
2953	return center / (float)n;
2954	}
2955
2956
2957	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2958	{
2959	PolygonContainer::const_iterator it, it_end = mPolys.end();
2960
2961	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2962	{
2963	(*it)->AddToMesh(mesh);
2964	}
2965	}
2966
2967
2968	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2969	BspNodeGeometry &back,
2970	const Plane3 &splitPlane,
2971	const AxisAlignedBox3 &box,
2972	const float epsilon) const
2973	{
2974	// get cross section of new polygon
2975	Polygon3 *planePoly = box.CrossSection(splitPlane);
2976
2977	// split polygon with all other polygons
2978	planePoly = SplitPolygon(planePoly, epsilon);
2979
2980	//-- new polygon splits all other polygons
2981	for (int i = 0; i < (int)mPolys.size(); ++ i)
2982	{
2983	/// don't use epsilon here to get exact split planes
2984	const int cf =
2985	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2986
2987	switch (cf)
2988	{
2989	case Polygon3::SPLIT:
2990	{
2991	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2992
2993	Polygon3 *frontPoly = new Polygon3();
2994	Polygon3 *backPoly = new Polygon3();
2995
2996	poly->Split(splitPlane,
2997	*frontPoly,
2998	*backPoly,
2999	epsilon);
3000
3001	DEL_PTR(poly);
3002
3003	if (frontPoly->Valid(epsilon))
3004	front.mPolys.push_back(frontPoly);
3005	else
3006	DEL_PTR(frontPoly);
3007
3008	if (backPoly->Valid(epsilon))
3009	back.mPolys.push_back(backPoly);
3010	else
3011	DEL_PTR(backPoly);
3012	}
3013
3014	break;
3015	case Polygon3::BACK_SIDE:
3016	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3017	break;
3018	case Polygon3::FRONT_SIDE:
3019	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3020	break;
3021	case Polygon3::COINCIDENT:
3022	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
3023	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3024	break;
3025	default:
3026	break;
3027	}
3028	}
3029
3030	//-- finally add the new polygon to the child node geometries
3031	if (planePoly)
3032	{
3033	// add polygon with normal pointing into positive half space to back cell
3034	back.mPolys.push_back(planePoly);
3035	// add polygon with reverse orientation to front cell
3036	front.mPolys.push_back(planePoly->CreateReversePolygon());
3037	}
3038	}
3039
3040
3041	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3042	const float epsilon) const
3043	{
3044	if (!planePoly->Valid(epsilon))
3045	DEL_PTR(planePoly);
3046
3047	// polygon is split by all other planes
3048	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3049	{
3050	Plane3 plane = mPolys[i]->GetSupportingPlane();
3051
3052	/// don't use epsilon here to get exact split planes
3053	const int cf =
3054	planePoly->ClassifyPlane(plane, Limits::Small);
3055
3056	// split new polygon with all previous planes
3057	switch (cf)
3058	{
3059	case Polygon3::SPLIT:
3060	{
3061	Polygon3 *frontPoly = new Polygon3();
3062	Polygon3 *backPoly = new Polygon3();
3063
3064	planePoly->Split(plane,
3065	*frontPoly,
3066	*backPoly,
3067	epsilon);
3068
3069	// don't need anymore
3070	DEL_PTR(planePoly);
3071	DEL_PTR(frontPoly);
3072
3073	// back polygon is belonging to geometry
3074	if (backPoly->Valid(epsilon))
3075	planePoly = backPoly;
3076	else
3077	DEL_PTR(backPoly);
3078	}
3079	break;
3080	case Polygon3::FRONT_SIDE:
3081	DEL_PTR(planePoly);
3082	break;
3083	// polygon is taken as it is
3084	case Polygon3::BACK_SIDE:
3085	case Polygon3::COINCIDENT:
3086	default:
3087	break;
3088	}
3089	}
3090
3091	return planePoly;
3092	}
3093
3094
3095	ViewCell *
3096	BspTree::GetViewCell(const Vector3 &point)
3097	{
3098	if (mRoot == NULL)
3099	return NULL;
3100
3101
3102	stack<BspNode *> nodeStack;
3103	nodeStack.push(mRoot);
3104
3105	ViewCell *viewcell = NULL;
3106
3107	while (!nodeStack.empty()) {
3108	BspNode *node = nodeStack.top();
3109	nodeStack.pop();
3110
3111	if (node->IsLeaf()) {
3112	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3113	break;
3114	} else {
3115
3116	BspInterior interior = dynamic_cast<BspInterior >(node);
3117
3118	// random decision
3119	if (interior->GetPlane().Side(point) < 0)
3120	nodeStack.push(interior->GetBack());
3121	else
3122	nodeStack.push(interior->GetFront());
3123	}
3124	}
3125
3126	return viewcell;
3127	}
3128
3129
3130	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
3131	{
3132	Polygon3::IncludeInBox(mPolys, box);
3133	}
3134
3135
3136	bool BspTree::Export(ofstream &stream)
3137	{
3138	ExportNode(mRoot, stream);
3139
3140	return true;
3141	}
3142
3143
3144	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3145	{
3146	if (node->IsLeaf())
3147	{
3148	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3149
3150	int id = -1;
3151	if (leaf->GetViewCell() != mOutOfBoundsCell)
3152	id = leaf->GetViewCell()->GetId();
3153
3154	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3155	}
3156	else
3157	{
3158	BspInterior interior = dynamic_cast<BspInterior >(node);
3159
3160	Plane3 plane = interior->GetPlane();
3161	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3162	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3163	<< plane.mD << "\">" << endl;
3164
3165	ExportNode(interior->GetBack(), stream);
3166	ExportNode(interior->GetFront(), stream);
3167
3168	stream << "</Interior>" << endl;
3169	}
3170	}

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