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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 535

Revision 535, 67.6 KB checked in by mattausch, 19 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include "Triangle3.h"
11
12	#include <stack>
13
14	#include "Exporter.h"
15	#include "Plane3.h"
16
17	//-- static members
18
19	int BspNode::sMailId = 1;
20
21	/** Evaluates split plane classification with respect to the plane's
22	contribution for a minimum number splits in the tree.
23	*/
24	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
25	/** Evaluates split plane classification with respect to the plane's
26	contribution for a balanced tree.
27	*/
28	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
29
30	/** Evaluates split plane classification with respect to the plane's
31	contribution for a minimum number of ray splits.
32	*/
33	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
34	/** Evaluates split plane classification with respect to the plane's
35	contribution for balanced rays.
36	*/
37	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
38
39	int BspTree::sFrontId = 0;
40	int BspTree::sBackId = 0;
41	int BspTree::sFrontAndBackId = 0;
42
43
44	/****************************************************************/
45	/* class BspNode implementation */
46	/****************************************************************/
47
48
49	BspNode::BspNode():
50	mParent(NULL), mTreeValid(true)
51	{}
52
53	BspNode::BspNode(BspInterior *parent):
54	mParent(parent), mTreeValid(true)
55	{}
56
57
58	bool BspNode::IsRoot() const
59	{
60	return mParent == NULL;
61	}
62
63
64	BspInterior *BspNode::GetParent()
65	{
66	return mParent;
67	}
68
69
70	void BspNode::SetParent(BspInterior *parent)
71	{
72	mParent = parent;
73	}
74
75
76	bool BspNode::IsSibling(BspNode *n) const
77	{
78	return ((this != n) && mParent &&
79	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
80	}
81
82
83	int BspNode::GetDepth() const
84	{
85	int depth = 0;
86	BspNode *p = mParent;
87
88	while (p)
89	{
90	p = p->mParent;
91	++ depth;
92	}
93
94	return depth;
95	}
96
97
98	bool BspNode::TreeValid() const
99	{
100	return mTreeValid;
101	}
102
103
104	void BspNode::SetTreeValid(const bool v)
105	{
106	mTreeValid = v;
107	}
108
109
110	/****************************************************************/
111	/* class BspInterior implementation */
112	/****************************************************************/
113
114
115	BspInterior::BspInterior(const Plane3 &plane):
116	mPlane(plane), mFront(NULL), mBack(NULL)
117	{}
118
119	BspInterior::~BspInterior()
120	{
121	DEL_PTR(mFront);
122	DEL_PTR(mBack);
123	}
124
125	bool BspInterior::IsLeaf() const
126	{
127	return false;
128	}
129
130	BspNode *BspInterior::GetBack()
131	{
132	return mBack;
133	}
134
135	BspNode *BspInterior::GetFront()
136	{
137	return mFront;
138	}
139
140	Plane3 BspInterior::GetPlane() const
141	{
142	return mPlane;
143	}
144
145	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
146	{
147	if (mBack == oldChild)
148	mBack = newChild;
149	else
150	mFront = newChild;
151	}
152
153	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
154	{
155	mBack = b;
156	mFront = f;
157	}
158
159	/****************************************************************/
160	/* class BspLeaf implementation */
161	/****************************************************************/
162
163
164	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
165	{
166	}
167
168
169	BspLeaf::~BspLeaf()
170	{
171	DEL_PTR(mPvs);
172	}
173
174
175	BspLeaf::BspLeaf(BspViewCell *viewCell):
176	mViewCell(viewCell)
177	{
178	}
179
180
181	BspLeaf::BspLeaf(BspInterior *parent):
182	BspNode(parent), mViewCell(NULL), mPvs(NULL)
183	{}
184
185
186
187	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
188	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
189	{
190	}
191
192	BspViewCell *BspLeaf::GetViewCell() const
193	{
194	return mViewCell;
195	}
196
197	void BspLeaf::SetViewCell(BspViewCell *viewCell)
198	{
199	mViewCell = viewCell;
200	}
201
202	bool BspLeaf::IsLeaf() const
203	{
204	return true;
205	}
206
207	/****************************************************************/
208	/* class BspTree implementation */
209	/****************************************************************/
210
211	BspTree::BspTree():
212	mRoot(NULL),
213	mPvsUseArea(true),
214	mGenerateViewCells(true)
215	{
216	Randomize(); // initialise random generator for heuristics
217
218	// the view cell corresponding to unbounded space
219	mRootCell = new BspViewCell();
220
221	//-- termination criteria for autopartition
222	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
223	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
224	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
225	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
226	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
227	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
228	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
229
230	//-- factors for bsp tree split plane heuristics
231	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
232	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
233	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
234	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
235	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
236	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
237	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
238	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
239	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
240	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
241
242	//-- termination criteria for axis aligned split
243	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
244	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
245	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
246	mTermMinPolysForAxisAligned);
247	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
248	mTermMinRaysForAxisAligned);
249	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
250	mTermMinObjectsForAxisAligned);
251	//-- partition criteria
252	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
253	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
254	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
255	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
256	environment->GetIntValue("BspTree.maxTests", mMaxTests);
257
258	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
259
260	Debug << "BSP max depth: " << mTermMaxDepth << endl;
261	Debug << "BSP min PVS: " << mTermMinPvs << endl;
262	Debug << "BSP min area: " << mTermMinArea << endl;
263	Debug << "BSP max polys: " << mTermMinPolys << endl;
264	Debug << "BSP max rays: " << mTermMinRays << endl;
265	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
266	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
267
268	Debug << "Split plane strategy: ";
269	if (mSplitPlaneStrategy & RANDOM_POLYGON)
270	Debug << "random polygon ";
271	if (mSplitPlaneStrategy & AXIS_ALIGNED)
272	Debug << "axis aligned ";
273	if (mSplitPlaneStrategy & LEAST_SPLITS)
274	Debug << "least splits ";
275	if (mSplitPlaneStrategy & BALANCED_POLYS)
276	Debug << "balanced polygons ";
277	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
278	Debug << "balanced view cells ";
279	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
280	Debug << "largest polygon area ";
281	if (mSplitPlaneStrategy & VERTICAL_AXIS)
282	Debug << "vertical axis ";
283	if (mSplitPlaneStrategy & BLOCKED_RAYS)
284	Debug << "blocked rays ";
285	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
286	Debug << "least ray splits ";
287	if (mSplitPlaneStrategy & BALANCED_RAYS)
288	Debug << "balanced rays ";
289	if (mSplitPlaneStrategy & PVS)
290	Debug << "pvs";
291
292	Debug << endl;
293	}
294
295
296	const BspTreeStatistics &BspTree::GetStatistics() const
297	{
298	return mStat;
299	}
300
301
302	int BspTree::SplitPolygons(const Plane3 &plane,
303	PolygonContainer &polys,
304	PolygonContainer &frontPolys,
305	PolygonContainer &backPolys,
306	PolygonContainer &coincident) const
307	{
308	int splits = 0;
309
310	#ifdef _Debug
311	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
312	#endif
313	while (!polys.empty())
314	{
315	Polygon3 *poly = polys.back();
316	polys.pop_back();
317
318	//-- classify polygon
319	const int cf = poly->ClassifyPlane(plane, mEpsilon);
320
321	switch (cf)
322	{
323	case Polygon3::COINCIDENT:
324	coincident.push_back(poly);
325	break;
326	case Polygon3::FRONT_SIDE:
327	frontPolys.push_back(poly);
328	break;
329	case Polygon3::BACK_SIDE:
330	backPolys.push_back(poly);
331	break;
332	case Polygon3::SPLIT:
333	{
334	Polygon3 *front_piece = new Polygon3(poly->mParent);
335	Polygon3 *back_piece = new Polygon3(poly->mParent);
336
337	//-- split polygon into front and back part
338	poly->Split(plane,
339	*front_piece,
340	*back_piece,
341	mEpsilon);
342
343	++ splits; // increase number of splits
344
345	//-- inherit rays from parent polygon for blocked ray criterium
346	poly->InheritRays(front_piece, back_piece);
347
348	// check if polygons still valid
349	if (front_piece->Valid(mEpsilon))
350	frontPolys.push_back(front_piece);
351	else
352	DEL_PTR(front_piece);
353
354	if (back_piece->Valid(mEpsilon))
355	backPolys.push_back(back_piece);
356	else
357	DEL_PTR(back_piece);
358
359	#ifdef _DEBUG
360	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
361	#endif
362	DEL_PTR(poly);
363	}
364	break;
365	default:
366	Debug << "SHOULD NEVER COME HERE\n";
367	break;
368	}
369	}
370
371	return splits;
372	}
373
374
375	void BspTreeStatistics::Print(ostream &app) const
376	{
377	app << "===== BspTree statistics ===============\n";
378
379	app << setprecision(4);
380
381	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
382
383	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
384
385	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
386
387	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
388
389	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
390
391	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
392
393	app << "#N_SPLITS ( Number of splits in axes x y z\n";
394
395	for (int i = 0; i < 3; ++ i)
396	app << splits[i] << " ";
397	app << endl;
398
399	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
400	<< maxDepthNodes * 100 / (double)Leaves() << endl;
401
402	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
403	<< minPvsNodes * 100 / (double)Leaves() << endl;
404
405	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
406	<< minRaysNodes * 100 / (double)Leaves() << endl;
407
408	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
409	<< maxCostNodes * 100 / (double)Leaves() << endl;
410
411	app << "#N_PMINAREALEAVES ( Percentage of leaves with mininum area )\n"
412	<< minAreaNodes * 100 / (double)Leaves() << endl;
413
414	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
415	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
416
417	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
418
419	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
420
421	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
422
423	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
424
425	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
426
427	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
428	//app << "#N_PVS: " << pvs << endl;
429
430	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
431	(polys + polySplits) / (double)polys << endl;
432
433	app << "===== END OF BspTree statistics ==========\n";
434	}
435
436
437	BspTree::~BspTree()
438	{
439	DEL_PTR(mRoot);
440
441	// HACK: view cells not generated => root cell not used
442	if (mGenerateViewCells)
443	DEL_PTR(mRootCell);
444	}
445
446	BspViewCell *BspTree::GetRootCell() const
447	{
448	return mRootCell;
449	}
450
451	void BspTree::InsertViewCell(ViewCell *viewCell)
452	{
453	PolygonContainer *polys = new PolygonContainer();
454
455	// don't generate new view cell, insert this one
456	mGenerateViewCells = false;
457	// extract polygons that guide the split process
458	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
459	mBox.Include(viewCell->GetBox()); // add to BSP aabb
460
461	InsertPolygons(polys);
462	}
463
464	void BspTree::InsertPolygons(PolygonContainer *polys)
465	{
466	BspTraversalStack tStack;
467
468	// traverse existing tree or create new tree
469	if (!mRoot)
470	mRoot = new BspLeaf();
471
472	tStack.push(BspTraversalData(mRoot,
473	polys,
474	0,
475	mRootCell,
476	new BoundedRayContainer(),
477	0,
478	mBox.SurfaceArea(),
479	new BspNodeGeometry()));
480
481	while (!tStack.empty())
482	{
483	// filter polygons donw the tree
484	BspTraversalData tData = tStack.top();
485	tStack.pop();
486
487	if (!tData.mNode->IsLeaf())
488	{
489	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
490
491	//-- filter view cell polygons down the tree until a leaf is reached
492	if (!tData.mPolygons->empty())
493	{
494	PolygonContainer *frontPolys = new PolygonContainer();
495	PolygonContainer *backPolys = new PolygonContainer();
496	PolygonContainer coincident;
497
498	int splits = 0;
499
500	// split viewcell polygons with respect to split plane
501	splits += SplitPolygons(interior->GetPlane(),
502	*tData.mPolygons,
503	*frontPolys,
504	*backPolys,
505	coincident);
506
507	// extract view cells associated with the split polygons
508	ViewCell *frontViewCell = mRootCell;
509	ViewCell *backViewCell = mRootCell;
510
511	BspTraversalData frontData(interior->GetFront(),
512	frontPolys,
513	tData.mDepth + 1,
514	mRootCell,
515	tData.mRays,
516	tData.mPvs,
517	mBox.SurfaceArea(),
518	new BspNodeGeometry());
519
520	BspTraversalData backData(interior->GetBack(),
521	backPolys,
522	tData.mDepth + 1,
523	mRootCell,
524	tData.mRays,
525	tData.mPvs,
526	mBox.SurfaceArea(),
527	new BspNodeGeometry());
528
529	if (!mGenerateViewCells)
530	{
531	ExtractViewCells(frontData,
532	backData,
533	coincident,
534	interior->mPlane);
535	}
536
537	// don't need coincident polygons anymore
538	CLEAR_CONTAINER(coincident);
539
540	mStat.polySplits += splits;
541
542	// push the children on the stack
543	tStack.push(frontData);
544	tStack.push(backData);
545	}
546
547	// cleanup
548	DEL_PTR(tData.mPolygons);
549	DEL_PTR(tData.mRays);
550	}
551	else
552	{
553	// reached leaf => subdivide current viewcell
554	BspNode *subRoot = Subdivide(tStack, tData);
555	}
556	}
557	}
558
559	int BspTree::AddMeshToPolygons(Mesh *mesh,
560	PolygonContainer &polys,
561	MeshInstance *parent)
562	{
563	FaceContainer::const_iterator fi;
564
565	// copy the face data to polygons
566	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
567	{
568	Polygon3 poly = new Polygon3((fi), mesh);
569
570	if (poly->Valid(mEpsilon))
571	{
572	poly->mParent = parent; // set parent intersectable
573	polys.push_back(poly);
574	}
575	else
576	DEL_PTR(poly);
577	}
578	return (int)mesh->mFaces.size();
579	}
580
581	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
582	PolygonContainer &polys,
583	int maxObjects)
584	{
585	int limit = (maxObjects > 0) ?
586	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
587
588	int polysSize = 0;
589
590	for (int i = 0; i < limit; ++ i)
591	{
592	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
593	{
594	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
595	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
596	}
597	}
598
599	return polysSize;
600	}
601
602	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
603	{
604	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
605
606	for (int i = 0; i < limit; ++i)
607	{
608	Intersectable object = objects[i];//it;
609	Mesh *mesh = NULL;
610
611	switch (object->Type()) // extract the meshes
612	{
613	case Intersectable::MESH_INSTANCE:
614	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
615	break;
616	case Intersectable::VIEW_CELL:
617	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
618	break;
619	// TODO: handle transformed mesh instances
620	default:
621	Debug << "intersectable type not supported" << endl;
622	break;
623	}
624
625	if (mesh) // copy the mesh data to polygons
626	{
627	mBox.Include(object->GetBox()); // add to BSP tree aabb
628	AddMeshToPolygons(mesh, polys, mRootCell);
629	}
630	}
631
632	return (int)polys.size();
633	}
634
635	void BspTree::Construct(const ViewCellContainer &viewCells)
636	{
637	mStat.nodes = 1;
638	mBox.Initialize(); // initialise bsp tree bounding box
639
640	// copy view cell meshes into one big polygon soup
641	PolygonContainer *polys = new PolygonContainer();
642	mStat.polys = AddToPolygonSoup(viewCells, *polys);
643
644	// view cells are given
645	mGenerateViewCells = false;
646	// construct tree from the view cell polygons
647	Construct(polys, new BoundedRayContainer());
648	}
649
650
651	void BspTree::Construct(const ObjectContainer &objects)
652	{
653	mStat.nodes = 1;
654	mBox.Initialize(); // initialise bsp tree bounding box
655
656	PolygonContainer *polys = new PolygonContainer();
657
658	mGenerateViewCells = true;
659	// copy mesh instance polygons into one big polygon soup
660	mStat.polys = AddToPolygonSoup(objects, *polys);
661
662	// construct tree from polygon soup
663	Construct(polys, new BoundedRayContainer());
664	}
665
666	void BspTree::Construct(const RayContainer &sampleRays)
667	{
668	mStat.nodes = 1;
669	mBox.Initialize(); // initialise BSP tree bounding box
670
671	PolygonContainer *polys = new PolygonContainer();
672	BoundedRayContainer *rays = new BoundedRayContainer();
673
674	RayContainer::const_iterator rit, rit_end = sampleRays.end();
675
676	// generate view cells
677	mGenerateViewCells = true;
678
679	long startTime = GetTime();
680
681	Debug << "** Extracting polygons from rays **\n";
682
683	std::map<Face , Polygon3 > facePolyMap;
684
685	//-- extract polygons intersected by the rays
686	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
687	{
688	Ray ray = rit;
689
690	// get ray-face intersection. Store polygon representing the rays together
691	// with rays intersecting the face.
692	if (!ray->intersections.empty())
693	{
694	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
695	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
696
697	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
698
699	if (it != facePolyMap.end())
700	{
701	//store rays if needed for heuristics
702	if (mSplitPlaneStrategy & BLOCKED_RAYS)
703	(*it).second->mPiercingRays.push_back(ray);
704	}
705	else
706	{ //store rays if needed for heuristics
707	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
708	poly->mParent = obj;
709	polys->push_back(poly);
710
711	if (mSplitPlaneStrategy & BLOCKED_RAYS)
712	poly->mPiercingRays.push_back(ray);
713
714	facePolyMap[face] = poly;
715	}
716	}
717	}
718
719	facePolyMap.clear();
720
721	// compute bounding box
722	Polygon3::IncludeInBox(*polys, mBox);
723
724	//-- store rays
725	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
726	{
727	Ray ray = rit;
728	ray->SetId(-1); // reset id
729
730	float minT, maxT;
731	if (mBox.GetRaySegment(*ray, minT, maxT))
732	rays->push_back(new BoundedRay(ray, minT, maxT));
733	}
734
735	mStat.polys = (int)polys->size();
736
737	Debug << "** Finished polygon extraction **" << endl;
738	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
739	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
740
741	Construct(polys, rays);
742	}
743
744	void BspTree::Construct(const ObjectContainer &objects, const RayContainer &sampleRays)
745	{
746	mStat.nodes = 1;
747	mBox.Initialize(); // initialise BSP tree bounding box
748
749	BoundedRayContainer *rays = new BoundedRayContainer();
750	PolygonContainer *polys = new PolygonContainer();
751
752	mGenerateViewCells = true;
753
754	// copy mesh instance polygons into one big polygon soup
755	mStat.polys = AddToPolygonSoup(objects, *polys);
756
757	RayContainer::const_iterator rit, rit_end = sampleRays.end();
758
759	//-- store rays
760	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
761	{
762	Ray ray = rit;
763	ray->SetId(-1); // reset id
764
765	float minT, maxT;
766	if (mBox.GetRaySegment(*ray, minT, maxT))
767	rays->push_back(new BoundedRay(ray, minT, maxT));
768	}
769
770	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
771	Construct(polys, rays);
772	}
773
774	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
775	{
776	BspTraversalStack tStack;
777
778	mRoot = new BspLeaf();
779
780	// constrruct root node geometry
781	BspNodeGeometry *geom = new BspNodeGeometry();
782	ConstructGeometry(mRoot, *geom);
783
784	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
785	ComputePvsSize(*rays), geom->GetArea(), geom);
786
787	tStack.push(tData);
788
789	mStat.Start();
790	cout << "Contructing bsp tree ... ";
791	long startTime = GetTime();
792	while (!tStack.empty())
793	{
794	tData = tStack.top();
795
796	tStack.pop();
797
798	// subdivide leaf node
799	BspNode *r = Subdivide(tStack, tData);
800
801	if (r == mRoot)
802	Debug << "BSP tree construction time spent at root: " << TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
803	}
804
805	cout << "finished\n";
806
807	mStat.Stop();
808	}
809
810	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
811	{
812	return
813	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
814	((int)data.mRays->size() <= mTermMinRays) \|\|
815	(data.mPvs <= mTermMinPvs) \|\|
816	(data.mArea <= mTermMinArea) \|\|
817	(data.mDepth >= mTermMaxDepth) \|\|
818	(data.GetAvgRayContribution() < mTermMaxRayContribution));
819	}
820
821	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
822	{
823	//-- terminate traversal
824	if (TerminationCriteriaMet(tData))
825	{
826	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
827
828	BspViewCell *viewCell;
829
830	// generate new view cell for each leaf
831	if (mGenerateViewCells)
832	viewCell = new BspViewCell();
833	else
834	// add view cell to leaf
835	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
836
837	leaf->SetViewCell(viewCell);
838	viewCell->mLeaves.push_back(leaf);
839
840	//-- add pvs
841	if (viewCell != mRootCell)
842	{
843	int conSamp = 0, sampCon = 0;
844	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
845
846	mStat.contributingSamples += conSamp;
847	mStat.sampleContributions += sampCon;
848	}
849
850	EvaluateLeafStats(tData);
851
852	//-- clean up
853
854	// discard polygons
855	CLEAR_CONTAINER(*tData.mPolygons);
856	// discard rays
857	CLEAR_CONTAINER(*tData.mRays);
858
859	DEL_PTR(tData.mPolygons);
860	DEL_PTR(tData.mRays);
861	DEL_PTR(tData.mGeometry);
862
863	return leaf;
864	}
865
866	//-- continue subdivision
867	PolygonContainer coincident;
868
869	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
870	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
871	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
872	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
873
874	// create new interior node and two leaf nodes
875	BspInterior *interior =
876	SubdivideNode(tData, tFrontData, tBackData, coincident);
877
878	#ifdef _DEBUG
879	// if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
880	// { for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
881	// Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
882	// Debug << endl;}
883	#endif
884
885	// extract view cells from coincident polygons according to plane normal
886	// only if front or back polygons are empty
887	if (!mGenerateViewCells)
888	{
889	ExtractViewCells(tFrontData,
890	tBackData,
891	coincident,
892	interior->mPlane);
893	}
894
895	// don't need coincident polygons anymory
896	CLEAR_CONTAINER(coincident);
897
898	// push the children on the stack
899	tStack.push(tFrontData);
900	tStack.push(tBackData);
901
902	// cleanup
903	DEL_PTR(tData.mNode);
904
905	DEL_PTR(tData.mPolygons);
906	DEL_PTR(tData.mRays);
907	DEL_PTR(tData.mGeometry);
908
909	return interior;
910	}
911
912	void BspTree::ExtractViewCells(BspTraversalData &frontData,
913	BspTraversalData &backData,
914	const PolygonContainer &coincident,
915	const Plane3 &splitPlane) const
916	{
917	// if not empty, tree is further subdivided => don't have to find view cell
918	bool foundFront = !frontData.mPolygons->empty();
919	bool foundBack = !frontData.mPolygons->empty();
920
921	PolygonContainer::const_iterator it =
922	coincident.begin(), it_end = coincident.end();
923
924	//-- find first view cells in front and back leafs
925	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
926	{
927	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
928	{
929	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
930	foundBack = true;
931	}
932	else
933	{
934	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
935	foundFront = true;
936	}
937	}
938	}
939
940	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
941	BspTraversalData &frontData,
942	BspTraversalData &backData,
943	PolygonContainer &coincident)
944	{
945	mStat.nodes += 2;
946
947	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
948
949	Debug << "*********************" << endl;
950	long startTime = GetTime();
951
952	// select subdivision plane
953	BspInterior *interior =
954	new BspInterior(SelectPlane(leaf, tData));
955	Debug << "time used for split plane selection: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
956	#ifdef _DEBUG
957	Debug << interior << endl;
958	#endif
959
960
961	Debug << "number of rays: " << (int)tData.mRays->size() << endl;
962	Debug << "number of polys: " << (int)tData.mPolygons->size() << endl;
963
964	startTime = GetTime();
965
966	// subdivide rays into front and back rays
967	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
968
969	Debug << "time used for rays splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
970
971	startTime = GetTime();
972	// subdivide polygons with plane
973	mStat.polySplits += SplitPolygons(interior->GetPlane(),
974	*tData.mPolygons,
975	*frontData.mPolygons,
976	*backData.mPolygons,
977	coincident);
978
979	Debug << "time used for polygon splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
980
981	// compute pvs
982	frontData.mPvs = ComputePvsSize(*frontData.mRays);
983	backData.mPvs = ComputePvsSize(*backData.mRays);
984
985	// split geometry and compute area
986	if (1)
987	{
988	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
989	*backData.mGeometry,
990	interior->mPlane,
991	mBox,
992	mEpsilon);
993
994
995	frontData.mArea = frontData.mGeometry->GetArea();
996	backData.mArea = backData.mGeometry->GetArea();
997	}
998
999	// compute accumulated ray length
1000	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
1001	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
1002
1003	//-- create front and back leaf
1004
1005	BspInterior *parent = leaf->GetParent();
1006
1007	// replace a link from node's parent
1008	if (!leaf->IsRoot())
1009	{
1010	parent->ReplaceChildLink(leaf, interior);
1011	interior->SetParent(parent);
1012	}
1013	else // new root
1014	{
1015	mRoot = interior;
1016	}
1017
1018	// and setup child links
1019	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1020
1021	frontData.mNode = interior->GetFront();
1022	backData.mNode = interior->GetBack();
1023
1024	//DEL_PTR(leaf);
1025	return interior;
1026	}
1027
1028	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1029	const int axis,
1030	vector<SortableEntry> &splitCandidates) const
1031	{
1032	splitCandidates.clear();
1033
1034	int requestedSize = 2 * (int)polys.size();
1035	// creates a sorted split candidates array
1036	splitCandidates.reserve(requestedSize);
1037
1038	PolygonContainer::const_iterator it, it_end = polys.end();
1039
1040	AxisAlignedBox3 box;
1041
1042	// insert all queries
1043	for(it = polys.begin(); it != it_end; ++ it)
1044	{
1045	box.Initialize();
1046	box.Include((it));
1047
1048	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1049	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1050	}
1051
1052	stable_sort(splitCandidates.begin(), splitCandidates.end());
1053	}
1054
1055
1056	float BspTree::BestCostRatio(const PolygonContainer &polys,
1057	const AxisAlignedBox3 &box,
1058	const int axis,
1059	float &position,
1060	int &objectsBack,
1061	int &objectsFront) const
1062	{
1063	vector<SortableEntry> splitCandidates;
1064
1065	SortSplitCandidates(polys, axis, splitCandidates);
1066
1067	// go through the lists, count the number of objects left and right
1068	// and evaluate the following cost funcion:
1069	// C = ct_div_ci + (ol + or)/queries
1070
1071	int objectsLeft = 0, objectsRight = (int)polys.size();
1072
1073	float minBox = box.Min(axis);
1074	float maxBox = box.Max(axis);
1075	float boxArea = box.SurfaceArea();
1076
1077	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1078	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1079
1080	float minSum = 1e20f;
1081	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1082
1083	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1084	{
1085	switch ((*ci).type)
1086	{
1087	case SortableEntry::POLY_MIN:
1088	++ objectsLeft;
1089	break;
1090	case SortableEntry::POLY_MAX:
1091	-- objectsRight;
1092	break;
1093	default:
1094	break;
1095	}
1096
1097	if ((ci).value > minBand && (ci).value < maxBand)
1098	{
1099	AxisAlignedBox3 lbox = box;
1100	AxisAlignedBox3 rbox = box;
1101	lbox.SetMax(axis, (*ci).value);
1102	rbox.SetMin(axis, (*ci).value);
1103
1104	const float sum = objectsLeft * lbox.SurfaceArea() +
1105	objectsRight * rbox.SurfaceArea();
1106
1107	if (sum < minSum)
1108	{
1109	minSum = sum;
1110	position = (*ci).value;
1111
1112	objectsBack = objectsLeft;
1113	objectsFront = objectsRight;
1114	}
1115	}
1116	}
1117
1118	const float oldCost = (float)polys.size();
1119	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1120	const float ratio = newCost / oldCost;
1121
1122
1123	#if 0
1124	Debug << "====================" << endl;
1125	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1126	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1127	#endif
1128	return ratio;
1129	}
1130
1131	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1132	const PolygonContainer &polys) const
1133	{
1134	AxisAlignedBox3 box;
1135	box.Initialize();
1136
1137	// create bounding box of region
1138	Polygon3::IncludeInBox(polys, box);
1139
1140	int objectsBack = 0, objectsFront = 0;
1141	int axis = 0;
1142	float costRatio = MAX_FLOAT;
1143	Vector3 position;
1144
1145	//-- area subdivision
1146	for (int i = 0; i < 3; ++ i)
1147	{
1148	float p = 0;
1149	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1150
1151	if (r < costRatio)
1152	{
1153	costRatio = r;
1154	axis = i;
1155	position = p;
1156	}
1157	}
1158
1159	if (costRatio >= mMaxCostRatio)
1160	return false;
1161
1162	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1163	plane = Plane3(norm, position);
1164
1165	return true;
1166	}
1167
1168	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1169	{
1170	if (data.mPolygons->empty() && data.mRays->empty())
1171	{
1172	Debug << "Warning: No autopartition polygon candidate available\n";
1173
1174	// return axis aligned split
1175	AxisAlignedBox3 box;
1176	box.Initialize();
1177
1178	// create bounding box of region
1179	Polygon3::IncludeInBox(*data.mPolygons, box);
1180
1181	const int axis = box.Size().DrivingAxis();
1182	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1183
1184	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1185	return Plane3(norm, position);
1186	}
1187
1188	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1189	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1190	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1191	((mTermMinObjectsForAxisAligned < 0) \|\|
1192	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1193	{
1194	Plane3 plane;
1195	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1196	return plane;
1197	}
1198
1199	// simplest strategy: just take next polygon
1200	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1201	{
1202	if (!data.mPolygons->empty())
1203	{
1204	Polygon3 *nextPoly =
1205	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1206	return nextPoly->GetSupportingPlane();
1207	}
1208	else
1209	{
1210	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1211	BoundedRay bRay = (data.mRays)[candidateIdx];
1212
1213	Ray *ray = bRay->mRay;
1214
1215	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1216	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1217
1218	const Vector3 pt = (maxPt + minPt) * 0.5;
1219
1220	const Vector3 normal = ray->GetDir();
1221
1222	return Plane3(normal, pt);
1223	}
1224
1225	return Plane3();
1226	}
1227
1228	// use heuristics to find appropriate plane
1229	return SelectPlaneHeuristics(leaf, data);
1230	}
1231
1232
1233	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1234	{
1235	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1236	BoundedRay *bRay = rays[candidateIdx];
1237	Ray *ray = bRay->mRay;
1238
1239	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1240	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1241
1242	const Vector3 pt = (maxPt + minPt) * 0.5;
1243
1244	const Vector3 normal = ray->GetDir();
1245
1246	return Plane3(normal, pt);
1247	}
1248
1249	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1250	{
1251	Vector3 pt[3];
1252	int idx[3];
1253	int cmaxT = 0;
1254	int cminT = 0;
1255	bool chooseMin = false;
1256
1257	for (int j = 0; j < 3; j ++)
1258	{
1259	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1260
1261	if (idx[j] >= (int)rays.size())
1262	{
1263	idx[j] -= (int)rays.size();
1264	chooseMin = (cminT < 2);
1265	}
1266	else
1267	chooseMin = (cmaxT < 2);
1268
1269	BoundedRay *bRay = rays[idx[j]];
1270	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1271	bRay->mRay->Extrap(bRay->mMaxT);
1272	}
1273
1274	return Plane3(pt[0], pt[1], pt[2]);
1275	}
1276
1277	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1278	{
1279	Vector3 pt[3];
1280
1281	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1282	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1283
1284	// check if rays different
1285	if (idx1 == idx2)
1286	idx2 = (idx2 + 1) % (int)rays.size();
1287
1288	const BoundedRay *ray1 = rays[idx1];
1289	const BoundedRay *ray2 = rays[idx2];
1290
1291	// normal vector of the plane parallel to both lines
1292	const Vector3 norm =
1293	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1294
1295	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1296	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1297
1298	// vector from line 1 to line 2
1299	const Vector3 vd = orig1 - orig2;
1300
1301	// project vector on normal to get distance
1302	const float dist = DotProd(vd, norm);
1303
1304	// point on plane lies halfway between the two planes
1305	const Vector3 planePt = orig1 + norm * dist * 0.5;
1306
1307	return Plane3(norm, planePt);
1308	}
1309
1310
1311	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1312	{
1313	float lowestCost = MAX_FLOAT;
1314	Plane3 bestPlane;
1315	// intermediate plane
1316	Plane3 plane;
1317
1318	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1319	int maxIdx = (int)data.mPolygons->size();
1320
1321	for (int i = 0; i < limit; ++ i)
1322	{
1323	// assure that no index is taken twice
1324	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1325	//Debug << "current Idx: " << maxIdx << " cand idx " << candidateIdx << endl;
1326
1327	Polygon3 poly = (data.mPolygons)[candidateIdx];
1328
1329	// swap candidate to the end to avoid testing same plane
1330	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1331
1332	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1333
1334	// evaluate current candidate
1335	const float candidateCost =
1336	SplitPlaneCost(poly->GetSupportingPlane(), data);
1337
1338	if (candidateCost < lowestCost)
1339	{
1340	bestPlane = poly->GetSupportingPlane();
1341	lowestCost = candidateCost;
1342	}
1343	}
1344
1345	//-- choose candidate planes extracted from rays
1346	for (int i = 0; i < mMaxRayCandidates; ++ i)
1347	{
1348	plane = ChooseCandidatePlane3(*data.mRays);
1349	const float candidateCost = SplitPlaneCost(plane, data);
1350
1351	if (candidateCost < lowestCost)
1352	{
1353	bestPlane = plane;
1354	lowestCost = candidateCost;
1355	}
1356	}
1357
1358	#ifdef _DEBUG
1359	Debug << "plane lowest cost: " << lowestCost << endl;
1360	#endif
1361
1362	return bestPlane;
1363	}
1364
1365
1366	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1367	const PolygonContainer &polys) const
1368	{
1369	float val = 0;
1370
1371	float sumBalancedPolys = 0;
1372	float sumSplits = 0;
1373	float sumPolyArea = 0;
1374	float sumBalancedViewCells = 0;
1375	float sumBlockedRays = 0;
1376	float totalBlockedRays = 0;
1377	//float totalArea = 0;
1378	int totalViewCells = 0;
1379
1380	// need three unique ids for each type of view cell
1381	// for balanced view cells criterium
1382	ViewCell::NewMail();
1383	const int backId = ViewCell::sMailId;
1384	ViewCell::NewMail();
1385	const int frontId = ViewCell::sMailId;
1386	ViewCell::NewMail();
1387	const int frontAndBackId = ViewCell::sMailId;
1388
1389	bool useRand;;
1390	int limit;
1391
1392	// choose test polyongs randomly if over threshold
1393	if ((int)polys.size() > mMaxTests)
1394	{
1395	useRand = true;
1396	limit = mMaxTests;
1397	}
1398	else
1399	{
1400	useRand = false;
1401	limit = (int)polys.size();
1402	}
1403
1404	for (int i = 0; i < limit; ++ i)
1405	{
1406	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1407
1408	Polygon3 *poly = polys[testIdx];
1409
1410	const int classification =
1411	poly->ClassifyPlane(candidatePlane, mEpsilon);
1412
1413	if (mSplitPlaneStrategy & BALANCED_POLYS)
1414	sumBalancedPolys += sBalancedPolysTable[classification];
1415
1416	if (mSplitPlaneStrategy & LEAST_SPLITS)
1417	sumSplits += sLeastPolySplitsTable[classification];
1418
1419	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1420	{
1421	if (classification == Polygon3::COINCIDENT)
1422	sumPolyArea += poly->GetArea();
1423	//totalArea += area;
1424	}
1425
1426	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1427	{
1428	const float blockedRays = (float)poly->mPiercingRays.size();
1429
1430	if (classification == Polygon3::COINCIDENT)
1431	sumBlockedRays += blockedRays;
1432
1433	totalBlockedRays += blockedRays;
1434	}
1435
1436	// assign view cells to back or front according to classificaion
1437	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1438	{
1439	MeshInstance *viewCell = poly->mParent;
1440
1441	// assure that we only count a view cell
1442	// once for the front and once for the back side of the plane
1443	if (classification == Polygon3::FRONT_SIDE)
1444	{
1445	if ((viewCell->mMailbox != frontId) &&
1446	(viewCell->mMailbox != frontAndBackId))
1447	{
1448	sumBalancedViewCells += 1.0;
1449
1450	if (viewCell->mMailbox != backId)
1451	viewCell->mMailbox = frontId;
1452	else
1453	viewCell->mMailbox = frontAndBackId;
1454
1455	++ totalViewCells;
1456	}
1457	}
1458	else if (classification == Polygon3::BACK_SIDE)
1459	{
1460	if ((viewCell->mMailbox != backId) &&
1461	(viewCell->mMailbox != frontAndBackId))
1462	{
1463	sumBalancedViewCells -= 1.0;
1464
1465	if (viewCell->mMailbox != frontId)
1466	viewCell->mMailbox = backId;
1467	else
1468	viewCell->mMailbox = frontAndBackId;
1469
1470	++ totalViewCells;
1471	}
1472	}
1473	}
1474	}
1475
1476	const float polysSize = (float)polys.size() + Limits::Small;
1477
1478	// all values should be approx. between 0 and 1 so they can be combined
1479	// and scaled with the factors according to their importance
1480	if (mSplitPlaneStrategy & BALANCED_POLYS)
1481	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1482
1483	if (mSplitPlaneStrategy & LEAST_SPLITS)
1484	val += mLeastSplitsFactor * sumSplits / polysSize;
1485
1486	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1487	// HACK: polys.size should be total area so scaling is between 0 and 1
1488	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1489
1490	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1491	if (totalBlockedRays != 0)
1492	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1493
1494	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1495	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1496	((float)totalViewCells + Limits::Small);
1497
1498	return val;
1499	}
1500
1501
1502	inline void BspTree::GenerateUniqueIdsForPvs()
1503	{
1504	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1505	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1506	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1507	}
1508
1509	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1510	const BoundedRayContainer &rays,
1511	const int pvs,
1512	const float area,
1513	const BspNodeGeometry &cell) const
1514	{
1515	float val = 0;
1516
1517	float sumBalancedRays = 0;
1518	float sumRaySplits = 0;
1519
1520	int frontPvs = 0;
1521	int backPvs = 0;
1522
1523	// probability that view point lies in child
1524	float pOverall = 0;
1525	float pFront = 0;
1526	float pBack = 0;
1527
1528	const bool pvsUseLen = false;
1529
1530	if (mSplitPlaneStrategy & PVS)
1531	{
1532	// create unique ids for pvs heuristics
1533	GenerateUniqueIdsForPvs();
1534
1535	if (mPvsUseArea) // use front and back cell areas to approximate volume
1536	{
1537	// construct child geometry with regard to the candidate split plane
1538	BspNodeGeometry frontCell;
1539	BspNodeGeometry backCell;
1540
1541	cell.SplitGeometry(frontCell,
1542	backCell,
1543	candidatePlane,
1544	mBox,
1545	mEpsilon);
1546
1547	pFront = frontCell.GetArea();
1548	pBack = backCell.GetArea();
1549
1550	pOverall = area;
1551	}
1552	}
1553
1554	bool useRand;;
1555	int limit;
1556
1557	// choose test polyongs randomly if over threshold
1558	if ((int)rays.size() > mMaxTests)
1559	{
1560	useRand = true;
1561	limit = mMaxTests;
1562	}
1563	else
1564	{
1565	useRand = false;
1566	limit = (int)rays.size();
1567	}
1568
1569	for (int i = 0; i < limit; ++ i)
1570	{
1571	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1572
1573	BoundedRay *bRay = rays[testIdx];
1574
1575	Ray *ray = bRay->mRay;
1576	const float minT = bRay->mMinT;
1577	const float maxT = bRay->mMaxT;
1578
1579	Vector3 entP, extP;
1580
1581	const int cf =
1582	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1583
1584	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1585	{
1586	sumBalancedRays += sBalancedRaysTable[cf];
1587	}
1588
1589	if (mSplitPlaneStrategy & BALANCED_RAYS)
1590	{
1591	sumRaySplits += sLeastRaySplitsTable[cf];
1592	}
1593
1594	if (mSplitPlaneStrategy & PVS)
1595	{
1596	// in case the ray intersects an object
1597	// assure that we only count the object
1598	// once for the front and once for the back side of the plane
1599
1600	// add the termination object
1601	if (!ray->intersections.empty())
1602	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1603
1604	// add the source object
1605	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1606
1607	if (mPvsUseArea)
1608	{
1609	float len = 1;
1610
1611	if (pvsUseLen)
1612	len = SqrDistance(entP, extP);
1613
1614	// use length of rays to approximate volume
1615	if (Ray::BACK && Ray::COINCIDENT)
1616	pBack += len;
1617	if (Ray::FRONT && Ray::COINCIDENT)
1618	pFront += len;
1619	if (Ray::FRONT_BACK \|\| Ray::BACK_FRONT)
1620	{
1621	if (pvsUseLen)
1622	{
1623	const Vector3 extp = ray->Extrap(maxT);
1624	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1625
1626	const float newT = t * maxT;
1627	const float newLen = SqrDistance(ray->Extrap(newT), extp);
1628
1629	if (Ray::FRONT_BACK)
1630	{
1631	pFront += len - newLen;
1632	pBack += newLen;
1633	}
1634	else
1635	{
1636	pBack += len - newLen;
1637	pFront += newLen;
1638	}
1639	}
1640	else
1641	{
1642	++ pFront;
1643	++ pBack;
1644	}
1645	}
1646	}
1647	}
1648	}
1649
1650	const float raysSize = (float)rays.size() + Limits::Small;
1651
1652	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1653	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1654
1655	if (mSplitPlaneStrategy & BALANCED_RAYS)
1656	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1657
1658	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1659
1660	if (mSplitPlaneStrategy & PVS)
1661	{
1662	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1663
1664	// give penalty to unbalanced split
1665	if (0)
1666	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1667	(pFront < (pBack * 0.2 + Limits::Small)))
1668	val += 0.5;
1669	}
1670
1671
1672	#ifdef _DEBUG
1673	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1674	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1675	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1676	#endif
1677
1678	return val;
1679	}
1680
1681	void BspTree::AddObjToPvs(Intersectable *obj,
1682	const int cf,
1683	int &frontPvs,
1684	int &backPvs) const
1685	{
1686	if (!obj)
1687	return;
1688	// TODO: does this really belong to no pvs?
1689	//if (cf == Ray::COINCIDENT) return;
1690
1691	// object belongs to both PVS
1692	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1693	(cf == Ray::BACK_FRONT) \|\|
1694	(cf == Ray::COINCIDENT);
1695
1696	if ((cf == Ray::FRONT) \|\| bothSides)
1697	{
1698	if ((obj->mMailbox != sFrontId) &&
1699	(obj->mMailbox != sFrontAndBackId))
1700	{
1701	++ frontPvs;
1702
1703	if (obj->mMailbox == sBackId)
1704	obj->mMailbox = sFrontAndBackId;
1705	else
1706	obj->mMailbox = sFrontId;
1707	}
1708	}
1709
1710	if ((cf == Ray::BACK) \|\| bothSides)
1711	{
1712	if ((obj->mMailbox != sBackId) &&
1713	(obj->mMailbox != sFrontAndBackId))
1714	{
1715	++ backPvs;
1716
1717	if (obj->mMailbox == sFrontId)
1718	obj->mMailbox = sFrontAndBackId;
1719	else
1720	obj->mMailbox = sBackId;
1721	}
1722	}
1723	}
1724
1725	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1726	BspTraversalData &data) const
1727	{
1728	float val = 0;
1729
1730	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1731	{
1732	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1733	// we put a penalty on the dot product between the "tiny" vertical axis
1734	// and the split plane axis
1735	val += mVerticalSplitsFactor *
1736	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1737	}
1738
1739	// the following criteria loop over all polygons to find the cost value
1740	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1741	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1742	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1743	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1744	(mSplitPlaneStrategy & BLOCKED_RAYS))
1745	{
1746	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1747	}
1748
1749	// the following criteria loop over all rays to find the cost value
1750	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1751	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1752	(mSplitPlaneStrategy & PVS))
1753	{
1754	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1755	data.mArea, *data.mGeometry);
1756	}
1757
1758	// return linear combination of the sums
1759	return val;
1760	}
1761
1762	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1763	{
1764	stack<BspNode *> nodeStack;
1765	nodeStack.push(mRoot);
1766
1767	while (!nodeStack.empty())
1768	{
1769	BspNode *node = nodeStack.top();
1770
1771	nodeStack.pop();
1772
1773	if (node->IsLeaf())
1774	{
1775	BspLeaf leaf = (BspLeaf )node;
1776	leaves.push_back(leaf);
1777	}
1778	else
1779	{
1780	BspInterior interior = dynamic_cast<BspInterior >(node);
1781
1782	nodeStack.push(interior->GetBack());
1783	nodeStack.push(interior->GetFront());
1784	}
1785	}
1786	}
1787
1788
1789	AxisAlignedBox3 BspTree::GetBoundingBox() const
1790	{
1791	return mBox;
1792	}
1793
1794
1795	BspNode *BspTree::GetRoot() const
1796	{
1797	return mRoot;
1798	}
1799
1800	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1801	{
1802	// the node became a leaf -> evaluate stats for leafs
1803	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1804
1805	// store maximal and minimal depth
1806	if (data.mDepth > mStat.maxDepth)
1807	mStat.maxDepth = data.mDepth;
1808
1809	if (data.mDepth < mStat.minDepth)
1810	mStat.minDepth = data.mDepth;
1811
1812	// accumulate depth to compute average depth
1813	mStat.accumDepth += data.mDepth;
1814	// accumulate rays to compute rays / leaf
1815	mStat.accumRays += (int)data.mRays->size();
1816
1817	if (data.mDepth >= mTermMaxDepth)
1818	++ mStat.maxDepthNodes;
1819
1820	if (data.mPvs < mTermMinPvs)
1821	++ mStat.minPvsNodes;
1822
1823	if ((int)data.mRays->size() < mTermMinRays)
1824	++ mStat.minRaysNodes;
1825
1826	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1827	++ mStat.maxRayContribNodes;
1828
1829	if (data.mGeometry->GetArea() <= mTermMinArea)
1830	++ mStat.minAreaNodes;
1831
1832	#ifdef _DEBUG
1833	Debug << "BSP stats: "
1834	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1835	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1836	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1837	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1838	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1839	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1840	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1841	#endif
1842	}
1843
1844	int
1845	BspTree::_CastRay(Ray &ray)
1846	{
1847	int hits = 0;
1848
1849	stack<BspRayTraversalData> tStack;
1850
1851	float maxt, mint;
1852
1853	if (!mBox.GetRaySegment(ray, mint, maxt))
1854	return 0;
1855
1856	Intersectable::NewMail();
1857
1858	Vector3 entp = ray.Extrap(mint);
1859	Vector3 extp = ray.Extrap(maxt);
1860
1861	BspNode *node = mRoot;
1862	BspNode *farChild = NULL;
1863
1864	while (1)
1865	{
1866	if (!node->IsLeaf())
1867	{
1868	BspInterior in = dynamic_cast<BspInterior >(node);
1869
1870	Plane3 splitPlane = in->GetPlane();
1871	const int entSide = splitPlane.Side(entp);
1872	const int extSide = splitPlane.Side(extp);
1873
1874	if (entSide < 0)
1875	{
1876	node = in->GetBack();
1877
1878	if(extSide <= 0) // plane does not split ray => no far child
1879	continue;
1880
1881	farChild = in->GetFront(); // plane splits ray
1882
1883	} else if (entSide > 0)
1884	{
1885	node = in->GetFront();
1886
1887	if (extSide >= 0) // plane does not split ray => no far child
1888	continue;
1889
1890	farChild = in->GetBack(); // plane splits ray
1891	}
1892	else // ray and plane are coincident
1893	{
1894	// WHAT TO DO IN THIS CASE ?
1895	//break;
1896	node = in->GetFront();
1897	continue;
1898	}
1899
1900	// push data for far child
1901	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1902
1903	// find intersection of ray segment with plane
1904	float t;
1905	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
1906	maxt *= t;
1907
1908	} else // reached leaf => intersection with view cell
1909	{
1910	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1911
1912	if (!leaf->mViewCell->Mailed())
1913	{
1914	// ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1915	leaf->mViewCell->Mail();
1916	++ hits;
1917	}
1918
1919	//-- fetch the next far child from the stack
1920	if (tStack.empty())
1921	break;
1922
1923	entp = extp;
1924	mint = maxt; // NOTE: need this?
1925
1926	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1927	break;
1928
1929	BspRayTraversalData &s = tStack.top();
1930
1931	node = s.mNode;
1932	extp = s.mExitPoint;
1933	maxt = s.mMaxT;
1934
1935	tStack.pop();
1936	}
1937	}
1938
1939	return hits;
1940	}
1941
1942
1943	int BspTree::CastLineSegment(const Vector3 &origin,
1944	const Vector3 &termination,
1945	vector<ViewCell *> &viewcells)
1946	{
1947	int hits = 0;
1948	stack<BspRayTraversalData> tStack;
1949
1950	float mint = 0.0f, maxt = 1.0f;
1951
1952	Intersectable::NewMail();
1953
1954	Vector3 entp = origin;
1955	Vector3 extp = termination;
1956
1957	BspNode *node = mRoot;
1958	BspNode *farChild = NULL;
1959
1960	while (1)
1961	{
1962	if (!node->IsLeaf())
1963	{
1964	BspInterior in = dynamic_cast<BspInterior >(node);
1965
1966	Plane3 splitPlane = in->GetPlane();
1967
1968	const int entSide = splitPlane.Side(entp);
1969	const int extSide = splitPlane.Side(extp);
1970
1971	if (entSide < 0)
1972	{
1973	node = in->GetBack();
1974
1975	if(extSide <= 0) // plane does not split ray => no far child
1976	continue;
1977
1978	farChild = in->GetFront(); // plane splits ray
1979
1980	}
1981	else if (entSide > 0)
1982	{
1983	node = in->GetFront();
1984
1985	if (extSide >= 0) // plane does not split ray => no far child
1986	continue;
1987
1988	farChild = in->GetBack(); // plane splits ray
1989	}
1990	else // ray and plane are coincident
1991	{
1992	// WHAT TO DO IN THIS CASE ?
1993	//break;
1994	node = in->GetFront();
1995	continue;
1996	}
1997
1998	// push data for far child
1999	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2000
2001	// find intersection of ray segment with plane
2002	float t;
2003	extp = splitPlane.FindIntersection(origin, extp, &t);
2004	maxt *= t;
2005	}
2006	else
2007	{
2008	// reached leaf => intersection with view cell
2009	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2010
2011	if (!leaf->mViewCell->Mailed())
2012	{
2013	viewcells.push_back(leaf->mViewCell);
2014	leaf->mViewCell->Mail();
2015	hits++;
2016	}
2017
2018	//-- fetch the next far child from the stack
2019	if (tStack.empty())
2020	break;
2021
2022	entp = extp;
2023	mint = maxt; // NOTE: need this?
2024
2025	BspRayTraversalData &s = tStack.top();
2026
2027	node = s.mNode;
2028	extp = s.mExitPoint;
2029	maxt = s.mMaxT;
2030
2031	tStack.pop();
2032	}
2033	}
2034	return hits;
2035	}
2036
2037	bool BspTree::Export(const string filename)
2038	{
2039	Exporter *exporter = Exporter::GetExporter(filename);
2040
2041	if (exporter)
2042	{
2043	exporter->ExportBspTree(*this);
2044	return true;
2045	}
2046
2047	return false;
2048	}
2049
2050	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2051	{
2052	stack<BspNode *> nodeStack;
2053	nodeStack.push(mRoot);
2054
2055	ViewCell::NewMail();
2056
2057	while (!nodeStack.empty())
2058	{
2059	BspNode *node = nodeStack.top();
2060	nodeStack.pop();
2061
2062	if (node->IsLeaf())
2063	{
2064	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2065
2066	if (!viewCell->Mailed())
2067	{
2068	viewCell->Mail();
2069	viewCells.push_back(viewCell);
2070	}
2071	}
2072	else
2073	{
2074	BspInterior interior = dynamic_cast<BspInterior >(node);
2075
2076	nodeStack.push(interior->GetFront());
2077	nodeStack.push(interior->GetBack());
2078	}
2079	}
2080	}
2081
2082
2083	BspTreeStatistics &BspTree::GetStat()
2084	{
2085	return mStat;
2086	}
2087
2088
2089	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2090	{
2091	float len = 0;
2092
2093	BoundedRayContainer::const_iterator it, it_end = rays.end();
2094
2095	for (it = rays.begin(); it != it_end; ++ it)
2096	{
2097	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2098	(it)->mRay->Extrap((it)->mMaxT));
2099	}
2100
2101	return len;
2102	}
2103
2104
2105	int BspTree::SplitRays(const Plane3 &plane,
2106	BoundedRayContainer &rays,
2107	BoundedRayContainer &frontRays,
2108	BoundedRayContainer &backRays)
2109	{
2110	int splits = 0;
2111
2112	while (!rays.empty())
2113	{
2114	BoundedRay *bRay = rays.back();
2115	Ray *ray = bRay->mRay;
2116	float minT = bRay->mMinT;
2117	float maxT = bRay->mMaxT;
2118
2119	rays.pop_back();
2120
2121	Vector3 entP, extP;
2122
2123	const int cf =
2124	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2125
2126	// set id to ray classification
2127	ray->SetId(cf);
2128
2129	switch (cf)
2130	{
2131	case Ray::COINCIDENT: // TODO: should really discard ray?
2132	frontRays.push_back(bRay);
2133	//DEL_PTR(bRay);
2134	break;
2135	case Ray::BACK:
2136	backRays.push_back(bRay);
2137	break;
2138	case Ray::FRONT:
2139	frontRays.push_back(bRay);
2140	break;
2141	case Ray::FRONT_BACK:
2142	{
2143	// find intersection of ray segment with plane
2144	const float t = plane.FindT(ray->GetLoc(), extP);
2145
2146	const float newT = t * maxT;
2147
2148	frontRays.push_back(new BoundedRay(ray, minT, newT));
2149	backRays.push_back(new BoundedRay(ray, newT, maxT));
2150
2151	DEL_PTR(bRay);
2152	}
2153	break;
2154	case Ray::BACK_FRONT:
2155	{
2156	// find intersection of ray segment with plane
2157	const float t = plane.FindT(ray->GetLoc(), extP);
2158	const float newT = t * bRay->mMaxT;
2159
2160	backRays.push_back(new BoundedRay(ray, minT, newT));
2161	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2162
2163	DEL_PTR(bRay);
2164
2165	++ splits;
2166	}
2167	break;
2168	default:
2169	Debug << "Should not come here 4" << endl;
2170	break;
2171	}
2172	}
2173
2174	return splits;
2175	}
2176
2177	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2178	{
2179	BspNode *lastNode;
2180	do
2181	{
2182	lastNode = n;
2183
2184	// want to get planes defining geometry of this node => don't take
2185	// split plane of node itself
2186	n = n->GetParent();
2187
2188	if (n)
2189	{
2190	BspInterior interior = dynamic_cast<BspInterior >(n);
2191	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2192
2193	if (interior->GetFront() != lastNode)
2194	halfSpace.ReverseOrientation();
2195
2196	halfSpaces.push_back(halfSpace);
2197	}
2198	}
2199	while (n);
2200	}
2201
2202	void BspTree::ConstructGeometry(BspViewCell *vc, BspNodeGeometry &geom) const
2203	{
2204	vector<BspLeaf *> leaves = vc->mLeaves;
2205
2206	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2207
2208	for (it = leaves.begin(); it != it_end; ++ it)
2209	ConstructGeometry(*it, geom);
2210	}
2211
2212
2213	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2214	{
2215	vector<Plane3> halfSpaces;
2216	ExtractHalfSpaces(n, halfSpaces);
2217
2218	PolygonContainer candidates;
2219
2220	// bounded planes are added to the polygons (reverse polygons
2221	// as they have to be outfacing
2222	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2223	{
2224	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2225
2226	if (p->Valid(mEpsilon))
2227	{
2228	candidates.push_back(p->CreateReversePolygon());
2229	DEL_PTR(p);
2230	}
2231	}
2232
2233	// add faces of bounding box (also could be faces of the cell)
2234	for (int i = 0; i < 6; ++ i)
2235	{
2236	VertexContainer vertices;
2237
2238	for (int j = 0; j < 4; ++ j)
2239	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2240
2241	candidates.push_back(new Polygon3(vertices));
2242	}
2243
2244	for (int i = 0; i < (int)candidates.size(); ++ i)
2245	{
2246	// polygon is split by all other planes
2247	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2248	{
2249	if (i == j) // polygon and plane are coincident
2250	continue;
2251
2252	VertexContainer splitPts;
2253	Polygon3 frontPoly, backPoly;
2254
2255	const int cf = candidates[i]->
2256	ClassifyPlane(halfSpaces[j], mEpsilon);
2257
2258	switch (cf)
2259	{
2260	case Polygon3::SPLIT:
2261	frontPoly = new Polygon3();
2262	backPoly = new Polygon3();
2263
2264	candidates[i]->Split(halfSpaces[j],
2265	*frontPoly,
2266	*backPoly,
2267	mEpsilon);
2268
2269	DEL_PTR(candidates[i]);
2270
2271	if (frontPoly->Valid(mEpsilon))
2272	candidates[i] = frontPoly;
2273	else
2274	DEL_PTR(frontPoly);
2275
2276	DEL_PTR(backPoly);
2277	break;
2278	case Polygon3::BACK_SIDE:
2279	DEL_PTR(candidates[i]);
2280	break;
2281	// just take polygon as it is
2282	case Polygon3::FRONT_SIDE:
2283	case Polygon3::COINCIDENT:
2284	default:
2285	break;
2286	}
2287	}
2288
2289	if (candidates[i])
2290	geom.mPolys.push_back(candidates[i]);
2291	}
2292	}
2293
2294
2295	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2296	const bool onlyUnmailed) const
2297	{
2298	BspNodeGeometry geom;
2299	ConstructGeometry(n, geom);
2300
2301	stack<BspNode *> nodeStack;
2302	nodeStack.push(mRoot);
2303
2304	// planes needed to verify that we found neighbor leaf.
2305	vector<Plane3> halfSpaces;
2306	ExtractHalfSpaces(n, halfSpaces);
2307
2308	while (!nodeStack.empty())
2309	{
2310	BspNode *node = nodeStack.top();
2311	nodeStack.pop();
2312
2313	if (node->IsLeaf())
2314	{
2315	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2316	{
2317	// test all planes of current node if neighbour
2318	// candidate really is neighbour
2319	BspNodeGeometry candidateGeom;
2320	ConstructGeometry(node, candidateGeom);
2321
2322	bool isAdjacent = true;
2323	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2324	{
2325	const int cf =
2326	Polygon3::ClassifyPlane(candidateGeom.mPolys,
2327	halfSpaces[i],
2328	mEpsilon);
2329
2330	if (cf == Polygon3::BACK_SIDE)
2331	isAdjacent = false;
2332	}
2333
2334	if (isAdjacent)
2335	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2336	}
2337	}
2338	else
2339	{
2340	BspInterior interior = dynamic_cast<BspInterior >(node);
2341
2342	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2343	interior->mPlane,
2344	mEpsilon);
2345
2346	if (cf == Polygon3::FRONT_SIDE)
2347	nodeStack.push(interior->GetFront());
2348	else
2349	if (cf == Polygon3::BACK_SIDE)
2350	nodeStack.push(interior->GetBack());
2351	else
2352	{
2353	// random decision
2354	nodeStack.push(interior->GetBack());
2355	nodeStack.push(interior->GetFront());
2356	}
2357	}
2358	}
2359
2360	return (int)neighbors.size();
2361	}
2362
2363
2364	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2365	{
2366	stack<BspNode *> nodeStack;
2367	nodeStack.push(mRoot);
2368
2369	int mask = rand();
2370
2371	while (!nodeStack.empty())
2372	{
2373	BspNode *node = nodeStack.top();
2374	nodeStack.pop();
2375
2376	if (node->IsLeaf())
2377	{
2378	return dynamic_cast<BspLeaf *>(node);
2379	}
2380	else
2381	{
2382	BspInterior interior = dynamic_cast<BspInterior >(node);
2383	BspNode *next;
2384
2385	BspNodeGeometry geom;
2386	// todo: not very efficient: constructs full cell everytime
2387	ConstructGeometry(interior, geom);
2388
2389	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2390	halfspace,
2391	mEpsilon);
2392
2393	if (cf == Polygon3::BACK_SIDE)
2394	next = interior->GetFront();
2395	else
2396	if (cf == Polygon3::FRONT_SIDE)
2397	next = interior->GetFront();
2398	else
2399	{
2400	// random decision
2401	if (mask & 1)
2402	next = interior->GetBack();
2403	else
2404	next = interior->GetFront();
2405	mask = mask >> 1;
2406	}
2407
2408	nodeStack.push(next);
2409	}
2410	}
2411
2412	return NULL;
2413	}
2414
2415	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2416	{
2417	stack<BspNode *> nodeStack;
2418
2419	nodeStack.push(mRoot);
2420
2421	int mask = rand();
2422
2423	while (!nodeStack.empty())
2424	{
2425	BspNode *node = nodeStack.top();
2426	nodeStack.pop();
2427
2428	if (node->IsLeaf())
2429	{
2430	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2431	return dynamic_cast<BspLeaf *>(node);
2432	}
2433	else
2434	{
2435	BspInterior interior = dynamic_cast<BspInterior >(node);
2436
2437	// random decision
2438	if (mask & 1)
2439	nodeStack.push(interior->GetBack());
2440	else
2441	nodeStack.push(interior->GetFront());
2442
2443	mask = mask >> 1;
2444	}
2445	}
2446
2447	return NULL;
2448	}
2449
2450	void BspTree::AddToPvs(BspLeaf *leaf,
2451	const BoundedRayContainer &rays,
2452	int &sampleContributions,
2453	int &contributingSamples)
2454	{
2455	sampleContributions = 0;
2456	contributingSamples = 0;
2457
2458	BoundedRayContainer::const_iterator it, it_end = rays.end();
2459
2460	ViewCell *vc = leaf->GetViewCell();
2461
2462	// add contributions from samples to the PVS
2463	for (it = rays.begin(); it != it_end; ++ it)
2464	{
2465	int contribution = 0;
2466	Ray ray = (it)->mRay;
2467	float relContribution;
2468	if (!ray->intersections.empty())
2469	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject, relContribution);
2470
2471	if (ray->sourceObject.mObject)
2472	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject, relContribution);
2473
2474	if (contribution)
2475	{
2476	sampleContributions += contribution;
2477	++ contributingSamples;
2478	}
2479
2480	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2481	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2482	}
2483	}
2484
2485	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2486	{
2487	int pvsSize = 0;
2488
2489	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2490
2491	Intersectable::NewMail();
2492
2493	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2494	{
2495	Ray ray = (rit)->mRay;
2496
2497	if (!ray->intersections.empty())
2498	{
2499	if (!ray->intersections[0].mObject->Mailed())
2500	{
2501	ray->intersections[0].mObject->Mail();
2502	++ pvsSize;
2503	}
2504	}
2505	if (ray->sourceObject.mObject)
2506	{
2507	if (!ray->sourceObject.mObject->Mailed())
2508	{
2509	ray->sourceObject.mObject->Mail();
2510	++ pvsSize;
2511	}
2512	}
2513	}
2514
2515	return pvsSize;
2516	}
2517
2518	float BspTree::GetEpsilon() const
2519	{
2520	return mEpsilon;
2521	}
2522
2523
2524	/*************************************************************/
2525	/* BspNodeGeometry Implementation */
2526	/*************************************************************/
2527
2528
2529	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2530	{
2531	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2532	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2533	{
2534	Polygon3 poly = it;
2535	mPolys.push_back(new Polygon3(*poly));
2536	}
2537	}
2538
2539	BspNodeGeometry::~BspNodeGeometry()
2540	{
2541	CLEAR_CONTAINER(mPolys);
2542	}
2543
2544
2545	float BspNodeGeometry::GetArea() const
2546	{
2547	return Polygon3::GetArea(mPolys);
2548	}
2549
2550
2551	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2552	{
2553	PolygonContainer::const_iterator it, it_end = mPolys.end();
2554
2555	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2556	{
2557	(*it)->AddToMesh(mesh);
2558	}
2559	}
2560
2561
2562	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2563	BspNodeGeometry &back,
2564	const Plane3 &splitPlane,
2565	const AxisAlignedBox3 &box,
2566	const float epsilon) const
2567	{
2568	// get cross section of new polygon
2569	Polygon3 *planePoly = box.CrossSection(splitPlane);
2570
2571	// split polygon with all other polygons
2572	planePoly = SplitPolygon(planePoly, epsilon);
2573
2574	//-- new polygon splits all other polygons
2575	for (int i = 0; i < (int)mPolys.size(); ++ i)
2576	{
2577	/// don't use epsilon here to get exact split planes
2578	const int cf =
2579	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2580
2581	switch (cf)
2582	{
2583	case Polygon3::SPLIT:
2584	{
2585	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2586
2587	Polygon3 *frontPoly = new Polygon3();
2588	Polygon3 *backPoly = new Polygon3();
2589
2590	poly->Split(splitPlane,
2591	*frontPoly,
2592	*backPoly,
2593	epsilon);
2594
2595	DEL_PTR(poly);
2596
2597	if (frontPoly->Valid(epsilon))
2598	front.mPolys.push_back(frontPoly);
2599	else
2600	DEL_PTR(frontPoly);
2601
2602	if (backPoly->Valid(epsilon))
2603	back.mPolys.push_back(backPoly);
2604	else
2605	DEL_PTR(backPoly);
2606	}
2607
2608	break;
2609	case Polygon3::BACK_SIDE:
2610	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2611	break;
2612	case Polygon3::FRONT_SIDE:
2613	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2614	break;
2615	case Polygon3::COINCIDENT:
2616	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2617	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2618	break;
2619	default:
2620	break;
2621	}
2622	}
2623
2624	//-- finally add the new polygon to the child node geometries
2625	if (planePoly)
2626	{
2627	// add polygon with normal pointing into positive half space to back cell
2628	back.mPolys.push_back(planePoly);
2629	// add polygon with reverse orientation to front cell
2630	front.mPolys.push_back(planePoly->CreateReversePolygon());
2631	}
2632
2633	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2634	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2635	}
2636
2637	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2638	const float epsilon) const
2639	{
2640	if (!planePoly->Valid(epsilon))
2641	DEL_PTR(planePoly);
2642
2643	// polygon is split by all other planes
2644	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2645	{
2646	Plane3 plane = mPolys[i]->GetSupportingPlane();
2647
2648	/// don't use epsilon here to get exact split planes
2649	const int cf =
2650	planePoly->ClassifyPlane(plane, Limits::Small);
2651
2652	// split new polygon with all previous planes
2653	switch (cf)
2654	{
2655	case Polygon3::SPLIT:
2656	{
2657	Polygon3 *frontPoly = new Polygon3();
2658	Polygon3 *backPoly = new Polygon3();
2659
2660	planePoly->Split(plane,
2661	*frontPoly,
2662	*backPoly,
2663	epsilon);
2664
2665	// don't need anymore
2666	DEL_PTR(planePoly);
2667	DEL_PTR(frontPoly);
2668
2669	// back polygon is belonging to geometry
2670	if (backPoly->Valid(epsilon))
2671	planePoly = backPoly;
2672	else
2673	DEL_PTR(backPoly);
2674	}
2675	break;
2676	case Polygon3::FRONT_SIDE:
2677	DEL_PTR(planePoly);
2678	break;
2679	// polygon is taken as it is
2680	case Polygon3::BACK_SIDE:
2681	case Polygon3::COINCIDENT:
2682	default:
2683	break;
2684	}
2685	}
2686
2687	return planePoly;
2688	}
2689
2690
2691	ViewCell *
2692	BspTree::GetViewCell(const Vector3 &point)
2693	{
2694	if (mRoot == NULL)
2695	return NULL;
2696
2697
2698	stack<BspNode *> nodeStack;
2699	nodeStack.push(mRoot);
2700
2701	ViewCell *viewcell = NULL;
2702
2703	while (!nodeStack.empty()) {
2704	BspNode *node = nodeStack.top();
2705	nodeStack.pop();
2706
2707	if (node->IsLeaf()) {
2708	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
2709	break;
2710	} else {
2711
2712	BspInterior interior = dynamic_cast<BspInterior >(node);
2713
2714	// random decision
2715	if (interior->GetPlane().Side(point) < 0)
2716	nodeStack.push(interior->GetBack());
2717	else
2718	nodeStack.push(interior->GetFront());
2719	}
2720	}
2721
2722	return viewcell;
2723	}
2724
2725	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
2726	{
2727	Polygon3::IncludeInBox(mPolys, box);
2728	}

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