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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 574

Revision 574, 69.1 KB checked in by mattausch, 18 years ago (diff)
finished function for view cell construction removed bsp rays from vspbspmanager

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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
13	#include <stack>
14
15	#include "Exporter.h"
16	#include "Plane3.h"
17
18	//-- static members
19
20	int BspNode::sMailId = 1;
21
22	/** Evaluates split plane classification with respect to the plane's
23	contribution for a minimum number splits in the tree.
24	*/
25	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
26	/** Evaluates split plane classification with respect to the plane's
27	contribution for a balanced tree.
28	*/
29	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
30
31	/** Evaluates split plane classification with respect to the plane's
32	contribution for a minimum number of ray splits.
33	*/
34	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
35	/** Evaluates split plane classification with respect to the plane's
36	contribution for balanced rays.
37	*/
38	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
39
40	int BspTree::sFrontId = 0;
41	int BspTree::sBackId = 0;
42	int BspTree::sFrontAndBackId = 0;
43
44
45	/****************************************************************/
46	/* class BspNode implementation */
47	/****************************************************************/
48
49
50	BspNode::BspNode():
51	mParent(NULL), mTreeValid(true)
52	{}
53
54	BspNode::BspNode(BspInterior *parent):
55	mParent(parent), mTreeValid(true)
56	{}
57
58
59	bool BspNode::IsRoot() const
60	{
61	return mParent == NULL;
62	}
63
64
65	BspInterior *BspNode::GetParent()
66	{
67	return mParent;
68	}
69
70
71	void BspNode::SetParent(BspInterior *parent)
72	{
73	mParent = parent;
74	}
75
76
77	bool BspNode::IsSibling(BspNode *n) const
78	{
79	return ((this != n) && mParent &&
80	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
81	}
82
83
84	int BspNode::GetDepth() const
85	{
86	int depth = 0;
87	BspNode *p = mParent;
88
89	while (p)
90	{
91	p = p->mParent;
92	++ depth;
93	}
94
95	return depth;
96	}
97
98
99	bool BspNode::TreeValid() const
100	{
101	return mTreeValid;
102	}
103
104
105	void BspNode::SetTreeValid(const bool v)
106	{
107	mTreeValid = v;
108	}
109
110
111	/****************************************************************/
112	/* class BspInterior implementation */
113	/****************************************************************/
114
115
116	BspInterior::BspInterior(const Plane3 &plane):
117	mPlane(plane), mFront(NULL), mBack(NULL)
118	{}
119
120	BspInterior::~BspInterior()
121	{
122	DEL_PTR(mFront);
123	DEL_PTR(mBack);
124	}
125
126	bool BspInterior::IsLeaf() const
127	{
128	return false;
129	}
130
131	BspNode *BspInterior::GetBack()
132	{
133	return mBack;
134	}
135
136	BspNode *BspInterior::GetFront()
137	{
138	return mFront;
139	}
140
141	Plane3 BspInterior::GetPlane() const
142	{
143	return mPlane;
144	}
145
146	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
147	{
148	if (mBack == oldChild)
149	mBack = newChild;
150	else
151	mFront = newChild;
152	}
153
154	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
155	{
156	mBack = b;
157	mFront = f;
158	}
159
160	/****************************************************************/
161	/* class BspLeaf implementation */
162	/****************************************************************/
163
164
165	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
166	{
167	}
168
169
170	BspLeaf::~BspLeaf()
171	{
172	DEL_PTR(mPvs);
173	}
174
175
176	BspLeaf::BspLeaf(BspViewCell *viewCell):
177	mViewCell(viewCell)
178	{
179	}
180
181
182	BspLeaf::BspLeaf(BspInterior *parent):
183	BspNode(parent), mViewCell(NULL), mPvs(NULL)
184	{}
185
186
187
188	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
189	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
190	{
191	}
192
193	BspViewCell *BspLeaf::GetViewCell() const
194	{
195	return mViewCell;
196	}
197
198	void BspLeaf::SetViewCell(BspViewCell *viewCell)
199	{
200	mViewCell = viewCell;
201	}
202
203
204	bool BspLeaf::IsLeaf() const
205	{
206	return true;
207	}
208
209
210	/******************************************************************/
211	/* class BspTree implementation */
212	/******************************************************************/
213
214	BspTree::BspTree():
215	mRoot(NULL),
216	mUseAreaForPvs(true),
217	mGenerateViewCells(true)
218	{
219	Randomize(); // initialise random generator for heuristics
220
221	// the view cell corresponding to unbounded space
222	mRootCell = new BspViewCell();
223
224	//-- termination criteria for autopartition
225	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
226	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
227	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
228	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
229	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
230	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
231	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
232
233	//-- factors for bsp tree split plane heuristics
234	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
235	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
236	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
237	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
238	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
239	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
240	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
241	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
242	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
243	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
244
245	//-- termination criteria for axis aligned split
246	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
247	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
248	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
249	mTermMinPolysForAxisAligned);
250	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
251	mTermMinRaysForAxisAligned);
252	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
253	mTermMinObjectsForAxisAligned);
254	//-- partition criteria
255	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
256	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
257	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
258	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
259	environment->GetIntValue("BspTree.maxTests", mMaxTests);
260
261	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
262
263	Debug << "BSP max depth: " << mTermMaxDepth << endl;
264	Debug << "BSP min PVS: " << mTermMinPvs << endl;
265	Debug << "BSP min area: " << mTermMinArea << endl;
266	Debug << "BSP max polys: " << mTermMinPolys << endl;
267	Debug << "BSP max rays: " << mTermMinRays << endl;
268	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
269	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
270
271	Debug << "Split plane strategy: ";
272	if (mSplitPlaneStrategy & RANDOM_POLYGON)
273	Debug << "random polygon ";
274	if (mSplitPlaneStrategy & AXIS_ALIGNED)
275	Debug << "axis aligned ";
276	if (mSplitPlaneStrategy & LEAST_SPLITS)
277	Debug << "least splits ";
278	if (mSplitPlaneStrategy & BALANCED_POLYS)
279	Debug << "balanced polygons ";
280	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
281	Debug << "balanced view cells ";
282	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
283	Debug << "largest polygon area ";
284	if (mSplitPlaneStrategy & VERTICAL_AXIS)
285	Debug << "vertical axis ";
286	if (mSplitPlaneStrategy & BLOCKED_RAYS)
287	Debug << "blocked rays ";
288	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
289	Debug << "least ray splits ";
290	if (mSplitPlaneStrategy & BALANCED_RAYS)
291	Debug << "balanced rays ";
292	if (mSplitPlaneStrategy & PVS)
293	Debug << "pvs";
294
295	Debug << endl;
296	}
297
298
299	const BspTreeStatistics &BspTree::GetStatistics() const
300	{
301	return mStat;
302	}
303
304
305	int BspTree::SplitPolygons(const Plane3 &plane,
306	PolygonContainer &polys,
307	PolygonContainer &frontPolys,
308	PolygonContainer &backPolys,
309	PolygonContainer &coincident) const
310	{
311	int splits = 0;
312
313	#ifdef _Debug
314	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
315	#endif
316	PolygonContainer::const_iterator it, it_end = polys.end();
317
318	for (it = polys.begin(); it != polys.end(); ++ it)
319	{
320	Polygon3 poly = it;
321
322	//-- classify polygon
323	const int cf = poly->ClassifyPlane(plane, mEpsilon);
324
325	switch (cf)
326	{
327	case Polygon3::COINCIDENT:
328	coincident.push_back(poly);
329	break;
330	case Polygon3::FRONT_SIDE:
331	frontPolys.push_back(poly);
332	break;
333	case Polygon3::BACK_SIDE:
334	backPolys.push_back(poly);
335	break;
336	case Polygon3::SPLIT:
337	{
338	Polygon3 *front_piece = new Polygon3(poly->mParent);
339	Polygon3 *back_piece = new Polygon3(poly->mParent);
340
341	//-- split polygon into front and back part
342	poly->Split(plane,
343	*front_piece,
344	*back_piece,
345	mEpsilon);
346
347	++ splits; // increase number of splits
348
349	//-- inherit rays from parent polygon for blocked ray criterium
350	poly->InheritRays(front_piece, back_piece);
351
352	// check if polygons still valid
353	if (front_piece->Valid(mEpsilon))
354	frontPolys.push_back(front_piece);
355	else
356	DEL_PTR(front_piece);
357
358	if (back_piece->Valid(mEpsilon))
359	backPolys.push_back(back_piece);
360	else
361	DEL_PTR(back_piece);
362
363	#ifdef _DEBUG
364	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
365	#endif
366	DEL_PTR(poly);
367	}
368	break;
369	default:
370	Debug << "SHOULD NEVER COME HERE\n";
371	break;
372	}
373	}
374
375	return splits;
376	}
377
378
379	void BspTreeStatistics::Print(ostream &app) const
380	{
381	app << "===== BspTree statistics ===============\n";
382
383	app << setprecision(4);
384
385	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
386
387	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
388
389	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
390
391	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
392
393	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
394
395	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
396
397	app << "#N_SPLITS ( Number of splits in axes x y z\n";
398
399	for (int i = 0; i < 3; ++ i)
400	app << splits[i] << " ";
401	app << endl;
402
403	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
404	<< maxDepthNodes * 100 / (double)Leaves() << endl;
405
406	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
407	<< minPvsNodes * 100 / (double)Leaves() << endl;
408
409	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
410	<< minRaysNodes * 100 / (double)Leaves() << endl;
411
412	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
413	<< maxCostNodes * 100 / (double)Leaves() << endl;
414
415	app << "#N_PMINAREALEAVES ( Percentage of leaves with mininum probability )\n"
416	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
417
418	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
419	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
420
421	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
422
423	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
424
425	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
426
427	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
428
429	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
430
431	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
432	//app << "#N_PVS: " << pvs << endl;
433
434	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
435	(polys + polySplits) / (double)polys << endl;
436
437	app << "===== END OF BspTree statistics ==========\n";
438	}
439
440
441	BspTree::~BspTree()
442	{
443	DEL_PTR(mRoot);
444
445	// HACK: view cells not generated => root cell not used
446	if (mGenerateViewCells)
447	DEL_PTR(mRootCell);
448	}
449
450	BspViewCell *BspTree::GetRootCell() const
451	{
452	return mRootCell;
453	}
454
455	void BspTree::InsertViewCell(ViewCell *viewCell)
456	{
457	PolygonContainer *polys = new PolygonContainer();
458
459	// don't generate new view cell, insert this one
460	mGenerateViewCells = false;
461	// extract polygons that guide the split process
462	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
463	mBox.Include(viewCell->GetBox()); // add to BSP aabb
464
465	InsertPolygons(polys);
466	}
467
468	void BspTree::InsertPolygons(PolygonContainer *polys)
469	{
470	BspTraversalStack tStack;
471
472	// traverse existing tree or create new tree
473	if (!mRoot)
474	mRoot = new BspLeaf();
475
476	tStack.push(BspTraversalData(mRoot,
477	polys,
478	0,
479	mRootCell,
480	new BoundedRayContainer(),
481	0,
482	mBox.SurfaceArea(),
483	new BspNodeGeometry()));
484
485	while (!tStack.empty())
486	{
487	// filter polygons donw the tree
488	BspTraversalData tData = tStack.top();
489	tStack.pop();
490
491	if (!tData.mNode->IsLeaf())
492	{
493	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
494
495	//-- filter view cell polygons down the tree until a leaf is reached
496	if (!tData.mPolygons->empty())
497	{
498	PolygonContainer *frontPolys = new PolygonContainer();
499	PolygonContainer *backPolys = new PolygonContainer();
500	PolygonContainer coincident;
501
502	int splits = 0;
503
504	// split viewcell polygons with respect to split plane
505	splits += SplitPolygons(interior->GetPlane(),
506	*tData.mPolygons,
507	*frontPolys,
508	*backPolys,
509	coincident);
510
511	// extract view cells associated with the split polygons
512	ViewCell *frontViewCell = mRootCell;
513	ViewCell *backViewCell = mRootCell;
514
515	BspTraversalData frontData(interior->GetFront(),
516	frontPolys,
517	tData.mDepth + 1,
518	mRootCell,
519	tData.mRays,
520	tData.mPvs,
521	mBox.SurfaceArea(),
522	new BspNodeGeometry());
523
524	BspTraversalData backData(interior->GetBack(),
525	backPolys,
526	tData.mDepth + 1,
527	mRootCell,
528	tData.mRays,
529	tData.mPvs,
530	mBox.SurfaceArea(),
531	new BspNodeGeometry());
532
533	if (!mGenerateViewCells)
534	{
535	ExtractViewCells(frontData,
536	backData,
537	coincident,
538	interior->mPlane);
539	}
540
541	// don't need coincident polygons anymore
542	CLEAR_CONTAINER(coincident);
543
544	mStat.polySplits += splits;
545
546	// push the children on the stack
547	tStack.push(frontData);
548	tStack.push(backData);
549	}
550
551	// cleanup
552	DEL_PTR(tData.mPolygons);
553	DEL_PTR(tData.mRays);
554	}
555	else
556	{
557	// reached leaf => subdivide current viewcell
558	BspNode *subRoot = Subdivide(tStack, tData);
559	}
560	}
561	}
562
563	int BspTree::AddMeshToPolygons(Mesh *mesh,
564	PolygonContainer &polys,
565	MeshInstance *parent)
566	{
567	FaceContainer::const_iterator fi;
568
569	// copy the face data to polygons
570	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
571	{
572	Polygon3 poly = new Polygon3((fi), mesh);
573
574	if (poly->Valid(mEpsilon))
575	{
576	poly->mParent = parent; // set parent intersectable
577	polys.push_back(poly);
578	}
579	else
580	DEL_PTR(poly);
581	}
582	return (int)mesh->mFaces.size();
583	}
584
585	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
586	PolygonContainer &polys,
587	int maxObjects)
588	{
589	int limit = (maxObjects > 0) ?
590	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
591
592	int polysSize = 0;
593
594	for (int i = 0; i < limit; ++ i)
595	{
596	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
597	{
598	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
599	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
600	}
601	}
602
603	return polysSize;
604	}
605
606	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
607	{
608	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
609
610	for (int i = 0; i < limit; ++i)
611	{
612	Intersectable object = objects[i];//it;
613	Mesh *mesh = NULL;
614
615	switch (object->Type()) // extract the meshes
616	{
617	case Intersectable::MESH_INSTANCE:
618	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
619	break;
620	case Intersectable::VIEW_CELL:
621	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
622	break;
623	// TODO: handle transformed mesh instances
624	default:
625	Debug << "intersectable type not supported" << endl;
626	break;
627	}
628
629	if (mesh) // copy the mesh data to polygons
630	{
631	mBox.Include(object->GetBox()); // add to BSP tree aabb
632	AddMeshToPolygons(mesh, polys, mRootCell);
633	}
634	}
635
636	return (int)polys.size();
637	}
638
639	void BspTree::Construct(const ViewCellContainer &viewCells)
640	{
641	mStat.nodes = 1;
642	mBox.Initialize(); // initialise bsp tree bounding box
643
644	// copy view cell meshes into one big polygon soup
645	PolygonContainer *polys = new PolygonContainer();
646	mStat.polys = AddToPolygonSoup(viewCells, *polys);
647
648	// view cells are given
649	mGenerateViewCells = false;
650	// construct tree from the view cell polygons
651	Construct(polys, new BoundedRayContainer());
652	}
653
654
655	void BspTree::Construct(const ObjectContainer &objects)
656	{
657	mStat.nodes = 1;
658	mBox.Initialize(); // initialise bsp tree bounding box
659
660	PolygonContainer *polys = new PolygonContainer();
661
662	mGenerateViewCells = true;
663	// copy mesh instance polygons into one big polygon soup
664	mStat.polys = AddToPolygonSoup(objects, *polys);
665
666	// construct tree from polygon soup
667	Construct(polys, new BoundedRayContainer());
668	}
669
670	void BspTree::Construct(const RayContainer &sampleRays)
671	{
672	mStat.nodes = 1;
673	mBox.Initialize(); // initialise BSP tree bounding box
674
675	PolygonContainer *polys = new PolygonContainer();
676	BoundedRayContainer *rays = new BoundedRayContainer();
677
678	RayContainer::const_iterator rit, rit_end = sampleRays.end();
679
680	// generate view cells
681	mGenerateViewCells = true;
682
683	long startTime = GetTime();
684
685	Debug << "** Extracting polygons from rays **\n";
686
687	std::map<Face , Polygon3 > facePolyMap;
688
689	//-- extract polygons intersected by the rays
690	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
691	{
692	Ray ray = rit;
693
694	// get ray-face intersection. Store polygon representing the rays together
695	// with rays intersecting the face.
696	if (!ray->intersections.empty())
697	{
698	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
699	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
700
701	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
702
703	if (it != facePolyMap.end())
704	{
705	//store rays if needed for heuristics
706	if (mSplitPlaneStrategy & BLOCKED_RAYS)
707	(*it).second->mPiercingRays.push_back(ray);
708	}
709	else
710	{ //store rays if needed for heuristics
711	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
712	poly->mParent = obj;
713	polys->push_back(poly);
714
715	if (mSplitPlaneStrategy & BLOCKED_RAYS)
716	poly->mPiercingRays.push_back(ray);
717
718	facePolyMap[face] = poly;
719	}
720	}
721	}
722
723	facePolyMap.clear();
724
725	// compute bounding box
726	Polygon3::IncludeInBox(*polys, mBox);
727
728	//-- store rays
729	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
730	{
731	Ray ray = rit;
732	ray->SetId(-1); // reset id
733
734	float minT, maxT;
735	if (mBox.GetRaySegment(*ray, minT, maxT))
736	rays->push_back(new BoundedRay(ray, minT, maxT));
737	}
738
739	mStat.polys = (int)polys->size();
740
741	Debug << "** Finished polygon extraction **" << endl;
742	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
743	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
744
745	Construct(polys, rays);
746	}
747
748	void BspTree::Construct(const ObjectContainer &objects, const RayContainer &sampleRays)
749	{
750	mStat.nodes = 1;
751	mBox.Initialize(); // initialise BSP tree bounding box
752
753	BoundedRayContainer *rays = new BoundedRayContainer();
754	PolygonContainer *polys = new PolygonContainer();
755
756	mGenerateViewCells = true;
757
758	// copy mesh instance polygons into one big polygon soup
759	mStat.polys = AddToPolygonSoup(objects, *polys);
760
761	RayContainer::const_iterator rit, rit_end = sampleRays.end();
762
763	//-- store rays
764	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
765	{
766	Ray ray = rit;
767	ray->SetId(-1); // reset id
768
769	float minT, maxT;
770	if (mBox.GetRaySegment(*ray, minT, maxT))
771	rays->push_back(new BoundedRay(ray, minT, maxT));
772	}
773
774	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
775	Construct(polys, rays);
776	}
777
778	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
779	{
780	BspTraversalStack tStack;
781
782	mRoot = new BspLeaf();
783
784	// constrruct root node geometry
785	BspNodeGeometry *geom = new BspNodeGeometry();
786	ConstructGeometry(mRoot, *geom);
787
788	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
789	ComputePvsSize(*rays), geom->GetArea(), geom);
790
791	tStack.push(tData);
792
793	mStat.Start();
794	cout << "Contructing bsp tree ... ";
795	long startTime = GetTime();
796	while (!tStack.empty())
797	{
798	tData = tStack.top();
799
800	tStack.pop();
801
802	// subdivide leaf node
803	BspNode *r = Subdivide(tStack, tData);
804
805	if (r == mRoot)
806	Debug << "BSP tree construction time spent at root: " << TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
807	}
808
809	cout << "finished\n";
810
811	mStat.Stop();
812	}
813
814	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
815	{
816	return
817	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
818	((int)data.mRays->size() <= mTermMinRays) \|\|
819	(data.mPvs <= mTermMinPvs) \|\|
820	(data.mArea <= mTermMinArea) \|\|
821	(data.mDepth >= mTermMaxDepth) \|\|
822	(data.GetAvgRayContribution() < mTermMaxRayContribution));
823	}
824
825	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
826	{
827	//-- terminate traversal
828	if (TerminationCriteriaMet(tData))
829	{
830	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
831
832	BspViewCell *viewCell;
833
834	// generate new view cell for each leaf
835	if (mGenerateViewCells)
836	viewCell = new BspViewCell();
837	else
838	// add view cell to leaf
839	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
840
841	leaf->SetViewCell(viewCell);
842	viewCell->mLeaves.push_back(leaf);
843
844	//-- add pvs
845	if (viewCell != mRootCell)
846	{
847	int conSamp = 0, sampCon = 0;
848	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
849
850	mStat.contributingSamples += conSamp;
851	mStat.sampleContributions += sampCon;
852	}
853
854	EvaluateLeafStats(tData);
855
856	//-- clean up
857
858	// discard polygons
859	CLEAR_CONTAINER(*tData.mPolygons);
860	// discard rays
861	CLEAR_CONTAINER(*tData.mRays);
862
863	DEL_PTR(tData.mPolygons);
864	DEL_PTR(tData.mRays);
865	DEL_PTR(tData.mGeometry);
866
867	return leaf;
868	}
869
870	//-- continue subdivision
871	PolygonContainer coincident;
872
873	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
874	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
875	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
876	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
877
878	// create new interior node and two leaf nodes
879	BspInterior *interior =
880	SubdivideNode(tData, tFrontData, tBackData, coincident);
881
882	#ifdef _DEBUG
883	// if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
884	// { for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
885	// Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
886	// Debug << endl;}
887	#endif
888
889	// extract view cells from coincident polygons according to plane normal
890	// only if front or back polygons are empty
891	if (!mGenerateViewCells)
892	{
893	ExtractViewCells(tFrontData,
894	tBackData,
895	coincident,
896	interior->mPlane);
897	}
898
899	// don't need coincident polygons anymory
900	CLEAR_CONTAINER(coincident);
901
902	// push the children on the stack
903	tStack.push(tFrontData);
904	tStack.push(tBackData);
905
906	// cleanup
907	DEL_PTR(tData.mNode);
908
909	DEL_PTR(tData.mPolygons);
910	DEL_PTR(tData.mRays);
911	DEL_PTR(tData.mGeometry);
912
913	return interior;
914	}
915
916	void BspTree::ExtractViewCells(BspTraversalData &frontData,
917	BspTraversalData &backData,
918	const PolygonContainer &coincident,
919	const Plane3 &splitPlane) const
920	{
921	// if not empty, tree is further subdivided => don't have to find view cell
922	bool foundFront = !frontData.mPolygons->empty();
923	bool foundBack = !frontData.mPolygons->empty();
924
925	PolygonContainer::const_iterator it =
926	coincident.begin(), it_end = coincident.end();
927
928	//-- find first view cells in front and back leafs
929	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
930	{
931	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
932	{
933	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
934	foundBack = true;
935	}
936	else
937	{
938	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
939	foundFront = true;
940	}
941	}
942	}
943
944	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
945	BspTraversalData &frontData,
946	BspTraversalData &backData,
947	PolygonContainer &coincident)
948	{
949	mStat.nodes += 2;
950
951	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
952
953	Debug << "*********************" << endl;
954	long startTime = GetTime();
955
956	// select subdivision plane
957	BspInterior *interior =
958	new BspInterior(SelectPlane(leaf, tData));
959	Debug << "time used for split plane selection: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
960	#ifdef _DEBUG
961	Debug << interior << endl;
962	#endif
963
964
965	Debug << "number of rays: " << (int)tData.mRays->size() << endl;
966	Debug << "number of polys: " << (int)tData.mPolygons->size() << endl;
967
968	startTime = GetTime();
969
970	// subdivide rays into front and back rays
971	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
972
973	Debug << "time used for rays splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
974
975	startTime = GetTime();
976	// subdivide polygons with plane
977	mStat.polySplits += SplitPolygons(interior->GetPlane(),
978	*tData.mPolygons,
979	*frontData.mPolygons,
980	*backData.mPolygons,
981	coincident);
982
983	Debug << "time used for polygon splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
984
985	// compute pvs
986	frontData.mPvs = ComputePvsSize(*frontData.mRays);
987	backData.mPvs = ComputePvsSize(*backData.mRays);
988
989	// split geometry and compute area
990	if (1)
991	{
992	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
993	*backData.mGeometry,
994	interior->mPlane,
995	mBox,
996	mEpsilon);
997
998
999	frontData.mArea = frontData.mGeometry->GetArea();
1000	backData.mArea = backData.mGeometry->GetArea();
1001	}
1002
1003	// compute accumulated ray length
1004	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
1005	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
1006
1007	//-- create front and back leaf
1008
1009	BspInterior *parent = leaf->GetParent();
1010
1011	// replace a link from node's parent
1012	if (!leaf->IsRoot())
1013	{
1014	parent->ReplaceChildLink(leaf, interior);
1015	interior->SetParent(parent);
1016	}
1017	else // new root
1018	{
1019	mRoot = interior;
1020	}
1021
1022	// and setup child links
1023	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1024
1025	frontData.mNode = interior->GetFront();
1026	backData.mNode = interior->GetBack();
1027
1028	//DEL_PTR(leaf);
1029	return interior;
1030	}
1031
1032	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1033	const int axis,
1034	vector<SortableEntry> &splitCandidates) const
1035	{
1036	splitCandidates.clear();
1037
1038	int requestedSize = 2 * (int)polys.size();
1039	// creates a sorted split candidates array
1040	splitCandidates.reserve(requestedSize);
1041
1042	PolygonContainer::const_iterator it, it_end = polys.end();
1043
1044	AxisAlignedBox3 box;
1045
1046	// insert all queries
1047	for(it = polys.begin(); it != it_end; ++ it)
1048	{
1049	box.Initialize();
1050	box.Include((it));
1051
1052	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1053	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1054	}
1055
1056	stable_sort(splitCandidates.begin(), splitCandidates.end());
1057	}
1058
1059
1060	float BspTree::BestCostRatio(const PolygonContainer &polys,
1061	const AxisAlignedBox3 &box,
1062	const int axis,
1063	float &position,
1064	int &objectsBack,
1065	int &objectsFront) const
1066	{
1067	vector<SortableEntry> splitCandidates;
1068
1069	SortSplitCandidates(polys, axis, splitCandidates);
1070
1071	// go through the lists, count the number of objects left and right
1072	// and evaluate the following cost funcion:
1073	// C = ct_div_ci + (ol + or)/queries
1074
1075	int objectsLeft = 0, objectsRight = (int)polys.size();
1076
1077	float minBox = box.Min(axis);
1078	float maxBox = box.Max(axis);
1079	float boxArea = box.SurfaceArea();
1080
1081	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1082	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1083
1084	float minSum = 1e20f;
1085	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1086
1087	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1088	{
1089	switch ((*ci).type)
1090	{
1091	case SortableEntry::POLY_MIN:
1092	++ objectsLeft;
1093	break;
1094	case SortableEntry::POLY_MAX:
1095	-- objectsRight;
1096	break;
1097	default:
1098	break;
1099	}
1100
1101	if ((ci).value > minBand && (ci).value < maxBand)
1102	{
1103	AxisAlignedBox3 lbox = box;
1104	AxisAlignedBox3 rbox = box;
1105	lbox.SetMax(axis, (*ci).value);
1106	rbox.SetMin(axis, (*ci).value);
1107
1108	const float sum = objectsLeft * lbox.SurfaceArea() +
1109	objectsRight * rbox.SurfaceArea();
1110
1111	if (sum < minSum)
1112	{
1113	minSum = sum;
1114	position = (*ci).value;
1115
1116	objectsBack = objectsLeft;
1117	objectsFront = objectsRight;
1118	}
1119	}
1120	}
1121
1122	const float oldCost = (float)polys.size();
1123	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1124	const float ratio = newCost / oldCost;
1125
1126
1127	#if 0
1128	Debug << "====================" << endl;
1129	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1130	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1131	#endif
1132	return ratio;
1133	}
1134
1135	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1136	const PolygonContainer &polys) const
1137	{
1138	AxisAlignedBox3 box;
1139	box.Initialize();
1140
1141	// create bounding box of region
1142	Polygon3::IncludeInBox(polys, box);
1143
1144	int objectsBack = 0, objectsFront = 0;
1145	int axis = 0;
1146	float costRatio = MAX_FLOAT;
1147	Vector3 position;
1148
1149	//-- area subdivision
1150	for (int i = 0; i < 3; ++ i)
1151	{
1152	float p = 0;
1153	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1154
1155	if (r < costRatio)
1156	{
1157	costRatio = r;
1158	axis = i;
1159	position = p;
1160	}
1161	}
1162
1163	if (costRatio >= mMaxCostRatio)
1164	return false;
1165
1166	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1167	plane = Plane3(norm, position);
1168
1169	return true;
1170	}
1171
1172
1173	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1174	{
1175	if (data.mPolygons->empty() && data.mRays->empty())
1176	{
1177	Debug << "Warning: No autopartition polygon candidate available\n";
1178
1179	// return axis aligned split
1180	AxisAlignedBox3 box;
1181	box.Initialize();
1182
1183	// create bounding box of region
1184	Polygon3::IncludeInBox(*data.mPolygons, box);
1185
1186	const int axis = box.Size().DrivingAxis();
1187	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1188
1189	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1190	return Plane3(norm, position);
1191	}
1192
1193	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1194	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1195	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1196	((mTermMinObjectsForAxisAligned < 0) \|\|
1197	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1198	{
1199	Plane3 plane;
1200	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1201	return plane;
1202	}
1203
1204	// simplest strategy: just take next polygon
1205	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1206	{
1207	if (!data.mPolygons->empty())
1208	{
1209	Polygon3 *nextPoly =
1210	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1211	return nextPoly->GetSupportingPlane();
1212	}
1213	else
1214	{
1215	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1216	BoundedRay bRay = (data.mRays)[candidateIdx];
1217
1218	Ray *ray = bRay->mRay;
1219
1220	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1221	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1222
1223	const Vector3 pt = (maxPt + minPt) * 0.5;
1224
1225	const Vector3 normal = ray->GetDir();
1226
1227	return Plane3(normal, pt);
1228	}
1229
1230	return Plane3();
1231	}
1232
1233	// use heuristics to find appropriate plane
1234	return SelectPlaneHeuristics(leaf, data);
1235	}
1236
1237
1238	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1239	{
1240	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1241	BoundedRay *bRay = rays[candidateIdx];
1242	Ray *ray = bRay->mRay;
1243
1244	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1245	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1246
1247	const Vector3 pt = (maxPt + minPt) * 0.5;
1248
1249	const Vector3 normal = ray->GetDir();
1250
1251	return Plane3(normal, pt);
1252	}
1253
1254	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1255	{
1256	Vector3 pt[3];
1257	int idx[3];
1258	int cmaxT = 0;
1259	int cminT = 0;
1260	bool chooseMin = false;
1261
1262	for (int j = 0; j < 3; j ++)
1263	{
1264	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1265
1266	if (idx[j] >= (int)rays.size())
1267	{
1268	idx[j] -= (int)rays.size();
1269	chooseMin = (cminT < 2);
1270	}
1271	else
1272	chooseMin = (cmaxT < 2);
1273
1274	BoundedRay *bRay = rays[idx[j]];
1275	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1276	bRay->mRay->Extrap(bRay->mMaxT);
1277	}
1278
1279	return Plane3(pt[0], pt[1], pt[2]);
1280	}
1281
1282	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1283	{
1284	Vector3 pt[3];
1285
1286	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1287	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1288
1289	// check if rays different
1290	if (idx1 == idx2)
1291	idx2 = (idx2 + 1) % (int)rays.size();
1292
1293	const BoundedRay *ray1 = rays[idx1];
1294	const BoundedRay *ray2 = rays[idx2];
1295
1296	// normal vector of the plane parallel to both lines
1297	const Vector3 norm =
1298	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1299
1300	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1301	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1302
1303	// vector from line 1 to line 2
1304	const Vector3 vd = orig1 - orig2;
1305
1306	// project vector on normal to get distance
1307	const float dist = DotProd(vd, norm);
1308
1309	// point on plane lies halfway between the two planes
1310	const Vector3 planePt = orig1 + norm * dist * 0.5;
1311
1312	return Plane3(norm, planePt);
1313	}
1314
1315
1316	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1317	{
1318	float lowestCost = MAX_FLOAT;
1319	Plane3 bestPlane;
1320	// intermediate plane
1321	Plane3 plane;
1322
1323	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1324	int maxIdx = (int)data.mPolygons->size();
1325
1326	for (int i = 0; i < limit; ++ i)
1327	{
1328	// assure that no index is taken twice
1329	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1330	//Debug << "current Idx: " << maxIdx << " cand idx " << candidateIdx << endl;
1331
1332	Polygon3 poly = (data.mPolygons)[candidateIdx];
1333
1334	// swap candidate to the end to avoid testing same plane
1335	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1336
1337	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1338
1339	// evaluate current candidate
1340	const float candidateCost =
1341	SplitPlaneCost(poly->GetSupportingPlane(), data);
1342
1343	if (candidateCost < lowestCost)
1344	{
1345	bestPlane = poly->GetSupportingPlane();
1346	lowestCost = candidateCost;
1347	}
1348	}
1349
1350	//-- choose candidate planes extracted from rays
1351	for (int i = 0; i < mMaxRayCandidates; ++ i)
1352	{
1353	plane = ChooseCandidatePlane3(*data.mRays);
1354	const float candidateCost = SplitPlaneCost(plane, data);
1355
1356	if (candidateCost < lowestCost)
1357	{
1358	bestPlane = plane;
1359	lowestCost = candidateCost;
1360	}
1361	}
1362
1363	#ifdef _DEBUG
1364	Debug << "plane lowest cost: " << lowestCost << endl;
1365	#endif
1366
1367	return bestPlane;
1368	}
1369
1370
1371	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1372	const PolygonContainer &polys) const
1373	{
1374	float val = 0;
1375
1376	float sumBalancedPolys = 0;
1377	float sumSplits = 0;
1378	float sumPolyArea = 0;
1379	float sumBalancedViewCells = 0;
1380	float sumBlockedRays = 0;
1381	float totalBlockedRays = 0;
1382	//float totalArea = 0;
1383	int totalViewCells = 0;
1384
1385	// need three unique ids for each type of view cell
1386	// for balanced view cells criterium
1387	ViewCell::NewMail();
1388	const int backId = ViewCell::sMailId;
1389	ViewCell::NewMail();
1390	const int frontId = ViewCell::sMailId;
1391	ViewCell::NewMail();
1392	const int frontAndBackId = ViewCell::sMailId;
1393
1394	bool useRand;;
1395	int limit;
1396
1397	// choose test polyongs randomly if over threshold
1398	if ((int)polys.size() > mMaxTests)
1399	{
1400	useRand = true;
1401	limit = mMaxTests;
1402	}
1403	else
1404	{
1405	useRand = false;
1406	limit = (int)polys.size();
1407	}
1408
1409	for (int i = 0; i < limit; ++ i)
1410	{
1411	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1412
1413	Polygon3 *poly = polys[testIdx];
1414
1415	const int classification =
1416	poly->ClassifyPlane(candidatePlane, mEpsilon);
1417
1418	if (mSplitPlaneStrategy & BALANCED_POLYS)
1419	sumBalancedPolys += sBalancedPolysTable[classification];
1420
1421	if (mSplitPlaneStrategy & LEAST_SPLITS)
1422	sumSplits += sLeastPolySplitsTable[classification];
1423
1424	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1425	{
1426	if (classification == Polygon3::COINCIDENT)
1427	sumPolyArea += poly->GetArea();
1428	//totalArea += area;
1429	}
1430
1431	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1432	{
1433	const float blockedRays = (float)poly->mPiercingRays.size();
1434
1435	if (classification == Polygon3::COINCIDENT)
1436	sumBlockedRays += blockedRays;
1437
1438	totalBlockedRays += blockedRays;
1439	}
1440
1441	// assign view cells to back or front according to classificaion
1442	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1443	{
1444	MeshInstance *viewCell = poly->mParent;
1445
1446	// assure that we only count a view cell
1447	// once for the front and once for the back side of the plane
1448	if (classification == Polygon3::FRONT_SIDE)
1449	{
1450	if ((viewCell->mMailbox != frontId) &&
1451	(viewCell->mMailbox != frontAndBackId))
1452	{
1453	sumBalancedViewCells += 1.0;
1454
1455	if (viewCell->mMailbox != backId)
1456	viewCell->mMailbox = frontId;
1457	else
1458	viewCell->mMailbox = frontAndBackId;
1459
1460	++ totalViewCells;
1461	}
1462	}
1463	else if (classification == Polygon3::BACK_SIDE)
1464	{
1465	if ((viewCell->mMailbox != backId) &&
1466	(viewCell->mMailbox != frontAndBackId))
1467	{
1468	sumBalancedViewCells -= 1.0;
1469
1470	if (viewCell->mMailbox != frontId)
1471	viewCell->mMailbox = backId;
1472	else
1473	viewCell->mMailbox = frontAndBackId;
1474
1475	++ totalViewCells;
1476	}
1477	}
1478	}
1479	}
1480
1481	const float polysSize = (float)polys.size() + Limits::Small;
1482
1483	// all values should be approx. between 0 and 1 so they can be combined
1484	// and scaled with the factors according to their importance
1485	if (mSplitPlaneStrategy & BALANCED_POLYS)
1486	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1487
1488	if (mSplitPlaneStrategy & LEAST_SPLITS)
1489	val += mLeastSplitsFactor * sumSplits / polysSize;
1490
1491	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1492	// HACK: polys.size should be total area so scaling is between 0 and 1
1493	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1494
1495	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1496	if (totalBlockedRays != 0)
1497	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1498
1499	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1500	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1501	((float)totalViewCells + Limits::Small);
1502
1503	return val;
1504	}
1505
1506
1507	inline void BspTree::GenerateUniqueIdsForPvs()
1508	{
1509	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1510	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1511	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1512	}
1513
1514
1515	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1516	const BoundedRayContainer &rays,
1517	const int pvs,
1518	const float area,
1519	const BspNodeGeometry &cell) const
1520	{
1521	float val = 0;
1522
1523	float sumBalancedRays = 0;
1524	float sumRaySplits = 0;
1525
1526	int frontPvs = 0;
1527	int backPvs = 0;
1528
1529	// probability that view point lies in child
1530	float pOverall = 0;
1531	float pFront = 0;
1532	float pBack = 0;
1533
1534	const bool pvsUseLen = false;
1535
1536	if (mSplitPlaneStrategy & PVS)
1537	{
1538	// create unique ids for pvs heuristics
1539	GenerateUniqueIdsForPvs();
1540
1541	if (mUseAreaForPvs) // use front and back cell areas to approximate volume
1542	{
1543	// construct child geometry with regard to the candidate split plane
1544	BspNodeGeometry frontCell;
1545	BspNodeGeometry backCell;
1546
1547	cell.SplitGeometry(frontCell,
1548	backCell,
1549	candidatePlane,
1550	mBox,
1551	mEpsilon);
1552
1553	pFront = frontCell.GetArea();
1554	pBack = backCell.GetArea();
1555
1556	pOverall = area;
1557	}
1558	}
1559
1560	bool useRand;
1561	int limit;
1562
1563	// choose test polyongs randomly if over threshold
1564	if ((int)rays.size() > mMaxTests)
1565	{
1566	useRand = true;
1567	limit = mMaxTests;
1568	}
1569	else
1570	{
1571	useRand = false;
1572	limit = (int)rays.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	BoundedRay *bRay = rays[testIdx];
1580
1581	Ray *ray = bRay->mRay;
1582	const float minT = bRay->mMinT;
1583	const float maxT = bRay->mMaxT;
1584
1585	Vector3 entP, extP;
1586
1587	const int cf =
1588	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1589
1590	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1591	{
1592	sumBalancedRays += sBalancedRaysTable[cf];
1593	}
1594
1595	if (mSplitPlaneStrategy & BALANCED_RAYS)
1596	{
1597	sumRaySplits += sLeastRaySplitsTable[cf];
1598	}
1599
1600	if (mSplitPlaneStrategy & PVS)
1601	{
1602	// in case the ray intersects an object
1603	// assure that we only count the object
1604	// once for the front and once for the back side of the plane
1605
1606	// add the termination object
1607	if (!ray->intersections.empty())
1608	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1609
1610	// add the source object
1611	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1612
1613	if (mUseAreaForPvs)
1614	{
1615	float len = 1;
1616
1617	if (pvsUseLen)
1618	len = SqrDistance(entP, extP);
1619
1620	// use length of rays to approximate volume
1621	if (Ray::BACK && Ray::COINCIDENT)
1622	pBack += len;
1623	if (Ray::FRONT && Ray::COINCIDENT)
1624	pFront += len;
1625	if (Ray::FRONT_BACK \|\| Ray::BACK_FRONT)
1626	{
1627	if (pvsUseLen)
1628	{
1629	const Vector3 extp = ray->Extrap(maxT);
1630	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1631
1632	const float newT = t * maxT;
1633	const float newLen = SqrDistance(ray->Extrap(newT), extp);
1634
1635	if (Ray::FRONT_BACK)
1636	{
1637	pFront += len - newLen;
1638	pBack += newLen;
1639	}
1640	else
1641	{
1642	pBack += len - newLen;
1643	pFront += newLen;
1644	}
1645	}
1646	else
1647	{
1648	++ pFront;
1649	++ pBack;
1650	}
1651	}
1652	}
1653	}
1654	}
1655
1656	const float raysSize = (float)rays.size() + Limits::Small;
1657
1658	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1659	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1660
1661	if (mSplitPlaneStrategy & BALANCED_RAYS)
1662	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1663
1664	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1665
1666	if (mSplitPlaneStrategy & PVS)
1667	{
1668	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1669
1670	// give penalty to unbalanced split
1671	if (0)
1672	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1673	(pFront < (pBack * 0.2 + Limits::Small)))
1674	val += 0.5;
1675	}
1676
1677
1678	#ifdef _DEBUG
1679	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1680	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1681	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1682	#endif
1683
1684	return val;
1685	}
1686
1687	void BspTree::AddObjToPvs(Intersectable *obj,
1688	const int cf,
1689	int &frontPvs,
1690	int &backPvs) const
1691	{
1692	if (!obj)
1693	return;
1694	// TODO: does this really belong to no pvs?
1695	//if (cf == Ray::COINCIDENT) return;
1696
1697	// object belongs to both PVS
1698	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1699	(cf == Ray::BACK_FRONT) \|\|
1700	(cf == Ray::COINCIDENT);
1701
1702	if ((cf == Ray::FRONT) \|\| bothSides)
1703	{
1704	if ((obj->mMailbox != sFrontId) &&
1705	(obj->mMailbox != sFrontAndBackId))
1706	{
1707	++ frontPvs;
1708
1709	if (obj->mMailbox == sBackId)
1710	obj->mMailbox = sFrontAndBackId;
1711	else
1712	obj->mMailbox = sFrontId;
1713	}
1714	}
1715
1716	if ((cf == Ray::BACK) \|\| bothSides)
1717	{
1718	if ((obj->mMailbox != sBackId) &&
1719	(obj->mMailbox != sFrontAndBackId))
1720	{
1721	++ backPvs;
1722
1723	if (obj->mMailbox == sFrontId)
1724	obj->mMailbox = sFrontAndBackId;
1725	else
1726	obj->mMailbox = sBackId;
1727	}
1728	}
1729	}
1730
1731	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1732	BspTraversalData &data) const
1733	{
1734	float val = 0;
1735
1736	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1737	{
1738	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1739	// we put a penalty on the dot product between the "tiny" vertical axis
1740	// and the split plane axis
1741	val += mVerticalSplitsFactor *
1742	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1743	}
1744
1745	// the following criteria loop over all polygons to find the cost value
1746	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1747	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1748	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1749	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1750	(mSplitPlaneStrategy & BLOCKED_RAYS))
1751	{
1752	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1753	}
1754
1755	// the following criteria loop over all rays to find the cost value
1756	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1757	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1758	(mSplitPlaneStrategy & PVS))
1759	{
1760	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1761	data.mArea, *data.mGeometry);
1762	}
1763
1764	// return linear combination of the sums
1765	return val;
1766	}
1767
1768	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1769	{
1770	stack<BspNode *> nodeStack;
1771	nodeStack.push(mRoot);
1772
1773	while (!nodeStack.empty())
1774	{
1775	BspNode *node = nodeStack.top();
1776
1777	nodeStack.pop();
1778
1779	if (node->IsLeaf())
1780	{
1781	BspLeaf leaf = (BspLeaf )node;
1782	leaves.push_back(leaf);
1783	}
1784	else
1785	{
1786	BspInterior interior = dynamic_cast<BspInterior >(node);
1787
1788	nodeStack.push(interior->GetBack());
1789	nodeStack.push(interior->GetFront());
1790	}
1791	}
1792	}
1793
1794
1795	AxisAlignedBox3 BspTree::GetBoundingBox() const
1796	{
1797	return mBox;
1798	}
1799
1800
1801	BspNode *BspTree::GetRoot() const
1802	{
1803	return mRoot;
1804	}
1805
1806	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1807	{
1808	// the node became a leaf -> evaluate stats for leafs
1809	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1810
1811	// store maximal and minimal depth
1812	if (data.mDepth > mStat.maxDepth)
1813	mStat.maxDepth = data.mDepth;
1814
1815	if (data.mDepth < mStat.minDepth)
1816	mStat.minDepth = data.mDepth;
1817
1818	// accumulate depth to compute average depth
1819	mStat.accumDepth += data.mDepth;
1820	// accumulate rays to compute rays / leaf
1821	mStat.accumRays += (int)data.mRays->size();
1822
1823	if (data.mDepth >= mTermMaxDepth)
1824	++ mStat.maxDepthNodes;
1825
1826	if (data.mPvs < mTermMinPvs)
1827	++ mStat.minPvsNodes;
1828
1829	if ((int)data.mRays->size() < mTermMinRays)
1830	++ mStat.minRaysNodes;
1831
1832	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1833	++ mStat.maxRayContribNodes;
1834
1835	if (data.mGeometry->GetArea() <= mTermMinArea)
1836	++ mStat.minProbabilityNodes;
1837
1838	#ifdef _DEBUG
1839	Debug << "BSP stats: "
1840	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1841	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1842	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1843	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1844	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1845	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1846	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1847	#endif
1848	}
1849
1850	int
1851	BspTree::_CastRay(Ray &ray)
1852	{
1853	int hits = 0;
1854
1855	stack<BspRayTraversalData> tStack;
1856
1857	float maxt, mint;
1858
1859	if (!mBox.GetRaySegment(ray, mint, maxt))
1860	return 0;
1861
1862	Intersectable::NewMail();
1863
1864	Vector3 entp = ray.Extrap(mint);
1865	Vector3 extp = ray.Extrap(maxt);
1866
1867	BspNode *node = mRoot;
1868	BspNode *farChild = NULL;
1869
1870	while (1)
1871	{
1872	if (!node->IsLeaf())
1873	{
1874	BspInterior in = dynamic_cast<BspInterior >(node);
1875
1876	Plane3 splitPlane = in->GetPlane();
1877	const int entSide = splitPlane.Side(entp);
1878	const int extSide = splitPlane.Side(extp);
1879
1880	if (entSide < 0)
1881	{
1882	node = in->GetBack();
1883
1884	if(extSide <= 0) // plane does not split ray => no far child
1885	continue;
1886
1887	farChild = in->GetFront(); // plane splits ray
1888
1889	} else if (entSide > 0)
1890	{
1891	node = in->GetFront();
1892
1893	if (extSide >= 0) // plane does not split ray => no far child
1894	continue;
1895
1896	farChild = in->GetBack(); // plane splits ray
1897	}
1898	else // ray and plane are coincident
1899	{
1900	// WHAT TO DO IN THIS CASE ?
1901	//break;
1902	node = in->GetFront();
1903	continue;
1904	}
1905
1906	// push data for far child
1907	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1908
1909	// find intersection of ray segment with plane
1910	float t;
1911	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
1912	maxt *= t;
1913
1914	} else // reached leaf => intersection with view cell
1915	{
1916	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1917
1918	if (!leaf->mViewCell->Mailed())
1919	{
1920	// ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1921	leaf->mViewCell->Mail();
1922	++ hits;
1923	}
1924
1925	//-- fetch the next far child from the stack
1926	if (tStack.empty())
1927	break;
1928
1929	entp = extp;
1930	mint = maxt; // NOTE: need this?
1931
1932	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1933	break;
1934
1935	BspRayTraversalData &s = tStack.top();
1936
1937	node = s.mNode;
1938	extp = s.mExitPoint;
1939	maxt = s.mMaxT;
1940
1941	tStack.pop();
1942	}
1943	}
1944
1945	return hits;
1946	}
1947
1948
1949	int BspTree::CastLineSegment(const Vector3 &origin,
1950	const Vector3 &termination,
1951	vector<ViewCell *> &viewcells)
1952	{
1953	int hits = 0;
1954	stack<BspRayTraversalData> tStack;
1955
1956	float mint = 0.0f, maxt = 1.0f;
1957
1958	Intersectable::NewMail();
1959
1960	Vector3 entp = origin;
1961	Vector3 extp = termination;
1962
1963	BspNode *node = mRoot;
1964	BspNode *farChild = NULL;
1965
1966	while (1)
1967	{
1968	if (!node->IsLeaf())
1969	{
1970	BspInterior in = dynamic_cast<BspInterior >(node);
1971
1972	Plane3 splitPlane = in->GetPlane();
1973
1974	const int entSide = splitPlane.Side(entp);
1975	const int extSide = splitPlane.Side(extp);
1976
1977	if (entSide < 0)
1978	{
1979	node = in->GetBack();
1980
1981	if(extSide <= 0) // plane does not split ray => no far child
1982	continue;
1983
1984	farChild = in->GetFront(); // plane splits ray
1985
1986	}
1987	else if (entSide > 0)
1988	{
1989	node = in->GetFront();
1990
1991	if (extSide >= 0) // plane does not split ray => no far child
1992	continue;
1993
1994	farChild = in->GetBack(); // plane splits ray
1995	}
1996	else // ray and plane are coincident
1997	{
1998	// WHAT TO DO IN THIS CASE ?
1999	//break;
2000	node = in->GetFront();
2001	continue;
2002	}
2003
2004	// push data for far child
2005	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2006
2007	// find intersection of ray segment with plane
2008	float t;
2009	extp = splitPlane.FindIntersection(origin, extp, &t);
2010	maxt *= t;
2011	}
2012	else
2013	{
2014	// reached leaf => intersection with view cell
2015	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2016
2017	if (!leaf->mViewCell->Mailed())
2018	{
2019	viewcells.push_back(leaf->mViewCell);
2020	leaf->mViewCell->Mail();
2021	hits++;
2022	}
2023
2024	//-- fetch the next far child from the stack
2025	if (tStack.empty())
2026	break;
2027
2028	entp = extp;
2029	mint = maxt; // NOTE: need this?
2030
2031	BspRayTraversalData &s = tStack.top();
2032
2033	node = s.mNode;
2034	extp = s.mExitPoint;
2035	maxt = s.mMaxT;
2036
2037	tStack.pop();
2038	}
2039	}
2040	return hits;
2041	}
2042
2043	bool BspTree::Export(const string filename)
2044	{
2045	Exporter *exporter = Exporter::GetExporter(filename);
2046
2047	if (exporter)
2048	{
2049	exporter->ExportBspTree(*this);
2050	return true;
2051	}
2052
2053	return false;
2054	}
2055
2056	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2057	{
2058	stack<BspNode *> nodeStack;
2059	nodeStack.push(mRoot);
2060
2061	ViewCell::NewMail();
2062
2063	while (!nodeStack.empty())
2064	{
2065	BspNode *node = nodeStack.top();
2066	nodeStack.pop();
2067
2068	if (node->IsLeaf())
2069	{
2070	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2071
2072	if (!viewCell->Mailed())
2073	{
2074	viewCell->Mail();
2075	viewCells.push_back(viewCell);
2076	}
2077	}
2078	else
2079	{
2080	BspInterior interior = dynamic_cast<BspInterior >(node);
2081
2082	nodeStack.push(interior->GetFront());
2083	nodeStack.push(interior->GetBack());
2084	}
2085	}
2086	}
2087
2088
2089	BspTreeStatistics &BspTree::GetStat()
2090	{
2091	return mStat;
2092	}
2093
2094
2095	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2096	{
2097	float len = 0;
2098
2099	BoundedRayContainer::const_iterator it, it_end = rays.end();
2100
2101	for (it = rays.begin(); it != it_end; ++ it)
2102	{
2103	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2104	(it)->mRay->Extrap((it)->mMaxT));
2105	}
2106
2107	return len;
2108	}
2109
2110
2111	int BspTree::SplitRays(const Plane3 &plane,
2112	BoundedRayContainer &rays,
2113	BoundedRayContainer &frontRays,
2114	BoundedRayContainer &backRays)
2115	{
2116	int splits = 0;
2117
2118	while (!rays.empty())
2119	{
2120	BoundedRay *bRay = rays.back();
2121	Ray *ray = bRay->mRay;
2122	float minT = bRay->mMinT;
2123	float maxT = bRay->mMaxT;
2124
2125	rays.pop_back();
2126
2127	Vector3 entP, extP;
2128
2129	const int cf =
2130	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2131
2132	// set id to ray classification
2133	ray->SetId(cf);
2134
2135	switch (cf)
2136	{
2137	case Ray::COINCIDENT: // TODO: should really discard ray?
2138	frontRays.push_back(bRay);
2139	//DEL_PTR(bRay);
2140	break;
2141	case Ray::BACK:
2142	backRays.push_back(bRay);
2143	break;
2144	case Ray::FRONT:
2145	frontRays.push_back(bRay);
2146	break;
2147	case Ray::FRONT_BACK:
2148	{
2149	// find intersection of ray segment with plane
2150	const float t = plane.FindT(ray->GetLoc(), extP);
2151
2152	const float newT = t * maxT;
2153
2154	frontRays.push_back(new BoundedRay(ray, minT, newT));
2155	backRays.push_back(new BoundedRay(ray, newT, maxT));
2156
2157	DEL_PTR(bRay);
2158	}
2159	break;
2160	case Ray::BACK_FRONT:
2161	{
2162	// find intersection of ray segment with plane
2163	const float t = plane.FindT(ray->GetLoc(), extP);
2164	const float newT = t * bRay->mMaxT;
2165
2166	backRays.push_back(new BoundedRay(ray, minT, newT));
2167	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2168
2169	DEL_PTR(bRay);
2170
2171	++ splits;
2172	}
2173	break;
2174	default:
2175	Debug << "Should not come here 4" << endl;
2176	break;
2177	}
2178	}
2179
2180	return splits;
2181	}
2182
2183	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2184	{
2185	BspNode *lastNode;
2186	do
2187	{
2188	lastNode = n;
2189
2190	// want to get planes defining geometry of this node => don't take
2191	// split plane of node itself
2192	n = n->GetParent();
2193
2194	if (n)
2195	{
2196	BspInterior interior = dynamic_cast<BspInterior >(n);
2197	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2198
2199	if (interior->GetFront() != lastNode)
2200	halfSpace.ReverseOrientation();
2201
2202	halfSpaces.push_back(halfSpace);
2203	}
2204	}
2205	while (n);
2206	}
2207
2208	void BspTree::ConstructGeometry(BspViewCell *vc, BspNodeGeometry &geom) const
2209	{
2210	vector<BspLeaf *> leaves = vc->mLeaves;
2211
2212	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2213
2214	for (it = leaves.begin(); it != it_end; ++ it)
2215	ConstructGeometry(*it, geom);
2216	}
2217
2218
2219	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2220	{
2221	vector<Plane3> halfSpaces;
2222	ExtractHalfSpaces(n, halfSpaces);
2223
2224	PolygonContainer candidates;
2225
2226	// bounded planes are added to the polygons (reverse polygons
2227	// as they have to be outfacing
2228	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2229	{
2230	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2231
2232	if (p->Valid(mEpsilon))
2233	{
2234	candidates.push_back(p->CreateReversePolygon());
2235	DEL_PTR(p);
2236	}
2237	}
2238
2239	// add faces of bounding box (also could be faces of the cell)
2240	for (int i = 0; i < 6; ++ i)
2241	{
2242	VertexContainer vertices;
2243
2244	for (int j = 0; j < 4; ++ j)
2245	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2246
2247	candidates.push_back(new Polygon3(vertices));
2248	}
2249
2250	for (int i = 0; i < (int)candidates.size(); ++ i)
2251	{
2252	// polygon is split by all other planes
2253	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2254	{
2255	if (i == j) // polygon and plane are coincident
2256	continue;
2257
2258	VertexContainer splitPts;
2259	Polygon3 frontPoly, backPoly;
2260
2261	const int cf = candidates[i]->
2262	ClassifyPlane(halfSpaces[j], mEpsilon);
2263
2264	switch (cf)
2265	{
2266	case Polygon3::SPLIT:
2267	frontPoly = new Polygon3();
2268	backPoly = new Polygon3();
2269
2270	candidates[i]->Split(halfSpaces[j],
2271	*frontPoly,
2272	*backPoly,
2273	mEpsilon);
2274
2275	DEL_PTR(candidates[i]);
2276
2277	if (frontPoly->Valid(mEpsilon))
2278	candidates[i] = frontPoly;
2279	else
2280	DEL_PTR(frontPoly);
2281
2282	DEL_PTR(backPoly);
2283	break;
2284	case Polygon3::BACK_SIDE:
2285	DEL_PTR(candidates[i]);
2286	break;
2287	// just take polygon as it is
2288	case Polygon3::FRONT_SIDE:
2289	case Polygon3::COINCIDENT:
2290	default:
2291	break;
2292	}
2293	}
2294
2295	if (candidates[i])
2296	geom.mPolys.push_back(candidates[i]);
2297	}
2298	}
2299
2300
2301	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2302	const bool onlyUnmailed) const
2303	{
2304	BspNodeGeometry geom;
2305	ConstructGeometry(n, geom);
2306
2307	stack<BspNode *> nodeStack;
2308	nodeStack.push(mRoot);
2309
2310	// planes needed to verify that we found neighbor leaf.
2311	vector<Plane3> halfSpaces;
2312	ExtractHalfSpaces(n, halfSpaces);
2313
2314	while (!nodeStack.empty())
2315	{
2316	BspNode *node = nodeStack.top();
2317	nodeStack.pop();
2318
2319	if (node->IsLeaf())
2320	{
2321	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2322	{
2323	// test all planes of current node if neighbour
2324	// candidate really is neighbour
2325	BspNodeGeometry candidateGeom;
2326	ConstructGeometry(node, candidateGeom);
2327
2328	bool isAdjacent = true;
2329	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2330	{
2331	const int cf =
2332	Polygon3::ClassifyPlane(candidateGeom.mPolys,
2333	halfSpaces[i],
2334	mEpsilon);
2335
2336	if (cf == Polygon3::BACK_SIDE)
2337	isAdjacent = false;
2338	}
2339
2340	if (isAdjacent)
2341	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2342	}
2343	}
2344	else
2345	{
2346	BspInterior interior = dynamic_cast<BspInterior >(node);
2347
2348	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2349	interior->mPlane,
2350	mEpsilon);
2351
2352	if (cf == Polygon3::FRONT_SIDE)
2353	nodeStack.push(interior->GetFront());
2354	else
2355	if (cf == Polygon3::BACK_SIDE)
2356	nodeStack.push(interior->GetBack());
2357	else
2358	{
2359	// random decision
2360	nodeStack.push(interior->GetBack());
2361	nodeStack.push(interior->GetFront());
2362	}
2363	}
2364	}
2365
2366	return (int)neighbors.size();
2367	}
2368
2369
2370	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2371	{
2372	stack<BspNode *> nodeStack;
2373	nodeStack.push(mRoot);
2374
2375	int mask = rand();
2376
2377	while (!nodeStack.empty())
2378	{
2379	BspNode *node = nodeStack.top();
2380	nodeStack.pop();
2381
2382	if (node->IsLeaf())
2383	{
2384	return dynamic_cast<BspLeaf *>(node);
2385	}
2386	else
2387	{
2388	BspInterior interior = dynamic_cast<BspInterior >(node);
2389	BspNode *next;
2390
2391	BspNodeGeometry geom;
2392	// todo: not very efficient: constructs full cell everytime
2393	ConstructGeometry(interior, geom);
2394
2395	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2396	halfspace,
2397	mEpsilon);
2398
2399	if (cf == Polygon3::BACK_SIDE)
2400	next = interior->GetFront();
2401	else
2402	if (cf == Polygon3::FRONT_SIDE)
2403	next = interior->GetFront();
2404	else
2405	{
2406	// random decision
2407	if (mask & 1)
2408	next = interior->GetBack();
2409	else
2410	next = interior->GetFront();
2411	mask = mask >> 1;
2412	}
2413
2414	nodeStack.push(next);
2415	}
2416	}
2417
2418	return NULL;
2419	}
2420
2421	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2422	{
2423	stack<BspNode *> nodeStack;
2424
2425	nodeStack.push(mRoot);
2426
2427	int mask = rand();
2428
2429	while (!nodeStack.empty())
2430	{
2431	BspNode *node = nodeStack.top();
2432	nodeStack.pop();
2433
2434	if (node->IsLeaf())
2435	{
2436	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2437	return dynamic_cast<BspLeaf *>(node);
2438	}
2439	else
2440	{
2441	BspInterior interior = dynamic_cast<BspInterior >(node);
2442
2443	// random decision
2444	if (mask & 1)
2445	nodeStack.push(interior->GetBack());
2446	else
2447	nodeStack.push(interior->GetFront());
2448
2449	mask = mask >> 1;
2450	}
2451	}
2452
2453	return NULL;
2454	}
2455
2456	void BspTree::AddToPvs(BspLeaf *leaf,
2457	const BoundedRayContainer &rays,
2458	int &sampleContributions,
2459	int &contributingSamples)
2460	{
2461	sampleContributions = 0;
2462	contributingSamples = 0;
2463
2464	BoundedRayContainer::const_iterator it, it_end = rays.end();
2465
2466	ViewCell *vc = leaf->GetViewCell();
2467
2468	// add contributions from samples to the PVS
2469	for (it = rays.begin(); it != it_end; ++ it)
2470	{
2471	int contribution = 0;
2472	Ray ray = (it)->mRay;
2473	float relContribution;
2474	if (!ray->intersections.empty())
2475	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2476	1.0f,
2477	relContribution);
2478
2479	if (ray->sourceObject.mObject)
2480	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2481	1.0f,
2482	relContribution);
2483
2484	if (contribution)
2485	{
2486	sampleContributions += contribution;
2487	++ contributingSamples;
2488	}
2489
2490	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2491	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2492	}
2493	}
2494
2495	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2496	{
2497	int pvsSize = 0;
2498
2499	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2500
2501	Intersectable::NewMail();
2502
2503	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2504	{
2505	Ray ray = (rit)->mRay;
2506
2507	if (!ray->intersections.empty())
2508	{
2509	if (!ray->intersections[0].mObject->Mailed())
2510	{
2511	ray->intersections[0].mObject->Mail();
2512	++ pvsSize;
2513	}
2514	}
2515	if (ray->sourceObject.mObject)
2516	{
2517	if (!ray->sourceObject.mObject->Mailed())
2518	{
2519	ray->sourceObject.mObject->Mail();
2520	++ pvsSize;
2521	}
2522	}
2523	}
2524
2525	return pvsSize;
2526	}
2527
2528	float BspTree::GetEpsilon() const
2529	{
2530	return mEpsilon;
2531	}
2532
2533
2534	/*************************************************************/
2535	/* BspNodeGeometry Implementation */
2536	/*************************************************************/
2537
2538
2539	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2540	{
2541	mPolys.reserve(rhs.mPolys.size());
2542
2543	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2544	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2545	{
2546	Polygon3 poly = it;
2547	mPolys.push_back(new Polygon3(*poly));
2548	}
2549	}
2550
2551
2552	BspNodeGeometry::~BspNodeGeometry()
2553	{
2554	CLEAR_CONTAINER(mPolys);
2555	}
2556
2557
2558	float BspNodeGeometry::GetArea() const
2559	{
2560	return Polygon3::GetArea(mPolys);
2561	}
2562
2563
2564	float BspNodeGeometry::GetVolume() const
2565	{
2566	//-- compute volume using tetrahedralization of the geometry
2567	// and adding the volume of the single tetrahedrons
2568	float volume = 0;
2569	const float f = 1.0f / 6.0f;
2570
2571	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2572
2573	// note: can take arbitrary point, e.g., the origin. However,
2574	// center of mass prevents precision errors
2575	const Vector3 center = CenterOfMass();
2576
2577	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2578	{
2579	Polygon3 poly = pit;
2580	const Vector3 v0 = poly->mVertices[0] - center;
2581
2582	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2583	{
2584	const Vector3 v1 = poly->mVertices[i] - center;
2585	const Vector3 v2 = poly->mVertices[i + 1] - center;
2586
2587	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2588	}
2589	}
2590
2591	return volume;
2592	}
2593
2594
2595	Vector3 BspNodeGeometry::CenterOfMass() const
2596	{
2597	int n = 0;
2598
2599	Vector3 center(0,0,0);
2600
2601	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2602
2603	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2604	{
2605	Polygon3 poly = pit;
2606
2607	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2608
2609	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2610	{
2611	center += *vit;
2612	++ n;
2613	}
2614	}
2615
2616	return center / (float)n;
2617	}
2618
2619
2620	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2621	{
2622	PolygonContainer::const_iterator it, it_end = mPolys.end();
2623
2624	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2625	{
2626	(*it)->AddToMesh(mesh);
2627	}
2628	}
2629
2630
2631	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2632	BspNodeGeometry &back,
2633	const Plane3 &splitPlane,
2634	const AxisAlignedBox3 &box,
2635	const float epsilon) const
2636	{
2637	// get cross section of new polygon
2638	Polygon3 *planePoly = box.CrossSection(splitPlane);
2639
2640	// split polygon with all other polygons
2641	planePoly = SplitPolygon(planePoly, epsilon);
2642
2643	//-- new polygon splits all other polygons
2644	for (int i = 0; i < (int)mPolys.size(); ++ i)
2645	{
2646	/// don't use epsilon here to get exact split planes
2647	const int cf =
2648	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2649
2650	switch (cf)
2651	{
2652	case Polygon3::SPLIT:
2653	{
2654	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2655
2656	Polygon3 *frontPoly = new Polygon3();
2657	Polygon3 *backPoly = new Polygon3();
2658
2659	poly->Split(splitPlane,
2660	*frontPoly,
2661	*backPoly,
2662	epsilon);
2663
2664	DEL_PTR(poly);
2665
2666	if (frontPoly->Valid(epsilon))
2667	front.mPolys.push_back(frontPoly);
2668	else
2669	DEL_PTR(frontPoly);
2670
2671	if (backPoly->Valid(epsilon))
2672	back.mPolys.push_back(backPoly);
2673	else
2674	DEL_PTR(backPoly);
2675	}
2676
2677	break;
2678	case Polygon3::BACK_SIDE:
2679	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2680	break;
2681	case Polygon3::FRONT_SIDE:
2682	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2683	break;
2684	case Polygon3::COINCIDENT:
2685	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2686	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2687	break;
2688	default:
2689	break;
2690	}
2691	}
2692
2693	//-- finally add the new polygon to the child node geometries
2694	if (planePoly)
2695	{
2696	// add polygon with normal pointing into positive half space to back cell
2697	back.mPolys.push_back(planePoly);
2698	// add polygon with reverse orientation to front cell
2699	front.mPolys.push_back(planePoly->CreateReversePolygon());
2700	}
2701
2702	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2703	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2704	}
2705
2706
2707	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2708	const float epsilon) const
2709	{
2710	if (!planePoly->Valid(epsilon))
2711	DEL_PTR(planePoly);
2712
2713	// polygon is split by all other planes
2714	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2715	{
2716	Plane3 plane = mPolys[i]->GetSupportingPlane();
2717
2718	/// don't use epsilon here to get exact split planes
2719	const int cf =
2720	planePoly->ClassifyPlane(plane, Limits::Small);
2721
2722	// split new polygon with all previous planes
2723	switch (cf)
2724	{
2725	case Polygon3::SPLIT:
2726	{
2727	Polygon3 *frontPoly = new Polygon3();
2728	Polygon3 *backPoly = new Polygon3();
2729
2730	planePoly->Split(plane,
2731	*frontPoly,
2732	*backPoly,
2733	epsilon);
2734
2735	// don't need anymore
2736	DEL_PTR(planePoly);
2737	DEL_PTR(frontPoly);
2738
2739	// back polygon is belonging to geometry
2740	if (backPoly->Valid(epsilon))
2741	planePoly = backPoly;
2742	else
2743	DEL_PTR(backPoly);
2744	}
2745	break;
2746	case Polygon3::FRONT_SIDE:
2747	DEL_PTR(planePoly);
2748	break;
2749	// polygon is taken as it is
2750	case Polygon3::BACK_SIDE:
2751	case Polygon3::COINCIDENT:
2752	default:
2753	break;
2754	}
2755	}
2756
2757	return planePoly;
2758	}
2759
2760
2761	ViewCell *
2762	BspTree::GetViewCell(const Vector3 &point)
2763	{
2764	if (mRoot == NULL)
2765	return NULL;
2766
2767
2768	stack<BspNode *> nodeStack;
2769	nodeStack.push(mRoot);
2770
2771	ViewCell *viewcell = NULL;
2772
2773	while (!nodeStack.empty()) {
2774	BspNode *node = nodeStack.top();
2775	nodeStack.pop();
2776
2777	if (node->IsLeaf()) {
2778	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
2779	break;
2780	} else {
2781
2782	BspInterior interior = dynamic_cast<BspInterior >(node);
2783
2784	// random decision
2785	if (interior->GetPlane().Side(point) < 0)
2786	nodeStack.push(interior->GetBack());
2787	else
2788	nodeStack.push(interior->GetFront());
2789	}
2790	}
2791
2792	return viewcell;
2793	}
2794
2795	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
2796	{
2797	Polygon3::IncludeInBox(mPolys, box);
2798	}

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