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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 710

Revision 710, 80.3 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	/****************************************************************/
164	/* class BspLeaf implementation */
165	/****************************************************************/
166
167
168	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
169	{
170	}
171
172
173	BspLeaf::~BspLeaf()
174	{
175	DEL_PTR(mPvs);
176	}
177
178
179	BspLeaf::BspLeaf(ViewCell *viewCell):
180	mViewCell(viewCell)
181	{
182	}
183
184
185	BspLeaf::BspLeaf(BspInterior *parent):
186	BspNode(parent), mViewCell(NULL), mPvs(NULL)
187	{}
188
189
190
191	BspLeaf::BspLeaf(BspInterior parent, ViewCell viewCell):
192	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
193	{
194	}
195
196	ViewCell *BspLeaf::GetViewCell() const
197	{
198	return mViewCell;
199	}
200
201	void BspLeaf::SetViewCell(ViewCell *viewCell)
202	{
203	mViewCell = viewCell;
204	}
205
206
207	bool BspLeaf::IsLeaf() const
208	{
209	return true;
210	}
211
212
213	/*********************************************************************/
214	/* class BspTree implementation */
215	/*********************************************************************/
216
217	BspTree::BspTree():
218	mRoot(NULL),
219	mUseAreaForPvs(false),
220	mGenerateViewCells(true),
221	mTimeStamp(1)
222	{
223	Randomize(); // initialise random generator for heuristics
224
225	mOutOfBoundsCell = GetOrCreateOutOfBoundsCell();
226
227	//-- termination criteria for autopartition
228	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
229	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
230	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
231	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
232	environment->GetFloatValue("BspTree.Termination.minProbability", mTermMinProbability);
233	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
234	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
235
236	//-- factors for bsp tree split plane heuristics
237	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
238	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
239	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
240	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
241	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
242	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
243	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
244	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
245	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
246	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
247
248	//-- termination criteria for axis aligned split
249	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
250	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
251	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
252	mTermMinPolysForAxisAligned);
253	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
254	mTermMinRaysForAxisAligned);
255	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
256	mTermMinObjectsForAxisAligned);
257	//-- partition criteria
258	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
259	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
260	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
261	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
262	environment->GetIntValue("BspTree.maxTests", mMaxTests);
263	environment->GetIntValue("BspTree.Termination.maxViewCells", mMaxViewCells);
264
265	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
266
267	char subdivisionStatsLog[100];
268	environment->GetStringValue("BspTree.subdivisionStats", subdivisionStatsLog);
269	mSubdivisionStats.open(subdivisionStatsLog);
270
271	Debug << "BSP max depth: " << mTermMaxDepth << endl;
272	Debug << "BSP min PVS: " << mTermMinPvs << endl;
273	Debug << "BSP min probability: " << mTermMinProbability << endl;
274	Debug << "BSP max polys: " << mTermMinPolys << endl;
275	Debug << "BSP max rays: " << mTermMinRays << endl;
276	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
277	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
278
279	Debug << "Split plane strategy: ";
280	if (mSplitPlaneStrategy & RANDOM_POLYGON)
281	Debug << "random polygon ";
282	if (mSplitPlaneStrategy & AXIS_ALIGNED)
283	Debug << "axis aligned ";
284	if (mSplitPlaneStrategy & LEAST_SPLITS)
285	Debug << "least splits ";
286	if (mSplitPlaneStrategy & BALANCED_POLYS)
287	Debug << "balanced polygons ";
288	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
289	Debug << "balanced view cells ";
290	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
291	Debug << "largest polygon area ";
292	if (mSplitPlaneStrategy & VERTICAL_AXIS)
293	Debug << "vertical axis ";
294	if (mSplitPlaneStrategy & BLOCKED_RAYS)
295	Debug << "blocked rays ";
296	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
297	Debug << "least ray splits ";
298	if (mSplitPlaneStrategy & BALANCED_RAYS)
299	Debug << "balanced rays ";
300	if (mSplitPlaneStrategy & PVS)
301	Debug << "pvs";
302
303	Debug << endl;
304	}
305
306
307	const BspTreeStatistics &BspTree::GetStatistics() const
308	{
309	return mStat;
310	}
311
312
313	int BspTree::SplitPolygons(const Plane3 &plane,
314	PolygonContainer &polys,
315	PolygonContainer &frontPolys,
316	PolygonContainer &backPolys,
317	PolygonContainer &coincident) const
318	{
319	int splits = 0;
320
321	#ifdef _Debug
322	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
323	#endif
324
325	PolygonContainer::const_iterator it, it_end = polys.end();
326
327	for (it = polys.begin(); it != polys.end(); ++ it)
328	{
329	Polygon3 poly = it;
330
331	//-- classify polygon
332	const int cf = poly->ClassifyPlane(plane, mEpsilon);
333
334	switch (cf)
335	{
336	case Polygon3::COINCIDENT:
337	coincident.push_back(poly);
338	break;
339	case Polygon3::FRONT_SIDE:
340	frontPolys.push_back(poly);
341	break;
342	case Polygon3::BACK_SIDE:
343	backPolys.push_back(poly);
344	break;
345	case Polygon3::SPLIT:
346	{
347	Polygon3 *front_piece = new Polygon3(poly->mParent);
348	Polygon3 *back_piece = new Polygon3(poly->mParent);
349
350	//-- split polygon into front and back part
351	poly->Split(plane,
352	*front_piece,
353	*back_piece,
354	mEpsilon);
355
356	++ splits; // increase number of splits
357
358	//-- inherit rays from parent polygon for blocked ray criterium
359	poly->InheritRays(front_piece, back_piece);
360
361	// check if polygons still valid
362	if (front_piece->Valid(mEpsilon))
363	frontPolys.push_back(front_piece);
364	else
365	DEL_PTR(front_piece);
366
367	if (back_piece->Valid(mEpsilon))
368	backPolys.push_back(back_piece);
369	else
370	DEL_PTR(back_piece);
371
372	#ifdef _DEBUG
373	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
374	#endif
375	DEL_PTR(poly);
376	}
377	break;
378	default:
379	Debug << "SHOULD NEVER COME HERE\n";
380	break;
381	}
382	}
383
384	return splits;
385	}
386
387
388	void BspTreeStatistics::Print(ostream &app) const
389	{
390	app << "===== BspTree statistics ===============\n";
391
392	app << setprecision(4);
393
394	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
395
396	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
397
398	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
399
400	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
401
402	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
403
404	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
405
406	app << "#N_SPLITS ( Number of splits in axes x y z)\n";
407
408	for (int i = 0; i < 3; ++ i)
409	app << splits[i] << " ";
410	app << endl;
411
412	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
413	<< maxDepthNodes * 100 / (double)Leaves() << endl;
414
415	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
416	<< minPvsNodes * 100 / (double)Leaves() << endl;
417
418	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
419	<< minRaysNodes * 100 / (double)Leaves() << endl;
420
421	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
422	<< maxCostNodes * 100 / (double)Leaves() << endl;
423
424	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
425	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
426
427	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
428	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
429
430	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
431
432	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
433
434	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
435
436	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
437
438	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
439
440	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
441	//app << "#N_PVS: " << pvs << endl;
442
443	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
444	(polys + polySplits) / (double)polys << endl;
445
446	app << "===== END OF BspTree statistics ==========\n";
447	}
448
449
450	BspTree::~BspTree()
451	{
452	DEL_PTR(mRoot);
453
454	// TODO must be deleted if used!!
455	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
456	}
457
458	BspViewCell *BspTree::GetOutOfBoundsCell()
459	{
460	return mOutOfBoundsCell;
461	}
462
463
464	BspNode *BspTree::GetRoot() const
465	{
466	return mRoot;
467	}
468
469	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
470	{
471	if (!mOutOfBoundsCell)
472	{
473	mOutOfBoundsCell = new BspViewCell();
474	mOutOfBoundsCell->SetId(-1);
475	mOutOfBoundsCell->SetValid(false);
476	}
477
478	return mOutOfBoundsCell;
479	}
480
481
482	void BspTree::InsertViewCell(ViewCell *viewCell)
483	{
484	PolygonContainer *polys = new PolygonContainer();
485
486	// don't generate new view cell, insert this one
487	mGenerateViewCells = false;
488	// extract polygons that guide the split process
489	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
490	mBox.Include(viewCell->GetBox()); // add to BSP aabb
491
492	InsertPolygons(polys);
493	}
494
495
496	void BspTree::InsertPolygons(PolygonContainer *polys)
497	{
498	BspTraversalStack tStack;
499
500	// traverse existing tree or create new tree
501	if (!mRoot)
502	mRoot = new BspLeaf();
503
504	tStack.push(BspTraversalData(mRoot,
505	polys,
506	0,
507	mOutOfBoundsCell,
508	new BoundedRayContainer(),
509	0,
510	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
511	new BspNodeGeometry()));
512
513	while (!tStack.empty())
514	{
515	// filter polygons donw the tree
516	BspTraversalData tData = tStack.top();
517	tStack.pop();
518
519	if (!tData.mNode->IsLeaf())
520	{
521	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
522
523	//-- filter view cell polygons down the tree until a leaf is reached
524	if (!tData.mPolygons->empty())
525	{
526	PolygonContainer *frontPolys = new PolygonContainer();
527	PolygonContainer *backPolys = new PolygonContainer();
528	PolygonContainer coincident;
529
530	int splits = 0;
531
532	// split viewcell polygons with respect to split plane
533	splits += SplitPolygons(interior->GetPlane(),
534	*tData.mPolygons,
535	*frontPolys,
536	*backPolys,
537	coincident);
538
539	// extract view cells associated with the split polygons
540	ViewCell *frontViewCell = GetOrCreateOutOfBoundsCell();
541	ViewCell *backViewCell = GetOrCreateOutOfBoundsCell();
542
543	BspTraversalData frontData(interior->GetFront(),
544	frontPolys,
545	tData.mDepth + 1,
546	mOutOfBoundsCell,
547	tData.mRays,
548	tData.mPvs,
549	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
550	new BspNodeGeometry());
551
552	BspTraversalData backData(interior->GetBack(),
553	backPolys,
554	tData.mDepth + 1,
555	mOutOfBoundsCell,
556	tData.mRays,
557	tData.mPvs,
558	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
559	new BspNodeGeometry());
560
561	if (!mGenerateViewCells)
562	{
563	ExtractViewCells(frontData,
564	backData,
565	coincident,
566	interior->mPlane);
567	}
568
569	// don't need coincident polygons anymore
570	CLEAR_CONTAINER(coincident);
571
572	mStat.polySplits += splits;
573
574	// push the children on the stack
575	tStack.push(frontData);
576	tStack.push(backData);
577	}
578
579	// cleanup
580	DEL_PTR(tData.mPolygons);
581	DEL_PTR(tData.mRays);
582	}
583	else
584	{
585	// reached leaf => subdivide current viewcell
586	BspNode *subRoot = Subdivide(tStack, tData);
587	}
588	}
589	}
590
591
592	int BspTree::AddMeshToPolygons(Mesh *mesh,
593	PolygonContainer &polys,
594	MeshInstance *parent)
595	{
596	FaceContainer::const_iterator fi, fi_end = mesh->mFaces.end();
597
598	// copy the face data to polygons
599	for (fi = mesh->mFaces.begin(); fi != fi_end; ++ fi)
600	{
601	Polygon3 poly = new Polygon3((fi), mesh);
602
603	if (poly->Valid(mEpsilon))
604	{
605	poly->mParent = parent; // set parent intersectable
606	polys.push_back(poly);
607	}
608	else
609	DEL_PTR(poly);
610	}
611	return (int)mesh->mFaces.size();
612	}
613
614
615	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
616	PolygonContainer &polys,
617	int maxObjects)
618	{
619	int limit = (maxObjects > 0) ?
620	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
621
622	int polysSize = 0;
623
624	for (int i = 0; i < limit; ++ i)
625	{
626	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
627	{
628	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
629	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
630	}
631	}
632
633	return polysSize;
634	}
635
636
637	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
638	PolygonContainer &polys,
639	int maxObjects,
640	bool addToBbox)
641	{
642	int limit = (maxObjects > 0) ?
643	Min((int)objects.size(), maxObjects) : (int)objects.size();
644
645	for (int i = 0; i < limit; ++i)
646	{
647	Intersectable object = objects[i];//it;
648	Mesh *mesh = NULL;
649
650	switch (object->Type()) // extract the meshes
651	{
652	case Intersectable::MESH_INSTANCE:
653	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
654	break;
655	case Intersectable::VIEW_CELL:
656	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
657	break;
658	// TODO: handle transformed mesh instances
659	default:
660	Debug << "intersectable type not supported" << endl;
661	break;
662	}
663
664	if (mesh) // copy the mesh data to polygons
665	{
666	if (addToBbox)
667	{
668	mBox.Include(object->GetBox()); // add to BSP tree aabb
669	}
670
671	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
672	}
673	}
674
675	return (int)polys.size();
676	}
677
678
679	void BspTree::Construct(const ViewCellContainer &viewCells)
680	{
681	mStat.nodes = 1;
682	mBox.Initialize(); // initialise bsp tree bounding box
683
684	// copy view cell meshes into one big polygon soup
685	PolygonContainer *polys = new PolygonContainer();
686	mStat.polys = AddToPolygonSoup(viewCells, *polys);
687
688	// view cells are given
689	mGenerateViewCells = false;
690	// construct tree from the view cell polygons
691	Construct(polys, new BoundedRayContainer());
692	}
693
694
695	void BspTree::Construct(const ObjectContainer &objects)
696	{
697	mStat.nodes = 1;
698	mBox.Initialize(); // initialise bsp tree bounding box
699
700	PolygonContainer *polys = new PolygonContainer();
701
702	mGenerateViewCells = true;
703	// copy mesh instance polygons into one big polygon soup
704	mStat.polys = AddToPolygonSoup(objects, *polys);
705
706	// construct tree from polygon soup
707	Construct(polys, new BoundedRayContainer());
708	}
709
710
711	void BspTree::PreprocessPolygons(PolygonContainer &polys)
712	{
713	// preprocess: throw out polygons coincident to the view space box (not needed)
714	PolygonContainer boxPolys;
715	mBox.ExtractPolys(boxPolys);
716	vector<Plane3> boxPlanes;
717
718	PolygonContainer::iterator pit, pit_end = boxPolys.end();
719
720	// extract planes of box
721	// TODO: can be done more elegantly than first extracting polygons
722	// and take their planes
723	for (pit = boxPolys.begin(); pit != pit_end; ++ pit)
724	{
725	boxPlanes.push_back((*pit)->GetSupportingPlane());
726	}
727
728	pit_end = polys.end();
729
730	for (pit = polys.begin(); pit != pit_end; ++ pit)
731	{
732	vector<Plane3>::const_iterator bit, bit_end = boxPlanes.end();
733
734	for (bit = boxPlanes.begin(); (bit != bit_end) && (*pit); ++ bit)
735	{
736	const int cf = (pit)->ClassifyPlane(bit, mEpsilon);
737
738	if (cf == Polygon3::COINCIDENT)
739	{
740	DEL_PTR(*pit);
741	//Debug << "coincident!!" << endl;
742	}
743	}
744	}
745
746	// remove deleted entries
747	for (int i = 0; i < (int)polys.size(); ++ i)
748	{
749	while (!polys[i] && (i < (int)polys.size()))
750	{
751	swap(polys[i], polys.back());
752	polys.pop_back();
753	}
754	}
755	}
756
757
758
759	void BspTree::Construct(const RayContainer &sampleRays,
760	AxisAlignedBox3 *forcedBoundingBox)
761	{
762	mStat.nodes = 1;
763	mBox.Initialize(); // initialise BSP tree bounding box
764
765	if (forcedBoundingBox)
766	mBox = *forcedBoundingBox;
767
768	PolygonContainer *polys = new PolygonContainer();
769	BoundedRayContainer *rays = new BoundedRayContainer();
770
771	RayContainer::const_iterator rit, rit_end = sampleRays.end();
772
773	// generate view cells
774	mGenerateViewCells = true;
775
776	long startTime = GetTime();
777
778	Debug << "** Extracting polygons from rays **\n";
779
780	std::map<Face , Polygon3 > facePolyMap;
781
782	//-- extract polygons intersected by the rays
783	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
784	{
785	Ray ray = rit;
786
787	// get ray-face intersection. Store polygon representing the rays together
788	// with rays intersecting the face.
789	if (!ray->intersections.empty())
790	{
791	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
792	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
793
794	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
795
796	if (it != facePolyMap.end())
797	{
798	//store rays if needed for heuristics
799	if (mSplitPlaneStrategy & BLOCKED_RAYS)
800	(*it).second->mPiercingRays.push_back(ray);
801	}
802	else
803	{ //store rays if needed for heuristics
804	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
805	poly->mParent = obj;
806	polys->push_back(poly);
807
808	if (mSplitPlaneStrategy & BLOCKED_RAYS)
809	poly->mPiercingRays.push_back(ray);
810
811	facePolyMap[face] = poly;
812	}
813	}
814	}
815
816	facePolyMap.clear();
817
818	// compute bounding box
819	if (!forcedBoundingBox)
820	Polygon3::IncludeInBox(*polys, mBox);
821
822	//-- store rays
823	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
824	{
825	Ray ray = rit;
826	ray->SetId(-1); // reset id
827
828	float minT, maxT;
829	if (mBox.GetRaySegment(*ray, minT, maxT))
830	rays->push_back(new BoundedRay(ray, minT, maxT));
831	}
832
833	// throw out bad polygons
834	PreprocessPolygons(*polys);
835
836	mStat.polys = (int)polys->size();
837
838	Debug << "** Finished polygon extraction **" << endl;
839	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
840	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
841
842	Construct(polys, rays);
843	}
844
845
846	void BspTree::Construct(const ObjectContainer &objects,
847	const RayContainer &sampleRays,
848	AxisAlignedBox3 *forcedBoundingBox)
849	{
850	mStat.nodes = 1;
851	mBox.Initialize(); // initialise BSP tree bounding box
852
853	if (forcedBoundingBox)
854	mBox = *forcedBoundingBox;
855
856	BoundedRayContainer *rays = new BoundedRayContainer();
857	PolygonContainer *polys = new PolygonContainer();
858
859	mGenerateViewCells = true;
860
861	// copy mesh instance polygons into one big polygon soup
862	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
863
864
865	RayContainer::const_iterator rit, rit_end = sampleRays.end();
866
867	//-- store rays
868	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
869	{
870	Ray ray = rit;
871	ray->SetId(-1); // reset id
872
873	float minT, maxT;
874	if (mBox.GetRaySegment(*ray, minT, maxT))
875	rays->push_back(new BoundedRay(ray, minT, maxT));
876	}
877
878	PreprocessPolygons(*polys);
879	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
880	Construct(polys, rays);
881	}
882
883
884	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
885	{
886	BspTraversalStack tStack;
887
888	mRoot = new BspLeaf();
889
890	// constrruct root node geometry
891	BspNodeGeometry *geom = new BspNodeGeometry();
892	ConstructGeometry(mRoot, *geom);
893
894	BspTraversalData tData(mRoot,
895	polys,
896	0,
897	GetOrCreateOutOfBoundsCell(),
898	rays,
899	ComputePvsSize(*rays),
900	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
901	geom);
902
903	mTotalCost = tData.mPvs * tData.mProbability / mBox.GetVolume();
904	mTotalPvsSize = tData.mPvs;
905
906	mSubdivisionStats
907	<< "#ViewCells\n1\n" << endl
908	<< "#RenderCostDecrease\n0\n" << endl
909	<< "#TotalRenderCost\n" << mTotalCost << endl
910	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
911
912	tStack.push(tData);
913
914	// used for intermediate time measurements and progress
915	long interTime = GetTime();
916	int nleaves = 500;
917
918	mStat.Start();
919	cout << "Constructing bsp tree ...\n";
920	long startTime = GetTime();
921	while (!tStack.empty())
922	{
923	tData = tStack.top();
924
925	tStack.pop();
926
927	// subdivide leaf node
928	BspNode *r = Subdivide(tStack, tData);
929
930	if (r == mRoot)
931	Debug << "BSP tree construction time spent at root: "
932	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
933
934	if (mStat.Leaves() >= nleaves)
935	{
936	nleaves += 500;
937
938	cout << "leaves=" << mStat.Leaves() << endl;
939	Debug << "needed "
940	<< TimeDiff(interTime, GetTime())*1e-3
941	<< " secs to create 500 leaves" << endl;
942	interTime = GetTime();
943	}
944	}
945
946	cout << "finished\n";
947
948	mStat.Stop();
949	}
950
951
952	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
953	{
954	return
955	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
956	((int)data.mRays->size() <= mTermMinRays) \|\|
957	(data.mPvs <= mTermMinPvs) \|\|
958	(data.mProbability <= mTermMinProbability) \|\|
959	(data.mDepth >= mTermMaxDepth) \|\|
960	(mStat.Leaves() >= mMaxViewCells) \|\|
961	(data.GetAvgRayContribution() > mTermMaxRayContribution));
962	}
963
964
965	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
966	{
967	//-- terminate traversal
968	if (TerminationCriteriaMet(tData))
969	{
970	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
971
972	BspViewCell *viewCell;
973
974	// generate new view cell for each leaf
975	if (mGenerateViewCells)
976	viewCell = new BspViewCell();
977	else
978	// add view cell to leaf
979	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
980
981	leaf->SetViewCell(viewCell);
982	viewCell->mLeaf = leaf;
983
984	//float probability = max(0.0f, tData.mProbability);
985	float probability = tData.mProbability;
986
987	if (mUseAreaForPvs)
988	viewCell->SetArea(probability);
989	else
990	viewCell->SetVolume(probability);
991
992	//-- add pvs
993	if (viewCell != mOutOfBoundsCell)
994	{
995	int conSamp = 0, sampCon = 0;
996	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
997
998	mStat.contributingSamples += conSamp;
999	mStat.sampleContributions += sampCon;
1000	}
1001
1002	EvaluateLeafStats(tData);
1003
1004	//-- clean up
1005
1006	// discard polygons
1007	CLEAR_CONTAINER(*tData.mPolygons);
1008	// discard rays
1009	CLEAR_CONTAINER(*tData.mRays);
1010
1011	DEL_PTR(tData.mPolygons);
1012	DEL_PTR(tData.mRays);
1013	DEL_PTR(tData.mGeometry);
1014
1015	return leaf;
1016	}
1017
1018	//-- continue subdivision
1019	PolygonContainer coincident;
1020
1021	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1022	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1023	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1024	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1025
1026
1027	// create new interior node and two leaf nodes
1028	BspInterior *interior =
1029	SubdivideNode(tData, tFrontData, tBackData, coincident);
1030
1031
1032	if (1)
1033	{
1034	int pvsData = tData.mPvs;
1035
1036	float cData = (float)pvsData * tData.mProbability;
1037	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1038	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1039
1040	float costDecr = (cFront + cBack - cData) / mBox.GetVolume();
1041
1042	mTotalCost += costDecr;
1043	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1044
1045	mSubdivisionStats
1046	<< "#ViewCells\n" << mStat.Leaves() << endl
1047	<< "#RenderCostDecrease\n" << -costDecr << endl
1048	<< "#TotalRenderCost\n" << mTotalCost << endl
1049	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1050	}
1051
1052	// extract view cells from coincident polygons according to plane normal
1053	// only if front or back polygons are empty
1054	if (!mGenerateViewCells)
1055	{
1056	ExtractViewCells(tFrontData,
1057	tBackData,
1058	coincident,
1059	interior->mPlane);
1060	}
1061
1062	// don't need coincident polygons anymory
1063	CLEAR_CONTAINER(coincident);
1064
1065	// push the children on the stack
1066	tStack.push(tFrontData);
1067	tStack.push(tBackData);
1068
1069	// cleanup
1070	DEL_PTR(tData.mNode);
1071
1072	DEL_PTR(tData.mPolygons);
1073	DEL_PTR(tData.mRays);
1074	DEL_PTR(tData.mGeometry);
1075
1076	return interior;
1077	}
1078
1079
1080	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1081	BspTraversalData &backData,
1082	const PolygonContainer &coincident,
1083	const Plane3 &splitPlane) const
1084	{
1085	// if not empty, tree is further subdivided => don't have to find view cell
1086	bool foundFront = !frontData.mPolygons->empty();
1087	bool foundBack = !frontData.mPolygons->empty();
1088
1089	PolygonContainer::const_iterator it =
1090	coincident.begin(), it_end = coincident.end();
1091
1092	//-- find first view cells in front and back leafs
1093	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1094	{
1095	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1096	{
1097	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1098	foundBack = true;
1099	}
1100	else
1101	{
1102	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1103	foundFront = true;
1104	}
1105	}
1106	}
1107
1108
1109	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1110	BspTraversalData &frontData,
1111	BspTraversalData &backData,
1112	PolygonContainer &coincident)
1113	{
1114	mStat.nodes += 2;
1115
1116	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1117
1118
1119
1120	// select subdivision plane
1121	BspInterior *interior =
1122	new BspInterior(SelectPlane(leaf, tData));
1123
1124
1125	#ifdef _DEBUG
1126	Debug << interior << endl;
1127	#endif
1128
1129
1130	// subdivide rays into front and back rays
1131	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1132
1133
1134
1135	// subdivide polygons with plane
1136	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1137	*tData.mPolygons,
1138	*frontData.mPolygons,
1139	*backData.mPolygons,
1140	coincident);
1141
1142
1143
1144	// compute pvs
1145	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1146	backData.mPvs = ComputePvsSize(*backData.mRays);
1147
1148	// split geometry and compute area
1149	if (1)
1150	{
1151	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1152	*backData.mGeometry,
1153	interior->mPlane,
1154	mBox,
1155	//0.000000000001);
1156	mEpsilon);
1157
1158
1159	if (mUseAreaForPvs)
1160	{
1161	frontData.mProbability = frontData.mGeometry->GetArea();
1162	backData.mProbability = backData.mGeometry->GetArea();
1163	}
1164	else
1165	{
1166	frontData.mProbability = frontData.mGeometry->GetVolume();
1167	backData.mProbability = tData.mProbability - frontData.mProbability;
1168	}
1169	}
1170
1171	//-- create front and back leaf
1172
1173	BspInterior *parent = leaf->GetParent();
1174
1175	// replace a link from node's parent
1176	if (!leaf->IsRoot())
1177	{
1178	parent->ReplaceChildLink(leaf, interior);
1179	interior->SetParent(parent);
1180	}
1181	else // new root
1182	{
1183	mRoot = interior;
1184	}
1185
1186	// and setup child links
1187	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1188
1189	frontData.mNode = interior->GetFront();
1190	backData.mNode = interior->GetBack();
1191
1192	interior->mTimeStamp = mTimeStamp ++;
1193
1194	//DEL_PTR(leaf);
1195	return interior;
1196	}
1197
1198
1199	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1200	const int axis,
1201	vector<SortableEntry> &splitCandidates) const
1202	{
1203	splitCandidates.clear();
1204
1205	int requestedSize = 2 * (int)polys.size();
1206	// creates a sorted split candidates array
1207	splitCandidates.reserve(requestedSize);
1208
1209	PolygonContainer::const_iterator it, it_end = polys.end();
1210
1211	AxisAlignedBox3 box;
1212
1213	// insert all queries
1214	for(it = polys.begin(); it != it_end; ++ it)
1215	{
1216	box.Initialize();
1217	box.Include((it));
1218
1219	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1220	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1221	}
1222
1223	stable_sort(splitCandidates.begin(), splitCandidates.end());
1224	}
1225
1226
1227	float BspTree::BestCostRatio(const PolygonContainer &polys,
1228	const AxisAlignedBox3 &box,
1229	const int axis,
1230	float &position,
1231	int &objectsBack,
1232	int &objectsFront) const
1233	{
1234	vector<SortableEntry> splitCandidates;
1235
1236	SortSplitCandidates(polys, axis, splitCandidates);
1237
1238	// go through the lists, count the number of objects left and right
1239	// and evaluate the following cost funcion:
1240	// C = ct_div_ci + (ol + or)/queries
1241
1242	int objectsLeft = 0, objectsRight = (int)polys.size();
1243
1244	float minBox = box.Min(axis);
1245	float maxBox = box.Max(axis);
1246	float boxArea = box.SurfaceArea();
1247
1248	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1249	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1250
1251	float minSum = 1e20f;
1252	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1253
1254	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1255	{
1256	switch ((*ci).type)
1257	{
1258	case SortableEntry::POLY_MIN:
1259	++ objectsLeft;
1260	break;
1261	case SortableEntry::POLY_MAX:
1262	-- objectsRight;
1263	break;
1264	default:
1265	break;
1266	}
1267
1268	if ((ci).value > minBand && (ci).value < maxBand)
1269	{
1270	AxisAlignedBox3 lbox = box;
1271	AxisAlignedBox3 rbox = box;
1272	lbox.SetMax(axis, (*ci).value);
1273	rbox.SetMin(axis, (*ci).value);
1274
1275	const float sum = objectsLeft * lbox.SurfaceArea() +
1276	objectsRight * rbox.SurfaceArea();
1277
1278	if (sum < minSum)
1279	{
1280	minSum = sum;
1281	position = (*ci).value;
1282
1283	objectsBack = objectsLeft;
1284	objectsFront = objectsRight;
1285	}
1286	}
1287	}
1288
1289	const float oldCost = (float)polys.size();
1290	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1291	const float ratio = newCost / oldCost;
1292
1293
1294	#if 0
1295	Debug << "====================" << endl;
1296	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1297	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1298	#endif
1299	return ratio;
1300	}
1301
1302	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1303	const PolygonContainer &polys) const
1304	{
1305	AxisAlignedBox3 box;
1306	box.Initialize();
1307
1308	// create bounding box of region
1309	Polygon3::IncludeInBox(polys, box);
1310
1311	int objectsBack = 0, objectsFront = 0;
1312	int axis = 0;
1313	float costRatio = MAX_FLOAT;
1314	Vector3 position;
1315
1316	//-- area subdivision
1317	for (int i = 0; i < 3; ++ i)
1318	{
1319	float p = 0;
1320	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1321
1322	if (r < costRatio)
1323	{
1324	costRatio = r;
1325	axis = i;
1326	position = p;
1327	}
1328	}
1329
1330	if (costRatio >= mMaxCostRatio)
1331	return false;
1332
1333	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1334	plane = Plane3(norm, position);
1335
1336	return true;
1337	}
1338
1339
1340	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1341	{
1342	if ((!mMaxPolyCandidates \|\| data.mPolygons->empty()) &&
1343	(!mMaxRayCandidates \|\| data.mRays->empty()))
1344	{
1345	Debug << "Warning: No autopartition polygon candidate available\n";
1346
1347	// return axis aligned split
1348	AxisAlignedBox3 box;
1349	box.Initialize();
1350
1351	// create bounding box of region
1352	Polygon3::IncludeInBox(*data.mPolygons, box);
1353
1354	const int axis = box.Size().DrivingAxis();
1355	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1356
1357	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1358	return Plane3(norm, position);
1359	}
1360
1361	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1362	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1363	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1364	((mTermMinObjectsForAxisAligned < 0) \|\|
1365	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1366	{
1367	Plane3 plane;
1368	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1369	return plane;
1370	}
1371
1372	// simplest strategy: just take next polygon
1373	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1374	{
1375	if (!data.mPolygons->empty())
1376	{
1377	Polygon3 *nextPoly =
1378	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1379	return nextPoly->GetSupportingPlane();
1380	}
1381	else
1382	{
1383	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1384	BoundedRay bRay = (data.mRays)[candidateIdx];
1385
1386	Ray *ray = bRay->mRay;
1387
1388	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1389	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1390
1391	const Vector3 pt = (maxPt + minPt) * 0.5;
1392
1393	const Vector3 normal = ray->GetDir();
1394
1395	return Plane3(normal, pt);
1396	}
1397
1398	return Plane3();
1399	}
1400
1401	// use heuristics to find appropriate plane
1402	return SelectPlaneHeuristics(leaf, data);
1403	}
1404
1405
1406	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1407	{
1408	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1409	BoundedRay *bRay = rays[candidateIdx];
1410	Ray *ray = bRay->mRay;
1411
1412	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1413	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1414
1415	const Vector3 pt = (maxPt + minPt) * 0.5;
1416
1417	const Vector3 normal = ray->GetDir();
1418
1419	return Plane3(normal, pt);
1420	}
1421
1422	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1423	{
1424	Vector3 pt[3];
1425	int idx[3];
1426	int cmaxT = 0;
1427	int cminT = 0;
1428	bool chooseMin = false;
1429
1430	for (int j = 0; j < 3; j ++)
1431	{
1432	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1433
1434	if (idx[j] >= (int)rays.size())
1435	{
1436	idx[j] -= (int)rays.size();
1437	chooseMin = (cminT < 2);
1438	}
1439	else
1440	chooseMin = (cmaxT < 2);
1441
1442	BoundedRay *bRay = rays[idx[j]];
1443	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1444	bRay->mRay->Extrap(bRay->mMaxT);
1445	}
1446
1447	return Plane3(pt[0], pt[1], pt[2]);
1448	}
1449
1450	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1451	{
1452	Vector3 pt[3];
1453
1454	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1455	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1456
1457	// check if rays different
1458	if (idx1 == idx2)
1459	idx2 = (idx2 + 1) % (int)rays.size();
1460
1461	const BoundedRay *ray1 = rays[idx1];
1462	const BoundedRay *ray2 = rays[idx2];
1463
1464	// normal vector of the plane parallel to both lines
1465	const Vector3 norm =
1466	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1467
1468	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1469	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1470
1471	// vector from line 1 to line 2
1472	const Vector3 vd = orig1 - orig2;
1473
1474	// project vector on normal to get distance
1475	const float dist = DotProd(vd, norm);
1476
1477	// point on plane lies halfway between the two planes
1478	const Vector3 planePt = orig1 + norm * dist * 0.5;
1479
1480	return Plane3(norm, planePt);
1481	}
1482
1483
1484	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1485	{
1486	float lowestCost = MAX_FLOAT;
1487	Plane3 bestPlane;
1488	// intermediate plane
1489	Plane3 plane;
1490
1491	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1492	int maxIdx = (int)data.mPolygons->size();
1493
1494	for (int i = 0; i < limit; ++ i)
1495	{
1496	// assure that no index is taken twice
1497	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1498
1499	Polygon3 poly = (data.mPolygons)[candidateIdx];
1500
1501	// swap candidate to the end to avoid testing same plane
1502	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1503	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1504
1505	// evaluate current candidate
1506	const float candidateCost =
1507	SplitPlaneCost(poly->GetSupportingPlane(), data);
1508
1509	if (candidateCost < lowestCost)
1510	{
1511	bestPlane = poly->GetSupportingPlane();
1512	lowestCost = candidateCost;
1513	}
1514	}
1515
1516	//-- choose candidate planes extracted from rays
1517	for (int i = 0; i < mMaxRayCandidates; ++ i)
1518	{
1519	plane = ChooseCandidatePlane3(*data.mRays);
1520	const float candidateCost = SplitPlaneCost(plane, data);
1521
1522	if (candidateCost < lowestCost)
1523	{
1524	bestPlane = plane;
1525	lowestCost = candidateCost;
1526	}
1527	}
1528
1529	#ifdef _DEBUG
1530	Debug << "plane lowest cost: " << lowestCost << endl;
1531	#endif
1532
1533	return bestPlane;
1534	}
1535
1536
1537	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1538	const PolygonContainer &polys) const
1539	{
1540	float val = 0;
1541
1542	float sumBalancedPolys = 0;
1543	float sumSplits = 0;
1544	float sumPolyArea = 0;
1545	float sumBalancedViewCells = 0;
1546	float sumBlockedRays = 0;
1547	float totalBlockedRays = 0;
1548	//float totalArea = 0;
1549	int totalViewCells = 0;
1550
1551	// need three unique ids for each type of view cell
1552	// for balanced view cells criterium
1553	ViewCell::NewMail();
1554	const int backId = ViewCell::sMailId;
1555	ViewCell::NewMail();
1556	const int frontId = ViewCell::sMailId;
1557	ViewCell::NewMail();
1558	const int frontAndBackId = ViewCell::sMailId;
1559
1560	bool useRand;
1561	int limit;
1562
1563	// choose test polyongs randomly if over threshold
1564	if ((int)polys.size() > mMaxTests)
1565	{
1566	useRand = true;
1567	limit = mMaxTests;
1568	}
1569	else
1570	{
1571	useRand = false;
1572	limit = (int)polys.size();
1573	}
1574
1575	for (int i = 0; i < limit; ++ i)
1576	{
1577	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1578
1579	Polygon3 *poly = polys[testIdx];
1580
1581	const int classification =
1582	poly->ClassifyPlane(candidatePlane, mEpsilon);
1583
1584	if (mSplitPlaneStrategy & BALANCED_POLYS)
1585	sumBalancedPolys += sBalancedPolysTable[classification];
1586
1587	if (mSplitPlaneStrategy & LEAST_SPLITS)
1588	sumSplits += sLeastPolySplitsTable[classification];
1589
1590	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1591	{
1592	if (classification == Polygon3::COINCIDENT)
1593	sumPolyArea += poly->GetArea();
1594	//totalArea += area;
1595	}
1596
1597	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1598	{
1599	const float blockedRays = (float)poly->mPiercingRays.size();
1600
1601	if (classification == Polygon3::COINCIDENT)
1602	sumBlockedRays += blockedRays;
1603
1604	totalBlockedRays += blockedRays;
1605	}
1606
1607	// assign view cells to back or front according to classificaion
1608	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1609	{
1610	MeshInstance *viewCell = poly->mParent;
1611
1612	// assure that we only count a view cell
1613	// once for the front and once for the back side of the plane
1614	if (classification == Polygon3::FRONT_SIDE)
1615	{
1616	if ((viewCell->mMailbox != frontId) &&
1617	(viewCell->mMailbox != frontAndBackId))
1618	{
1619	sumBalancedViewCells += 1.0;
1620
1621	if (viewCell->mMailbox != backId)
1622	viewCell->mMailbox = frontId;
1623	else
1624	viewCell->mMailbox = frontAndBackId;
1625
1626	++ totalViewCells;
1627	}
1628	}
1629	else if (classification == Polygon3::BACK_SIDE)
1630	{
1631	if ((viewCell->mMailbox != backId) &&
1632	(viewCell->mMailbox != frontAndBackId))
1633	{
1634	sumBalancedViewCells -= 1.0;
1635
1636	if (viewCell->mMailbox != frontId)
1637	viewCell->mMailbox = backId;
1638	else
1639	viewCell->mMailbox = frontAndBackId;
1640
1641	++ totalViewCells;
1642	}
1643	}
1644	}
1645	}
1646
1647	const float polysSize = (float)polys.size() + Limits::Small;
1648
1649	// all values should be approx. between 0 and 1 so they can be combined
1650	// and scaled with the factors according to their importance
1651	if (mSplitPlaneStrategy & BALANCED_POLYS)
1652	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1653
1654	if (mSplitPlaneStrategy & LEAST_SPLITS)
1655	val += mLeastSplitsFactor * sumSplits / polysSize;
1656
1657	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1658	// HACK: polys.size should be total area so scaling is between 0 and 1
1659	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1660
1661	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1662	if (totalBlockedRays != 0)
1663	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1664
1665	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1666	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1667	((float)totalViewCells + Limits::Small);
1668
1669	return val;
1670	}
1671
1672
1673	inline void BspTree::GenerateUniqueIdsForPvs()
1674	{
1675	ViewCell::NewMail(); sBackId = ViewCell::sMailId;
1676	ViewCell::NewMail(); sFrontId = ViewCell::sMailId;
1677	ViewCell::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1678	}
1679
1680
1681	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1682	const BoundedRayContainer &rays,
1683	const int pvs,
1684	const float probability,
1685	const BspNodeGeometry &cell) const
1686	{
1687	float val = 0;
1688
1689	float sumBalancedRays = 0;
1690	float sumRaySplits = 0;
1691
1692	int frontPvs = 0;
1693	int backPvs = 0;
1694
1695	// probability that view point lies in child
1696	float pOverall = 0;
1697	float pFront = 0;
1698	float pBack = 0;
1699
1700	const bool pvsUseLen = false;
1701
1702	if (mSplitPlaneStrategy & PVS)
1703	{
1704	// create unique ids for pvs heuristics
1705	GenerateUniqueIdsForPvs();
1706
1707	// construct child geometry with regard to the candidate split plane
1708	BspNodeGeometry frontCell;
1709	BspNodeGeometry backCell;
1710
1711	cell.SplitGeometry(frontCell,
1712	backCell,
1713	candidatePlane,
1714	mBox,
1715	mEpsilon);
1716
1717	if (mUseAreaForPvs)
1718	{
1719	pFront = frontCell.GetArea();
1720	pBack = backCell.GetArea();
1721	}
1722	else
1723	{
1724	pFront = frontCell.GetVolume();
1725	pBack = pOverall - pFront;
1726	}
1727
1728
1729	pOverall = probability;
1730	}
1731
1732	bool useRand;
1733	int limit;
1734
1735	// choose test polyongs randomly if over threshold
1736	if ((int)rays.size() > mMaxTests)
1737	{
1738	useRand = true;
1739	limit = mMaxTests;
1740	}
1741	else
1742	{
1743	useRand = false;
1744	limit = (int)rays.size();
1745	}
1746
1747	for (int i = 0; i < limit; ++ i)
1748	{
1749	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1750
1751	BoundedRay *bRay = rays[testIdx];
1752
1753	Ray *ray = bRay->mRay;
1754	const float minT = bRay->mMinT;
1755	const float maxT = bRay->mMaxT;
1756
1757	Vector3 entP, extP;
1758
1759	const int cf =
1760	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1761
1762	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1763	{
1764	sumBalancedRays += sBalancedRaysTable[cf];
1765	}
1766
1767	if (mSplitPlaneStrategy & BALANCED_RAYS)
1768	{
1769	sumRaySplits += sLeastRaySplitsTable[cf];
1770	}
1771
1772	if (mSplitPlaneStrategy & PVS)
1773	{
1774	// in case the ray intersects an object
1775	// assure that we only count the object
1776	// once for the front and once for the back side of the plane
1777
1778	// add the termination object
1779	if (!ray->intersections.empty())
1780	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1781
1782	// add the source object
1783	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1784	}
1785	}
1786
1787	const float raysSize = (float)rays.size() + Limits::Small;
1788
1789	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1790	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1791
1792	if (mSplitPlaneStrategy & BALANCED_RAYS)
1793	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1794
1795	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1796
1797	if (mSplitPlaneStrategy & PVS)
1798	{
1799	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1800
1801	// give penalty to unbalanced split
1802	if (0)
1803	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1804	(pFront < (pBack * 0.2 + Limits::Small)))
1805	val += 0.5;
1806	}
1807
1808
1809	#ifdef _DEBUG
1810	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1811	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1812	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1813	#endif
1814
1815	return val;
1816	}
1817
1818	void BspTree::AddObjToPvs(Intersectable *obj,
1819	const int cf,
1820	int &frontPvs,
1821	int &backPvs) const
1822	{
1823	if (!obj)
1824	return;
1825	// TODO: does this really belong to no pvs?
1826	//if (cf == Ray::COINCIDENT) return;
1827
1828	// object belongs to both PVS
1829	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1830	(cf == Ray::BACK_FRONT) \|\|
1831	(cf == Ray::COINCIDENT);
1832
1833	if ((cf == Ray::FRONT) \|\| bothSides)
1834	{
1835	if ((obj->mMailbox != sFrontId) &&
1836	(obj->mMailbox != sFrontAndBackId))
1837	{
1838	++ frontPvs;
1839
1840	if (obj->mMailbox == sBackId)
1841	obj->mMailbox = sFrontAndBackId;
1842	else
1843	obj->mMailbox = sFrontId;
1844	}
1845	}
1846
1847	if ((cf == Ray::BACK) \|\| bothSides)
1848	{
1849	if ((obj->mMailbox != sBackId) &&
1850	(obj->mMailbox != sFrontAndBackId))
1851	{
1852	++ backPvs;
1853
1854	if (obj->mMailbox == sFrontId)
1855	obj->mMailbox = sFrontAndBackId;
1856	else
1857	obj->mMailbox = sBackId;
1858	}
1859	}
1860	}
1861
1862
1863	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1864	BspTraversalData &data) const
1865	{
1866	float val = 0;
1867
1868	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1869	{
1870	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1871	// we put a penalty on the dot product between the "tiny" vertical axis
1872	// and the split plane axis
1873	val += mVerticalSplitsFactor *
1874	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1875	}
1876
1877	// the following criteria loop over all polygons to find the cost value
1878	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1879	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1880	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1881	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1882	(mSplitPlaneStrategy & BLOCKED_RAYS))
1883	{
1884	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1885	}
1886
1887	// the following criteria loop over all rays to find the cost value
1888	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1889	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1890	(mSplitPlaneStrategy & PVS))
1891	{
1892	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1893	data.mProbability, *data.mGeometry);
1894	}
1895
1896	// return linear combination of the sums
1897	return val;
1898	}
1899
1900	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1901	{
1902	stack<BspNode *> nodeStack;
1903	nodeStack.push(mRoot);
1904
1905	while (!nodeStack.empty())
1906	{
1907	BspNode *node = nodeStack.top();
1908
1909	nodeStack.pop();
1910
1911	if (node->IsLeaf())
1912	{
1913	BspLeaf leaf = (BspLeaf )node;
1914	leaves.push_back(leaf);
1915	}
1916	else
1917	{
1918	BspInterior interior = dynamic_cast<BspInterior >(node);
1919
1920	nodeStack.push(interior->GetBack());
1921	nodeStack.push(interior->GetFront());
1922	}
1923	}
1924	}
1925
1926
1927	AxisAlignedBox3 BspTree::GetBoundingBox() const
1928	{
1929	return mBox;
1930	}
1931
1932
1933	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1934	{
1935	// the node became a leaf -> evaluate stats for leafs
1936	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1937
1938	// store maximal and minimal depth
1939	if (data.mDepth > mStat.maxDepth)
1940	mStat.maxDepth = data.mDepth;
1941
1942	if (data.mDepth < mStat.minDepth)
1943	mStat.minDepth = data.mDepth;
1944
1945	// accumulate depth to compute average depth
1946	mStat.accumDepth += data.mDepth;
1947	// accumulate rays to compute rays / leaf
1948	mStat.accumRays += (int)data.mRays->size();
1949
1950	if (data.mDepth >= mTermMaxDepth)
1951	++ mStat.maxDepthNodes;
1952
1953	if (data.mPvs < mTermMinPvs)
1954	++ mStat.minPvsNodes;
1955
1956	if ((int)data.mRays->size() < mTermMinRays)
1957	++ mStat.minRaysNodes;
1958
1959	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1960	++ mStat.maxRayContribNodes;
1961
1962	if (data.mProbability <= mTermMinProbability)
1963	++ mStat.minProbabilityNodes;
1964
1965	#ifdef _DEBUG
1966	Debug << "BSP stats: "
1967	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1968	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1969	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
1970	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1971	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1972	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1973	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1974	#endif
1975	}
1976
1977	int
1978	BspTree::_CastRay(Ray &ray)
1979	{
1980	int hits = 0;
1981
1982	stack<BspRayTraversalData> tStack;
1983
1984	float maxt, mint;
1985
1986	if (!mBox.GetRaySegment(ray, mint, maxt))
1987	return 0;
1988
1989	ViewCell::NewMail();
1990
1991	Vector3 entp = ray.Extrap(mint);
1992	Vector3 extp = ray.Extrap(maxt);
1993
1994	BspNode *node = mRoot;
1995	BspNode *farChild = NULL;
1996
1997	while (1)
1998	{
1999	if (!node->IsLeaf())
2000	{
2001	BspInterior in = dynamic_cast<BspInterior >(node);
2002
2003	Plane3 splitPlane = in->GetPlane();
2004	const int entSide = splitPlane.Side(entp);
2005	const int extSide = splitPlane.Side(extp);
2006
2007	if (entSide < 0)
2008	{
2009	node = in->GetBack();
2010
2011	if(extSide <= 0) // plane does not split ray => no far child
2012	continue;
2013
2014	farChild = in->GetFront(); // plane splits ray
2015
2016	} else if (entSide > 0)
2017	{
2018	node = in->GetFront();
2019
2020	if (extSide >= 0) // plane does not split ray => no far child
2021	continue;
2022
2023	farChild = in->GetBack(); // plane splits ray
2024	}
2025	else // ray and plane are coincident
2026	{
2027	// WHAT TO DO IN THIS CASE ?
2028	//break;
2029	node = in->GetFront();
2030	continue;
2031	}
2032
2033	// push data for far child
2034	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2035
2036	// find intersection of ray segment with plane
2037	float t;
2038	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
2039	maxt *= t;
2040
2041	} else // reached leaf => intersection with view cell
2042	{
2043	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2044
2045	if (!leaf->mViewCell->Mailed())
2046	{
2047	//ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
2048	leaf->mViewCell->Mail();
2049	++ hits;
2050	}
2051
2052	//-- fetch the next far child from the stack
2053	if (tStack.empty())
2054	break;
2055
2056	entp = extp;
2057	mint = maxt; // NOTE: need this?
2058
2059	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
2060	break;
2061
2062	BspRayTraversalData &s = tStack.top();
2063
2064	node = s.mNode;
2065	extp = s.mExitPoint;
2066	maxt = s.mMaxT;
2067
2068	tStack.pop();
2069	}
2070	}
2071
2072	return hits;
2073	}
2074
2075
2076	int BspTree::CastLineSegment(const Vector3 &origin,
2077	const Vector3 &termination,
2078	vector<ViewCell *> &viewcells)
2079	{
2080	int hits = 0;
2081	stack<BspRayTraversalData> tStack;
2082
2083	float mint = 0.0f, maxt = 1.0f;
2084
2085	Intersectable::NewMail();
2086	ViewCell::NewMail();
2087
2088	Vector3 entp = origin;
2089	Vector3 extp = termination;
2090
2091	BspNode *node = mRoot;
2092	BspNode *farChild = NULL;
2093
2094	const float thresh = 1 ? 1e-6f : 0.0f;
2095
2096	while (1)
2097	{
2098	if (!node->IsLeaf())
2099	{
2100	BspInterior in = dynamic_cast<BspInterior >(node);
2101
2102	Plane3 splitPlane = in->GetPlane();
2103
2104	const int entSide = splitPlane.Side(entp, thresh);
2105	const int extSide = splitPlane.Side(extp, thresh);
2106
2107	if (entSide < 0)
2108	{
2109	node = in->GetBack();
2110
2111	if(extSide <= 0) // plane does not split ray => no far child
2112	continue;
2113
2114	farChild = in->GetFront(); // plane splits ray
2115
2116	}
2117	else if (entSide > 0)
2118	{
2119	node = in->GetFront();
2120
2121	if (extSide >= 0) // plane does not split ray => no far child
2122	continue;
2123
2124	farChild = in->GetBack(); // plane splits ray
2125	}
2126	else // ray and plane are coincident
2127	{
2128	// NOTE: what to do if ray is coincident with plane?
2129	if (extSide < 0)
2130	node = in->GetBack();
2131	else //if (extSide > 0)
2132	node = in->GetFront();
2133	//else break;
2134
2135	continue; // no far child
2136	}
2137
2138	// push data for far child
2139	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2140
2141	// find intersection of ray segment with plane
2142	float t;
2143	extp = splitPlane.FindIntersection(origin, extp, &t);
2144	maxt *= t;
2145	}
2146	else
2147	{
2148	// reached leaf => intersection with view cell
2149	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2150
2151	if (!leaf->mViewCell->Mailed())
2152	{
2153	viewcells.push_back(leaf->mViewCell);
2154	leaf->mViewCell->Mail();
2155	hits++;
2156	}
2157
2158	//-- fetch the next far child from the stack
2159	if (tStack.empty())
2160	break;
2161
2162	entp = extp;
2163	mint = maxt; // NOTE: need this?
2164
2165	BspRayTraversalData &s = tStack.top();
2166
2167	node = s.mNode;
2168	extp = s.mExitPoint;
2169	maxt = s.mMaxT;
2170
2171	tStack.pop();
2172	}
2173	}
2174	return hits;
2175	}
2176
2177
2178	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2179	{
2180	stack<BspNode *> nodeStack;
2181	nodeStack.push(mRoot);
2182
2183	ViewCell::NewMail();
2184
2185	while (!nodeStack.empty())
2186	{
2187	BspNode *node = nodeStack.top();
2188	nodeStack.pop();
2189
2190	if (node->IsLeaf())
2191	{
2192	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2193
2194	if (!viewCell->Mailed())
2195	{
2196	viewCell->Mail();
2197	viewCells.push_back(viewCell);
2198	}
2199	}
2200	else
2201	{
2202	BspInterior interior = dynamic_cast<BspInterior >(node);
2203
2204	nodeStack.push(interior->GetFront());
2205	nodeStack.push(interior->GetBack());
2206	}
2207	}
2208	}
2209
2210
2211	BspTreeStatistics &BspTree::GetStat()
2212	{
2213	return mStat;
2214	}
2215
2216
2217	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2218	{
2219	float len = 0;
2220
2221	BoundedRayContainer::const_iterator it, it_end = rays.end();
2222
2223	for (it = rays.begin(); it != it_end; ++ it)
2224	{
2225	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2226	(it)->mRay->Extrap((it)->mMaxT));
2227	}
2228
2229	return len;
2230	}
2231
2232
2233	int BspTree::SplitRays(const Plane3 &plane,
2234	BoundedRayContainer &rays,
2235	BoundedRayContainer &frontRays,
2236	BoundedRayContainer &backRays)
2237	{
2238	int splits = 0;
2239
2240	while (!rays.empty())
2241	{
2242	BoundedRay *bRay = rays.back();
2243	Ray *ray = bRay->mRay;
2244	float minT = bRay->mMinT;
2245	float maxT = bRay->mMaxT;
2246
2247	rays.pop_back();
2248
2249	Vector3 entP, extP;
2250
2251	const int cf =
2252	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2253
2254	// set id to ray classification
2255	ray->SetId(cf);
2256
2257	switch (cf)
2258	{
2259	case Ray::COINCIDENT: // TODO: should really discard ray?
2260	frontRays.push_back(bRay);
2261	//DEL_PTR(bRay);
2262	break;
2263	case Ray::BACK:
2264	backRays.push_back(bRay);
2265	break;
2266	case Ray::FRONT:
2267	frontRays.push_back(bRay);
2268	break;
2269	case Ray::FRONT_BACK:
2270	{
2271	// find intersection of ray segment with plane
2272	const float t = plane.FindT(ray->GetLoc(), extP);
2273
2274	const float newT = t * maxT;
2275
2276	frontRays.push_back(new BoundedRay(ray, minT, newT));
2277	backRays.push_back(new BoundedRay(ray, newT, maxT));
2278
2279	DEL_PTR(bRay);
2280	}
2281	break;
2282	case Ray::BACK_FRONT:
2283	{
2284	// find intersection of ray segment with plane
2285	const float t = plane.FindT(ray->GetLoc(), extP);
2286	const float newT = t * bRay->mMaxT;
2287
2288	backRays.push_back(new BoundedRay(ray, minT, newT));
2289	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2290
2291	DEL_PTR(bRay);
2292
2293	++ splits;
2294	}
2295	break;
2296	default:
2297	Debug << "Should not come here 4" << endl;
2298	break;
2299	}
2300	}
2301
2302	return splits;
2303	}
2304
2305	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2306	{
2307	BspNode *lastNode;
2308
2309	do
2310	{
2311	lastNode = n;
2312
2313	// want to get planes defining geometry of this node => don't take
2314	// split plane of node itself
2315	n = n->GetParent();
2316
2317	if (n)
2318	{
2319	BspInterior interior = dynamic_cast<BspInterior >(n);
2320	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2321
2322	if (interior->GetBack() != lastNode)
2323	halfSpace.ReverseOrientation();
2324
2325	halfSpaces.push_back(halfSpace);
2326	}
2327	}
2328	while (n);
2329	}
2330
2331
2332
2333	void BspTree::ConstructGeometry(ViewCell *vc,
2334	BspNodeGeometry &vcGeom) const
2335	{
2336	ViewCellContainer leaves;
2337	mViewCellsTree->CollectLeaves(vc, leaves);
2338
2339	ViewCellContainer::const_iterator it, it_end = leaves.end();
2340
2341	for (it = leaves.begin(); it != it_end; ++ it)
2342	{
2343	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2344	ConstructGeometry(l, vcGeom);
2345	}
2346	}
2347
2348
2349	void BspTree::ConstructGeometry(BspNode *n,
2350	BspNodeGeometry &geom) const
2351	{
2352	vector<Plane3> halfSpaces;
2353	ExtractHalfSpaces(n, halfSpaces);
2354
2355	PolygonContainer candidatePolys;
2356	vector<Plane3> candidatePlanes;
2357
2358	// bounded planes are added to the polygons
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	candidatePolys.push_back(p);
2366	candidatePlanes.push_back(halfSpaces[i]);
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	Polygon3 *poly = new Polygon3(vertices);
2379
2380	candidatePolys.push_back(poly);
2381	candidatePlanes.push_back(poly->GetSupportingPlane());
2382	}
2383
2384	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2385	{
2386	// polygon is split by all other planes
2387	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2388	{
2389	if (i == j) // polygon and plane are coincident
2390	continue;
2391
2392	VertexContainer splitPts;
2393	Polygon3 frontPoly, backPoly;
2394
2395	const int cf =
2396	candidatePolys[i]->ClassifyPlane(halfSpaces[j],
2397	mEpsilon);
2398
2399	switch (cf)
2400	{
2401	case Polygon3::SPLIT:
2402	frontPoly = new Polygon3();
2403	backPoly = new Polygon3();
2404
2405	candidatePolys[i]->Split(halfSpaces[j],
2406	*frontPoly,
2407	*backPoly,
2408	mEpsilon);
2409
2410	DEL_PTR(candidatePolys[i]);
2411
2412	if (frontPoly->Valid(mEpsilon))
2413	candidatePolys[i] = frontPoly;
2414	else
2415	DEL_PTR(frontPoly);
2416
2417	DEL_PTR(backPoly);
2418	break;
2419	// polygon outside of halfspace
2420	case Polygon3::FRONT_SIDE:
2421	DEL_PTR(candidatePolys[i]);
2422	break;
2423	// just take polygon as it is
2424	case Polygon3::BACK_SIDE:
2425	case Polygon3::COINCIDENT:
2426	default:
2427	break;
2428	}
2429	}
2430
2431	if (candidatePolys[i])
2432	{
2433	geom.Add(candidatePolys[i], candidatePlanes[i]);
2434	// geom.mPolys.push_back(candidates[i]);
2435	}
2436	}
2437	}
2438
2439
2440	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2441	{
2442	mViewCellsManager = vcm;
2443	}
2444
2445
2446	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2447
2448
2449	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf >
2450	&neighbors,
2451	const bool onlyUnmailed) const
2452	{
2453	stack<bspNodePair> nodeStack;
2454
2455	BspNodeGeometry nodeGeom;
2456	ConstructGeometry(n, nodeGeom);
2457
2458	// split planes from the root to this node
2459	// needed to verify that we found neighbor leaf
2460	// TODO: really needed?
2461	vector<Plane3> halfSpaces;
2462	ExtractHalfSpaces(n, halfSpaces);
2463
2464
2465	BspNodeGeometry *rgeom = new BspNodeGeometry();
2466	ConstructGeometry(mRoot, *rgeom);
2467
2468	nodeStack.push(bspNodePair(mRoot, rgeom));
2469
2470	while (!nodeStack.empty())
2471	{
2472	BspNode *node = nodeStack.top().first;
2473	BspNodeGeometry *geom = nodeStack.top().second;
2474
2475	nodeStack.pop();
2476
2477	if (node->IsLeaf())
2478	{
2479	// test if this leaf is in valid view space
2480	if (node->TreeValid() &&
2481	(node != n) &&
2482	(!onlyUnmailed \|\| !node->Mailed()))
2483	{
2484	bool isAdjacent = true;
2485
2486	if (1)
2487	{
2488	// test all planes of current node if still adjacent
2489	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2490	{
2491	const int cf =
2492	Polygon3::ClassifyPlane(geom->GetPolys(),
2493	halfSpaces[i],
2494	mEpsilon);
2495
2496	if (cf == Polygon3::FRONT_SIDE)
2497	{
2498	isAdjacent = false;
2499	}
2500	}
2501	}
2502	else
2503	{
2504	// TODO: why is this wrong??
2505	// test all planes of current node if still adjacent
2506	for (int i = 0; (i < nodeGeom.Size()) && isAdjacent; ++ i)
2507	{
2508	Polygon3 *poly = nodeGeom.GetPolys()[i];
2509
2510	const int cf =
2511	Polygon3::ClassifyPlane(geom->GetPolys(),
2512	poly->GetSupportingPlane(),
2513	mEpsilon);
2514
2515	if (cf == Polygon3::FRONT_SIDE)
2516	{
2517	isAdjacent = false;
2518	}
2519	}
2520	}
2521	// neighbor was found
2522	if (isAdjacent)
2523	{
2524	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2525	}
2526	}
2527	}
2528	else
2529	{
2530	BspInterior interior = dynamic_cast<BspInterior >(node);
2531
2532	const int cf = Polygon3::ClassifyPlane(nodeGeom.GetPolys(),
2533	interior->GetPlane(),
2534	mEpsilon);
2535
2536	BspNode *front = interior->GetFront();
2537	BspNode *back = interior->GetBack();
2538
2539	BspNodeGeometry *fGeom = new BspNodeGeometry();
2540	BspNodeGeometry *bGeom = new BspNodeGeometry();
2541
2542	geom->SplitGeometry(*fGeom,
2543	*bGeom,
2544	interior->GetPlane(),
2545	mBox,
2546	//0.0000001f);
2547	mEpsilon);
2548
2549	if (cf == Polygon3::BACK_SIDE)
2550	{
2551	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2552	DEL_PTR(fGeom);
2553	}
2554	else
2555	{
2556	if (cf == Polygon3::FRONT_SIDE)
2557	{
2558	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2559	DEL_PTR(bGeom);
2560	}
2561	else
2562	{ // random decision
2563	nodeStack.push(bspNodePair(front, fGeom));
2564	nodeStack.push(bspNodePair(back, bGeom));
2565	}
2566	}
2567	}
2568
2569	DEL_PTR(geom);
2570	}
2571
2572	return (int)neighbors.size();
2573	}
2574
2575
2576	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2577	{
2578	stack<BspNode *> nodeStack;
2579
2580	nodeStack.push(mRoot);
2581
2582	int mask = rand();
2583
2584	while (!nodeStack.empty())
2585	{
2586	BspNode *node = nodeStack.top();
2587	nodeStack.pop();
2588
2589	if (node->IsLeaf())
2590	{
2591	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2592	return dynamic_cast<BspLeaf *>(node);
2593	}
2594	else
2595	{
2596	BspInterior interior = dynamic_cast<BspInterior >(node);
2597
2598	// random decision
2599	if (mask & 1)
2600	nodeStack.push(interior->GetBack());
2601	else
2602	nodeStack.push(interior->GetFront());
2603
2604	mask = mask >> 1;
2605	}
2606	}
2607
2608	return NULL;
2609	}
2610
2611
2612	void BspTree::AddToPvs(BspLeaf *leaf,
2613	const BoundedRayContainer &rays,
2614	int &sampleContributions,
2615	int &contributingSamples)
2616	{
2617	sampleContributions = 0;
2618	contributingSamples = 0;
2619
2620	BoundedRayContainer::const_iterator it, it_end = rays.end();
2621
2622	ViewCell *vc = leaf->GetViewCell();
2623
2624	// add contributions from samples to the PVS
2625	for (it = rays.begin(); it != it_end; ++ it)
2626	{
2627	int contribution = 0;
2628	Ray ray = (it)->mRay;
2629	float relContribution;
2630	if (!ray->intersections.empty())
2631	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2632	1.0f,
2633	relContribution);
2634
2635	if (ray->sourceObject.mObject)
2636	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2637	1.0f,
2638	relContribution);
2639
2640	if (contribution)
2641	{
2642	sampleContributions += contribution;
2643	++ contributingSamples;
2644	}
2645
2646	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2647	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2648	}
2649	}
2650
2651
2652	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2653	{
2654	int pvsSize = 0;
2655
2656	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2657
2658	Intersectable::NewMail();
2659
2660	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2661	{
2662	Ray ray = (rit)->mRay;
2663
2664	if (!ray->intersections.empty())
2665	{
2666	if (!ray->intersections[0].mObject->Mailed())
2667	{
2668	ray->intersections[0].mObject->Mail();
2669	++ pvsSize;
2670	}
2671	}
2672	if (ray->sourceObject.mObject)
2673	{
2674	if (!ray->sourceObject.mObject->Mailed())
2675	{
2676	ray->sourceObject.mObject->Mail();
2677	++ pvsSize;
2678	}
2679	}
2680	}
2681
2682	return pvsSize;
2683	}
2684
2685
2686	float BspTree::GetEpsilon() const
2687	{
2688	return mEpsilon;
2689	}
2690
2691
2692	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2693	vector<MergeCandidate> &candidates)
2694	{
2695	BspLeaf::NewMail();
2696
2697	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2698
2699	int numCandidates = 0;
2700
2701	// find merge candidates and push them into queue
2702	for (it = leaves.begin(); it != it_end; ++ it)
2703	{
2704	BspLeaf leaf = it;
2705
2706	// the same leaves must not be part of two merge candidates
2707	leaf->Mail();
2708	vector<BspLeaf *> neighbors;
2709	FindNeighbors(leaf, neighbors, true);
2710
2711	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2712
2713	// TODO: test if at least one ray goes from one leaf to the other
2714	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2715	{
2716	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2717	{
2718	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2719	candidates.push_back(mc);
2720
2721	++ numCandidates;
2722	if ((numCandidates % 1000) == 0)
2723	{
2724	cout << "collected " << numCandidates << " merge candidates" << endl;
2725	}
2726	}
2727	}
2728	}
2729
2730	Debug << "merge queue: " << (int)candidates.size() << endl;
2731	Debug << "leaves in queue: " << numCandidates << endl;
2732
2733
2734	return (int)leaves.size();
2735	}
2736
2737
2738	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2739	vector<MergeCandidate> &candidates)
2740	{
2741	ViewCell::NewMail();
2742	long startTime = GetTime();
2743
2744	map<BspLeaf , vector<BspLeaf> > neighborMap;
2745	ViewCellContainer::const_iterator iit;
2746
2747	int numLeaves = 0;
2748
2749	BspLeaf::NewMail();
2750
2751	for (int i = 0; i < (int)rays.size(); ++ i)
2752	{
2753	VssRay *ray = rays[i];
2754
2755	// traverse leaves stored in the rays and compare and
2756	// merge consecutive leaves (i.e., the neighbors in the tree)
2757	if (ray->mViewCells.size() < 2)
2758	continue;
2759
2760	iit = ray->mViewCells.begin();
2761	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2762	BspLeaf *leaf = bspVc->mLeaf;
2763
2764	// traverse intersections
2765	// consecutive leaves are neighbors => add them to queue
2766	for (; iit != ray->mViewCells.end(); ++ iit)
2767	{
2768	// next pair
2769	BspLeaf *prevLeaf = leaf;
2770	bspVc = dynamic_cast<BspViewCell >(iit);
2771	leaf = bspVc->mLeaf;
2772
2773	// view space not valid or same view cell
2774	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2775	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2776	continue;
2777
2778	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2779
2780	bool found = false;
2781
2782	// both leaves inserted in queue already =>
2783	// look if double pair already exists
2784	if (leaf->Mailed() && prevLeaf->Mailed())
2785	{
2786	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2787
2788	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2789	if (*it == prevLeaf)
2790	found = true; // already in queue
2791	}
2792
2793	if (!found)
2794	{
2795	// this pair is not in map yet
2796	// => insert into the neighbor map and the queue
2797	neighbors.push_back(prevLeaf);
2798	neighborMap[prevLeaf].push_back(leaf);
2799
2800	leaf->Mail();
2801	prevLeaf->Mail();
2802
2803	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2804
2805	candidates.push_back(mc);
2806
2807	if (((int)candidates.size() % 1000) == 0)
2808	{
2809	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2810	}
2811	}
2812	}
2813	}
2814
2815	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2816	Debug << "merge queue: " << (int)candidates.size() << endl;
2817	Debug << "leaves in queue: " << numLeaves << endl;
2818
2819
2820	//-- collect the leaves which haven't been found by ray casting
2821	#if 0
2822	cout << "finding additional merge candidates using geometry" << endl;
2823	vector<BspLeaf *> leaves;
2824	CollectLeaves(leaves, true);
2825	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2826	CollectMergeCandidates(leaves, candidates);
2827	#endif
2828
2829	return numLeaves;
2830	}
2831
2832
2833
2834
2835	/***************************************************************/
2836	/* BspNodeGeometry Implementation */
2837	/***************************************************************/
2838
2839
2840	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2841	{
2842	mPolys.reserve(rhs.mPolys.size());
2843	mPlanes.reserve(rhs.mPolys.size());
2844
2845
2846	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2847
2848	int i = 0;
2849
2850	for (it = rhs.mPolys.begin(); it != it_end; ++ it, ++i)
2851	{
2852	Polygon3 poly = it;
2853	Add(new Polygon3(*poly), rhs.mPlanes[i]);
2854	}
2855	}
2856
2857
2858	BspNodeGeometry& BspNodeGeometry::operator=(const BspNodeGeometry& g)
2859	{
2860	if (this == &g)
2861	return *this;
2862
2863	CLEAR_CONTAINER(mPolys);
2864
2865	mPolys.reserve(g.mPolys.size());
2866	mPlanes.reserve(g.mPolys.size());
2867
2868	PolygonContainer::const_iterator it, it_end = g.mPolys.end();
2869
2870	int i = 0;
2871
2872	for (it = g.mPolys.begin(); it != it_end; ++ it, ++ i)
2873	{
2874	Polygon3 poly = it;
2875	Add(new Polygon3(*poly), g.mPlanes[i]);
2876	}
2877
2878	return *this;
2879	}
2880
2881
2882	BspNodeGeometry::BspNodeGeometry(const PolygonContainer &polys)
2883	{
2884	mPolys = polys;
2885	mPlanes.reserve(polys.size());
2886
2887	PolygonContainer::const_iterator it, it_end = polys.end();
2888
2889	for (it = polys.begin(); it != it_end; ++ it)
2890	{
2891	Polygon3 poly = it;
2892	mPlanes.push_back(poly->GetSupportingPlane());
2893	}
2894	}
2895
2896
2897	BspNodeGeometry::~BspNodeGeometry()
2898	{
2899	CLEAR_CONTAINER(mPolys);
2900	}
2901
2902
2903	int BspNodeGeometry::Size() const
2904	{
2905	return (int)mPolys.size();
2906	}
2907
2908
2909	const PolygonContainer &BspNodeGeometry::GetPolys()
2910	{
2911	return mPolys;
2912	}
2913
2914
2915	void BspNodeGeometry::Add(Polygon3 *p, const Plane3 &plane)
2916	{
2917	mPolys.push_back(p);
2918	mPlanes.push_back(plane);
2919	}
2920
2921
2922	float BspNodeGeometry::GetArea() const
2923	{
2924	return Polygon3::GetArea(mPolys);
2925	}
2926
2927
2928	float BspNodeGeometry::GetVolume() const
2929	{
2930	//-- compute volume using tetrahedralization of the geometry
2931	// and adding the volume of the single tetrahedrons
2932	float volume = 0;
2933	const float f = 1.0f / 6.0f;
2934
2935	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2936
2937	// note: can take arbitrary point, e.g., the origin. However,
2938	// we rather take the center of mass to prevents precision errors
2939	const Vector3 center = CenterOfMass();
2940
2941	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2942	{
2943	Polygon3 poly = pit;
2944	const Vector3 v0 = poly->mVertices[0] - center;
2945
2946	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2947	{
2948	const Vector3 v1 = poly->mVertices[i] - center;
2949	const Vector3 v2 = poly->mVertices[i + 1] - center;
2950
2951	// more robust version using abs and the center of mass
2952	volume += fabs (f * (DotProd(v0, CrossProd(v1, v2))));
2953	}
2954	}
2955
2956	return volume;
2957	}
2958
2959
2960	void BspNodeGeometry::GetBoundingBox(AxisAlignedBox3 &box) const
2961	{
2962	box.Initialize();
2963	Polygon3::IncludeInBox(mPolys, box);
2964	}
2965
2966
2967	int BspNodeGeometry::Side(const Plane3 &plane, const float eps) const
2968	{
2969	PolygonContainer::const_iterator it, it_end = mPolys.end();
2970
2971	bool onFrontSide = false;
2972	bool onBackSide = false;
2973
2974	for (it = mPolys.begin(); it != it_end; ++ it)
2975	{
2976	const int side = (*it)->Side(plane, eps);
2977
2978	if (side == -1)
2979	onBackSide = true;
2980	else if (side == 1)
2981	onFrontSide = true;
2982
2983	if ((side == 0) \|\| (onBackSide && onFrontSide))
2984	return 0;
2985	}
2986
2987	if (onFrontSide)
2988	return 1;
2989
2990	return -1;
2991	}
2992
2993
2994	int BspNodeGeometry::ComputeIntersection(const AxisAlignedBox3 &box) const
2995	{
2996	// 1: box does not intersect geometry
2997	// 0: box intersects geometry
2998	// -1: box contains geometry
2999
3000	AxisAlignedBox3 boundingBox;
3001	GetBoundingBox(boundingBox);
3002
3003	// no intersections with bounding box
3004	if (!Overlap(box, boundingBox))
3005	{
3006	return 1;
3007	}
3008
3009	// box cotains bounding box of geometry >=> contains geometry
3010	if (box.Includes(boundingBox))
3011	return -1;
3012
3013	int result = 0;
3014
3015	// test geometry planes for intersections
3016	vector<Plane3>::const_iterator it, it_end = mPlanes.end();
3017
3018	for (it = mPlanes.begin(); it != it_end; ++ it)
3019	{
3020	const int side = box.Side(*it);
3021
3022	// box does not intersects geometry
3023	if (side == 1)
3024	{
3025	return 1;
3026	}
3027	//if (side == 0) result = 0;
3028	}
3029
3030	return result;
3031	}
3032
3033
3034	Vector3 BspNodeGeometry::CenterOfMass() const
3035	{
3036	int n = 0;
3037
3038	Vector3 center(0,0,0);
3039
3040	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
3041
3042	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
3043	{
3044	Polygon3 poly = pit;
3045
3046	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
3047
3048	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
3049	{
3050	center += *vit;
3051	++ n;
3052	}
3053	}
3054
3055	//Debug << "center: " << center << " new " << center / (float)n << endl;
3056
3057	return center / (float)n;
3058	}
3059
3060
3061	bool BspNodeGeometry::Valid() const
3062	{
3063	if (mPolys.size() < 4)
3064	return false;
3065
3066	return true;
3067	}
3068
3069
3070	void BspNodeGeometry::AddToMesh(Mesh &mesh)
3071	{
3072	PolygonContainer::const_iterator it, it_end = mPolys.end();
3073
3074	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
3075	{
3076	(*it)->AddToMesh(mesh);
3077	}
3078	}
3079
3080
3081	bool BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
3082	BspNodeGeometry &back,
3083	const Plane3 &splitPlane,
3084	const AxisAlignedBox3 &box,
3085	const float epsilon) const
3086	{
3087	#if 0
3088	// trivial cases
3089	const int cf = Side(splitPlane, epsilon);
3090
3091	if (cf == -1)
3092	{
3093	back = *this;
3094	return false;
3095	}
3096	else if (cf == 1)
3097	{
3098	front = *this;
3099	return false;
3100	}
3101	#endif
3102
3103	// get cross section of new polygon
3104	Polygon3 *planePoly = box.CrossSection(splitPlane);
3105
3106	// split polygon with all other polygons
3107	planePoly = SplitPolygon(planePoly, epsilon);
3108
3109	bool splitsGeom = (planePoly != NULL);
3110
3111	//-- new polygon splits all other polygons
3112	for (int i = 0; i < (int)mPolys.size()/* && planePoly*/; ++ i)
3113	{
3114	/// don't use epsilon here to get exact split planes
3115	const int cf =
3116	mPolys[i]->ClassifyPlane(splitPlane, epsilon);
3117
3118	switch (cf)
3119	{
3120	case Polygon3::SPLIT:
3121	{
3122	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
3123
3124	Polygon3 *frontPoly = new Polygon3();
3125	Polygon3 *backPoly = new Polygon3();
3126
3127	poly->Split(splitPlane,
3128	*frontPoly,
3129	*backPoly,
3130	epsilon);
3131
3132	DEL_PTR(poly);
3133
3134	if (frontPoly->Valid(epsilon))
3135	{
3136	front.Add(frontPoly, mPlanes[i]);
3137	}
3138	else
3139	{
3140	//Debug << "no f! " << endl;
3141	DEL_PTR(frontPoly);
3142	}
3143
3144	if (backPoly->Valid(epsilon))
3145	{
3146	back.Add(backPoly, mPlanes[i]);
3147	}
3148	else
3149	{
3150	//Debug << "no b! " << endl;
3151	DEL_PTR(backPoly);
3152	}
3153	}
3154
3155	break;
3156	case Polygon3::BACK_SIDE:
3157	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3158	break;
3159	case Polygon3::FRONT_SIDE:
3160	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3161	break;
3162	// only put into back container (split should have no effect ...)
3163	case Polygon3::COINCIDENT:
3164	//Debug << "error should not come here" << endl;
3165	splitsGeom = false;
3166
3167	if (DotProd(mPlanes[i].mNormal, splitPlane.mNormal > 0))
3168	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3169	else
3170	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3171	break;
3172	default:
3173	break;
3174	}
3175	}
3176
3177	//-- finally add the new polygon to the child node geometries
3178	if (planePoly)
3179	{
3180	// add polygon with reverse orientation to front cell
3181	Plane3 reversePlane(splitPlane);
3182	reversePlane.ReverseOrientation();
3183
3184	// add polygon with normal pointing into positive half space to back cell
3185	back.Add(planePoly, splitPlane);
3186	//back.mPolys.push_back(planePoly);
3187
3188	Polygon3 *reversePoly = planePoly->CreateReversePolygon();
3189	front.Add(reversePoly, reversePlane);
3190	//Debug << "poly normal : " << reversePoly->GetSupportingPlane().mNormal << " split plane normal " << reversePlane.mNormal << endl;
3191	}
3192
3193
3194	return splitsGeom;
3195	}
3196
3197
3198	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3199	const float epsilon) const
3200	{
3201	if (!planePoly->Valid(epsilon))
3202	{
3203	//Debug << "not valid!!" << endl;
3204	DEL_PTR(planePoly);
3205	}
3206	// polygon is split by all other planes
3207	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3208	{
3209	//Plane3 plane = mPolys[i]->GetSupportingPlane();
3210	Plane3 plane = mPlanes[i];
3211
3212	/// don't use epsilon here to get exact split planes
3213	const int cf =
3214	planePoly->ClassifyPlane(plane, epsilon);
3215
3216	// split new polygon with all previous planes
3217	switch (cf)
3218	{
3219	case Polygon3::SPLIT:
3220	{
3221	Polygon3 *frontPoly = new Polygon3();
3222	Polygon3 *backPoly = new Polygon3();
3223
3224	planePoly->Split(plane,
3225	*frontPoly,
3226	*backPoly,
3227	epsilon);
3228
3229	// don't need anymore
3230	DEL_PTR(planePoly);
3231	DEL_PTR(frontPoly);
3232
3233	// back polygon is belonging to geometry
3234	if (backPoly->Valid(epsilon))
3235	planePoly = backPoly;
3236	else
3237	DEL_PTR(backPoly);
3238	}
3239	break;
3240	case Polygon3::FRONT_SIDE:
3241	DEL_PTR(planePoly);
3242	break;
3243	// polygon is taken as it is
3244	case Polygon3::BACK_SIDE:
3245	case Polygon3::COINCIDENT:
3246	default:
3247	break;
3248	}
3249	}
3250
3251	return planePoly;
3252	}
3253
3254
3255	ViewCell *BspTree::GetViewCell(const Vector3 &point)
3256	{
3257	if (mRoot == NULL)
3258	return NULL;
3259
3260
3261	stack<BspNode *> nodeStack;
3262	nodeStack.push(mRoot);
3263
3264	ViewCell *viewcell = NULL;
3265
3266	while (!nodeStack.empty()) {
3267	BspNode *node = nodeStack.top();
3268	nodeStack.pop();
3269
3270	if (node->IsLeaf()) {
3271	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3272	break;
3273	} else {
3274
3275	BspInterior interior = dynamic_cast<BspInterior >(node);
3276
3277	// random decision
3278	if (interior->GetPlane().Side(point) < 0)
3279	nodeStack.push(interior->GetBack());
3280	else
3281	nodeStack.push(interior->GetFront());
3282	}
3283	}
3284
3285	return viewcell;
3286	}
3287
3288
3289	bool BspTree::Export(ofstream &stream)
3290	{
3291	ExportNode(mRoot, stream);
3292
3293	return true;
3294	}
3295
3296
3297	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3298	{
3299	if (node->IsLeaf())
3300	{
3301	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3302
3303	int id = -1;
3304	if (leaf->GetViewCell() != mOutOfBoundsCell)
3305	id = leaf->GetViewCell()->GetId();
3306
3307	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3308	}
3309	else
3310	{
3311	BspInterior interior = dynamic_cast<BspInterior >(node);
3312
3313	Plane3 plane = interior->GetPlane();
3314	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3315	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3316	<< plane.mD << "\">" << endl;
3317
3318	ExportNode(interior->GetBack(), stream);
3319	ExportNode(interior->GetFront(), stream);
3320
3321	stream << "</Interior>" << endl;
3322	}
3323	}

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