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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 582

Revision 582, 69.1 KB checked in by mattausch, 18 years ago (diff)
fixed bug in mergueue to find root of merge and sort out doube view cells

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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->mLeaf = 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
1033	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1034	const int axis,
1035	vector<SortableEntry> &splitCandidates) const
1036	{
1037	splitCandidates.clear();
1038
1039	int requestedSize = 2 * (int)polys.size();
1040	// creates a sorted split candidates array
1041	splitCandidates.reserve(requestedSize);
1042
1043	PolygonContainer::const_iterator it, it_end = polys.end();
1044
1045	AxisAlignedBox3 box;
1046
1047	// insert all queries
1048	for(it = polys.begin(); it != it_end; ++ it)
1049	{
1050	box.Initialize();
1051	box.Include((it));
1052
1053	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1054	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1055	}
1056
1057	stable_sort(splitCandidates.begin(), splitCandidates.end());
1058	}
1059
1060
1061	float BspTree::BestCostRatio(const PolygonContainer &polys,
1062	const AxisAlignedBox3 &box,
1063	const int axis,
1064	float &position,
1065	int &objectsBack,
1066	int &objectsFront) const
1067	{
1068	vector<SortableEntry> splitCandidates;
1069
1070	SortSplitCandidates(polys, axis, splitCandidates);
1071
1072	// go through the lists, count the number of objects left and right
1073	// and evaluate the following cost funcion:
1074	// C = ct_div_ci + (ol + or)/queries
1075
1076	int objectsLeft = 0, objectsRight = (int)polys.size();
1077
1078	float minBox = box.Min(axis);
1079	float maxBox = box.Max(axis);
1080	float boxArea = box.SurfaceArea();
1081
1082	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1083	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1084
1085	float minSum = 1e20f;
1086	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1087
1088	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1089	{
1090	switch ((*ci).type)
1091	{
1092	case SortableEntry::POLY_MIN:
1093	++ objectsLeft;
1094	break;
1095	case SortableEntry::POLY_MAX:
1096	-- objectsRight;
1097	break;
1098	default:
1099	break;
1100	}
1101
1102	if ((ci).value > minBand && (ci).value < maxBand)
1103	{
1104	AxisAlignedBox3 lbox = box;
1105	AxisAlignedBox3 rbox = box;
1106	lbox.SetMax(axis, (*ci).value);
1107	rbox.SetMin(axis, (*ci).value);
1108
1109	const float sum = objectsLeft * lbox.SurfaceArea() +
1110	objectsRight * rbox.SurfaceArea();
1111
1112	if (sum < minSum)
1113	{
1114	minSum = sum;
1115	position = (*ci).value;
1116
1117	objectsBack = objectsLeft;
1118	objectsFront = objectsRight;
1119	}
1120	}
1121	}
1122
1123	const float oldCost = (float)polys.size();
1124	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1125	const float ratio = newCost / oldCost;
1126
1127
1128	#if 0
1129	Debug << "====================" << endl;
1130	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1131	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1132	#endif
1133	return ratio;
1134	}
1135
1136	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1137	const PolygonContainer &polys) const
1138	{
1139	AxisAlignedBox3 box;
1140	box.Initialize();
1141
1142	// create bounding box of region
1143	Polygon3::IncludeInBox(polys, box);
1144
1145	int objectsBack = 0, objectsFront = 0;
1146	int axis = 0;
1147	float costRatio = MAX_FLOAT;
1148	Vector3 position;
1149
1150	//-- area subdivision
1151	for (int i = 0; i < 3; ++ i)
1152	{
1153	float p = 0;
1154	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1155
1156	if (r < costRatio)
1157	{
1158	costRatio = r;
1159	axis = i;
1160	position = p;
1161	}
1162	}
1163
1164	if (costRatio >= mMaxCostRatio)
1165	return false;
1166
1167	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1168	plane = Plane3(norm, position);
1169
1170	return true;
1171	}
1172
1173
1174	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1175	{
1176	if (data.mPolygons->empty() && data.mRays->empty())
1177	{
1178	Debug << "Warning: No autopartition polygon candidate available\n";
1179
1180	// return axis aligned split
1181	AxisAlignedBox3 box;
1182	box.Initialize();
1183
1184	// create bounding box of region
1185	Polygon3::IncludeInBox(*data.mPolygons, box);
1186
1187	const int axis = box.Size().DrivingAxis();
1188	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1189
1190	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1191	return Plane3(norm, position);
1192	}
1193
1194	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1195	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1196	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1197	((mTermMinObjectsForAxisAligned < 0) \|\|
1198	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1199	{
1200	Plane3 plane;
1201	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1202	return plane;
1203	}
1204
1205	// simplest strategy: just take next polygon
1206	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1207	{
1208	if (!data.mPolygons->empty())
1209	{
1210	Polygon3 *nextPoly =
1211	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1212	return nextPoly->GetSupportingPlane();
1213	}
1214	else
1215	{
1216	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1217	BoundedRay bRay = (data.mRays)[candidateIdx];
1218
1219	Ray *ray = bRay->mRay;
1220
1221	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1222	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1223
1224	const Vector3 pt = (maxPt + minPt) * 0.5;
1225
1226	const Vector3 normal = ray->GetDir();
1227
1228	return Plane3(normal, pt);
1229	}
1230
1231	return Plane3();
1232	}
1233
1234	// use heuristics to find appropriate plane
1235	return SelectPlaneHeuristics(leaf, data);
1236	}
1237
1238
1239	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1240	{
1241	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1242	BoundedRay *bRay = rays[candidateIdx];
1243	Ray *ray = bRay->mRay;
1244
1245	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1246	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1247
1248	const Vector3 pt = (maxPt + minPt) * 0.5;
1249
1250	const Vector3 normal = ray->GetDir();
1251
1252	return Plane3(normal, pt);
1253	}
1254
1255	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1256	{
1257	Vector3 pt[3];
1258	int idx[3];
1259	int cmaxT = 0;
1260	int cminT = 0;
1261	bool chooseMin = false;
1262
1263	for (int j = 0; j < 3; j ++)
1264	{
1265	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1266
1267	if (idx[j] >= (int)rays.size())
1268	{
1269	idx[j] -= (int)rays.size();
1270	chooseMin = (cminT < 2);
1271	}
1272	else
1273	chooseMin = (cmaxT < 2);
1274
1275	BoundedRay *bRay = rays[idx[j]];
1276	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1277	bRay->mRay->Extrap(bRay->mMaxT);
1278	}
1279
1280	return Plane3(pt[0], pt[1], pt[2]);
1281	}
1282
1283	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1284	{
1285	Vector3 pt[3];
1286
1287	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1288	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1289
1290	// check if rays different
1291	if (idx1 == idx2)
1292	idx2 = (idx2 + 1) % (int)rays.size();
1293
1294	const BoundedRay *ray1 = rays[idx1];
1295	const BoundedRay *ray2 = rays[idx2];
1296
1297	// normal vector of the plane parallel to both lines
1298	const Vector3 norm =
1299	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1300
1301	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1302	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1303
1304	// vector from line 1 to line 2
1305	const Vector3 vd = orig1 - orig2;
1306
1307	// project vector on normal to get distance
1308	const float dist = DotProd(vd, norm);
1309
1310	// point on plane lies halfway between the two planes
1311	const Vector3 planePt = orig1 + norm * dist * 0.5;
1312
1313	return Plane3(norm, planePt);
1314	}
1315
1316
1317	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1318	{
1319	float lowestCost = MAX_FLOAT;
1320	Plane3 bestPlane;
1321	// intermediate plane
1322	Plane3 plane;
1323
1324	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1325	int maxIdx = (int)data.mPolygons->size();
1326
1327	for (int i = 0; i < limit; ++ i)
1328	{
1329	// assure that no index is taken twice
1330	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1331	//Debug << "current Idx: " << maxIdx << " cand idx " << candidateIdx << endl;
1332
1333	Polygon3 poly = (data.mPolygons)[candidateIdx];
1334
1335	// swap candidate to the end to avoid testing same plane
1336	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1337
1338	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1339
1340	// evaluate current candidate
1341	const float candidateCost =
1342	SplitPlaneCost(poly->GetSupportingPlane(), data);
1343
1344	if (candidateCost < lowestCost)
1345	{
1346	bestPlane = poly->GetSupportingPlane();
1347	lowestCost = candidateCost;
1348	}
1349	}
1350
1351	//-- choose candidate planes extracted from rays
1352	for (int i = 0; i < mMaxRayCandidates; ++ i)
1353	{
1354	plane = ChooseCandidatePlane3(*data.mRays);
1355	const float candidateCost = SplitPlaneCost(plane, data);
1356
1357	if (candidateCost < lowestCost)
1358	{
1359	bestPlane = plane;
1360	lowestCost = candidateCost;
1361	}
1362	}
1363
1364	#ifdef _DEBUG
1365	Debug << "plane lowest cost: " << lowestCost << endl;
1366	#endif
1367
1368	return bestPlane;
1369	}
1370
1371
1372	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1373	const PolygonContainer &polys) const
1374	{
1375	float val = 0;
1376
1377	float sumBalancedPolys = 0;
1378	float sumSplits = 0;
1379	float sumPolyArea = 0;
1380	float sumBalancedViewCells = 0;
1381	float sumBlockedRays = 0;
1382	float totalBlockedRays = 0;
1383	//float totalArea = 0;
1384	int totalViewCells = 0;
1385
1386	// need three unique ids for each type of view cell
1387	// for balanced view cells criterium
1388	ViewCell::NewMail();
1389	const int backId = ViewCell::sMailId;
1390	ViewCell::NewMail();
1391	const int frontId = ViewCell::sMailId;
1392	ViewCell::NewMail();
1393	const int frontAndBackId = ViewCell::sMailId;
1394
1395	bool useRand;;
1396	int limit;
1397
1398	// choose test polyongs randomly if over threshold
1399	if ((int)polys.size() > mMaxTests)
1400	{
1401	useRand = true;
1402	limit = mMaxTests;
1403	}
1404	else
1405	{
1406	useRand = false;
1407	limit = (int)polys.size();
1408	}
1409
1410	for (int i = 0; i < limit; ++ i)
1411	{
1412	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1413
1414	Polygon3 *poly = polys[testIdx];
1415
1416	const int classification =
1417	poly->ClassifyPlane(candidatePlane, mEpsilon);
1418
1419	if (mSplitPlaneStrategy & BALANCED_POLYS)
1420	sumBalancedPolys += sBalancedPolysTable[classification];
1421
1422	if (mSplitPlaneStrategy & LEAST_SPLITS)
1423	sumSplits += sLeastPolySplitsTable[classification];
1424
1425	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1426	{
1427	if (classification == Polygon3::COINCIDENT)
1428	sumPolyArea += poly->GetArea();
1429	//totalArea += area;
1430	}
1431
1432	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1433	{
1434	const float blockedRays = (float)poly->mPiercingRays.size();
1435
1436	if (classification == Polygon3::COINCIDENT)
1437	sumBlockedRays += blockedRays;
1438
1439	totalBlockedRays += blockedRays;
1440	}
1441
1442	// assign view cells to back or front according to classificaion
1443	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1444	{
1445	MeshInstance *viewCell = poly->mParent;
1446
1447	// assure that we only count a view cell
1448	// once for the front and once for the back side of the plane
1449	if (classification == Polygon3::FRONT_SIDE)
1450	{
1451	if ((viewCell->mMailbox != frontId) &&
1452	(viewCell->mMailbox != frontAndBackId))
1453	{
1454	sumBalancedViewCells += 1.0;
1455
1456	if (viewCell->mMailbox != backId)
1457	viewCell->mMailbox = frontId;
1458	else
1459	viewCell->mMailbox = frontAndBackId;
1460
1461	++ totalViewCells;
1462	}
1463	}
1464	else if (classification == Polygon3::BACK_SIDE)
1465	{
1466	if ((viewCell->mMailbox != backId) &&
1467	(viewCell->mMailbox != frontAndBackId))
1468	{
1469	sumBalancedViewCells -= 1.0;
1470
1471	if (viewCell->mMailbox != frontId)
1472	viewCell->mMailbox = backId;
1473	else
1474	viewCell->mMailbox = frontAndBackId;
1475
1476	++ totalViewCells;
1477	}
1478	}
1479	}
1480	}
1481
1482	const float polysSize = (float)polys.size() + Limits::Small;
1483
1484	// all values should be approx. between 0 and 1 so they can be combined
1485	// and scaled with the factors according to their importance
1486	if (mSplitPlaneStrategy & BALANCED_POLYS)
1487	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1488
1489	if (mSplitPlaneStrategy & LEAST_SPLITS)
1490	val += mLeastSplitsFactor * sumSplits / polysSize;
1491
1492	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1493	// HACK: polys.size should be total area so scaling is between 0 and 1
1494	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1495
1496	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1497	if (totalBlockedRays != 0)
1498	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1499
1500	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1501	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1502	((float)totalViewCells + Limits::Small);
1503
1504	return val;
1505	}
1506
1507
1508	inline void BspTree::GenerateUniqueIdsForPvs()
1509	{
1510	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1511	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1512	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1513	}
1514
1515
1516	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1517	const BoundedRayContainer &rays,
1518	const int pvs,
1519	const float area,
1520	const BspNodeGeometry &cell) const
1521	{
1522	float val = 0;
1523
1524	float sumBalancedRays = 0;
1525	float sumRaySplits = 0;
1526
1527	int frontPvs = 0;
1528	int backPvs = 0;
1529
1530	// probability that view point lies in child
1531	float pOverall = 0;
1532	float pFront = 0;
1533	float pBack = 0;
1534
1535	const bool pvsUseLen = false;
1536
1537	if (mSplitPlaneStrategy & PVS)
1538	{
1539	// create unique ids for pvs heuristics
1540	GenerateUniqueIdsForPvs();
1541
1542	if (mUseAreaForPvs) // use front and back cell areas to approximate volume
1543	{
1544	// construct child geometry with regard to the candidate split plane
1545	BspNodeGeometry frontCell;
1546	BspNodeGeometry backCell;
1547
1548	cell.SplitGeometry(frontCell,
1549	backCell,
1550	candidatePlane,
1551	mBox,
1552	mEpsilon);
1553
1554	pFront = frontCell.GetArea();
1555	pBack = backCell.GetArea();
1556
1557	pOverall = area;
1558	}
1559	}
1560
1561	bool useRand;
1562	int limit;
1563
1564	// choose test polyongs randomly if over threshold
1565	if ((int)rays.size() > mMaxTests)
1566	{
1567	useRand = true;
1568	limit = mMaxTests;
1569	}
1570	else
1571	{
1572	useRand = false;
1573	limit = (int)rays.size();
1574	}
1575
1576	for (int i = 0; i < limit; ++ i)
1577	{
1578	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1579
1580	BoundedRay *bRay = rays[testIdx];
1581
1582	Ray *ray = bRay->mRay;
1583	const float minT = bRay->mMinT;
1584	const float maxT = bRay->mMaxT;
1585
1586	Vector3 entP, extP;
1587
1588	const int cf =
1589	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1590
1591	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1592	{
1593	sumBalancedRays += sBalancedRaysTable[cf];
1594	}
1595
1596	if (mSplitPlaneStrategy & BALANCED_RAYS)
1597	{
1598	sumRaySplits += sLeastRaySplitsTable[cf];
1599	}
1600
1601	if (mSplitPlaneStrategy & PVS)
1602	{
1603	// in case the ray intersects an object
1604	// assure that we only count the object
1605	// once for the front and once for the back side of the plane
1606
1607	// add the termination object
1608	if (!ray->intersections.empty())
1609	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1610
1611	// add the source object
1612	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1613
1614	if (mUseAreaForPvs)
1615	{
1616	float len = 1;
1617
1618	if (pvsUseLen)
1619	len = SqrDistance(entP, extP);
1620
1621	// use length of rays to approximate volume
1622	if (Ray::BACK && Ray::COINCIDENT)
1623	pBack += len;
1624	if (Ray::FRONT && Ray::COINCIDENT)
1625	pFront += len;
1626	if (Ray::FRONT_BACK \|\| Ray::BACK_FRONT)
1627	{
1628	if (pvsUseLen)
1629	{
1630	const Vector3 extp = ray->Extrap(maxT);
1631	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1632
1633	const float newT = t * maxT;
1634	const float newLen = SqrDistance(ray->Extrap(newT), extp);
1635
1636	if (Ray::FRONT_BACK)
1637	{
1638	pFront += len - newLen;
1639	pBack += newLen;
1640	}
1641	else
1642	{
1643	pBack += len - newLen;
1644	pFront += newLen;
1645	}
1646	}
1647	else
1648	{
1649	++ pFront;
1650	++ pBack;
1651	}
1652	}
1653	}
1654	}
1655	}
1656
1657	const float raysSize = (float)rays.size() + Limits::Small;
1658
1659	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1660	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1661
1662	if (mSplitPlaneStrategy & BALANCED_RAYS)
1663	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1664
1665	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1666
1667	if (mSplitPlaneStrategy & PVS)
1668	{
1669	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1670
1671	// give penalty to unbalanced split
1672	if (0)
1673	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1674	(pFront < (pBack * 0.2 + Limits::Small)))
1675	val += 0.5;
1676	}
1677
1678
1679	#ifdef _DEBUG
1680	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1681	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1682	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1683	#endif
1684
1685	return val;
1686	}
1687
1688	void BspTree::AddObjToPvs(Intersectable *obj,
1689	const int cf,
1690	int &frontPvs,
1691	int &backPvs) const
1692	{
1693	if (!obj)
1694	return;
1695	// TODO: does this really belong to no pvs?
1696	//if (cf == Ray::COINCIDENT) return;
1697
1698	// object belongs to both PVS
1699	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1700	(cf == Ray::BACK_FRONT) \|\|
1701	(cf == Ray::COINCIDENT);
1702
1703	if ((cf == Ray::FRONT) \|\| bothSides)
1704	{
1705	if ((obj->mMailbox != sFrontId) &&
1706	(obj->mMailbox != sFrontAndBackId))
1707	{
1708	++ frontPvs;
1709
1710	if (obj->mMailbox == sBackId)
1711	obj->mMailbox = sFrontAndBackId;
1712	else
1713	obj->mMailbox = sFrontId;
1714	}
1715	}
1716
1717	if ((cf == Ray::BACK) \|\| bothSides)
1718	{
1719	if ((obj->mMailbox != sBackId) &&
1720	(obj->mMailbox != sFrontAndBackId))
1721	{
1722	++ backPvs;
1723
1724	if (obj->mMailbox == sFrontId)
1725	obj->mMailbox = sFrontAndBackId;
1726	else
1727	obj->mMailbox = sBackId;
1728	}
1729	}
1730	}
1731
1732	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1733	BspTraversalData &data) const
1734	{
1735	float val = 0;
1736
1737	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1738	{
1739	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1740	// we put a penalty on the dot product between the "tiny" vertical axis
1741	// and the split plane axis
1742	val += mVerticalSplitsFactor *
1743	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1744	}
1745
1746	// the following criteria loop over all polygons to find the cost value
1747	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1748	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1749	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1750	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1751	(mSplitPlaneStrategy & BLOCKED_RAYS))
1752	{
1753	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1754	}
1755
1756	// the following criteria loop over all rays to find the cost value
1757	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1758	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1759	(mSplitPlaneStrategy & PVS))
1760	{
1761	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1762	data.mArea, *data.mGeometry);
1763	}
1764
1765	// return linear combination of the sums
1766	return val;
1767	}
1768
1769	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1770	{
1771	stack<BspNode *> nodeStack;
1772	nodeStack.push(mRoot);
1773
1774	while (!nodeStack.empty())
1775	{
1776	BspNode *node = nodeStack.top();
1777
1778	nodeStack.pop();
1779
1780	if (node->IsLeaf())
1781	{
1782	BspLeaf leaf = (BspLeaf )node;
1783	leaves.push_back(leaf);
1784	}
1785	else
1786	{
1787	BspInterior interior = dynamic_cast<BspInterior >(node);
1788
1789	nodeStack.push(interior->GetBack());
1790	nodeStack.push(interior->GetFront());
1791	}
1792	}
1793	}
1794
1795
1796	AxisAlignedBox3 BspTree::GetBoundingBox() const
1797	{
1798	return mBox;
1799	}
1800
1801
1802	BspNode *BspTree::GetRoot() const
1803	{
1804	return mRoot;
1805	}
1806
1807	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1808	{
1809	// the node became a leaf -> evaluate stats for leafs
1810	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1811
1812	// store maximal and minimal depth
1813	if (data.mDepth > mStat.maxDepth)
1814	mStat.maxDepth = data.mDepth;
1815
1816	if (data.mDepth < mStat.minDepth)
1817	mStat.minDepth = data.mDepth;
1818
1819	// accumulate depth to compute average depth
1820	mStat.accumDepth += data.mDepth;
1821	// accumulate rays to compute rays / leaf
1822	mStat.accumRays += (int)data.mRays->size();
1823
1824	if (data.mDepth >= mTermMaxDepth)
1825	++ mStat.maxDepthNodes;
1826
1827	if (data.mPvs < mTermMinPvs)
1828	++ mStat.minPvsNodes;
1829
1830	if ((int)data.mRays->size() < mTermMinRays)
1831	++ mStat.minRaysNodes;
1832
1833	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1834	++ mStat.maxRayContribNodes;
1835
1836	if (data.mGeometry->GetArea() <= mTermMinArea)
1837	++ mStat.minProbabilityNodes;
1838
1839	#ifdef _DEBUG
1840	Debug << "BSP stats: "
1841	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1842	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1843	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1844	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1845	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1846	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1847	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1848	#endif
1849	}
1850
1851	int
1852	BspTree::_CastRay(Ray &ray)
1853	{
1854	int hits = 0;
1855
1856	stack<BspRayTraversalData> tStack;
1857
1858	float maxt, mint;
1859
1860	if (!mBox.GetRaySegment(ray, mint, maxt))
1861	return 0;
1862
1863	Intersectable::NewMail();
1864
1865	Vector3 entp = ray.Extrap(mint);
1866	Vector3 extp = ray.Extrap(maxt);
1867
1868	BspNode *node = mRoot;
1869	BspNode *farChild = NULL;
1870
1871	while (1)
1872	{
1873	if (!node->IsLeaf())
1874	{
1875	BspInterior in = dynamic_cast<BspInterior >(node);
1876
1877	Plane3 splitPlane = in->GetPlane();
1878	const int entSide = splitPlane.Side(entp);
1879	const int extSide = splitPlane.Side(extp);
1880
1881	if (entSide < 0)
1882	{
1883	node = in->GetBack();
1884
1885	if(extSide <= 0) // plane does not split ray => no far child
1886	continue;
1887
1888	farChild = in->GetFront(); // plane splits ray
1889
1890	} else if (entSide > 0)
1891	{
1892	node = in->GetFront();
1893
1894	if (extSide >= 0) // plane does not split ray => no far child
1895	continue;
1896
1897	farChild = in->GetBack(); // plane splits ray
1898	}
1899	else // ray and plane are coincident
1900	{
1901	// WHAT TO DO IN THIS CASE ?
1902	//break;
1903	node = in->GetFront();
1904	continue;
1905	}
1906
1907	// push data for far child
1908	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1909
1910	// find intersection of ray segment with plane
1911	float t;
1912	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
1913	maxt *= t;
1914
1915	} else // reached leaf => intersection with view cell
1916	{
1917	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1918
1919	if (!leaf->mViewCell->Mailed())
1920	{
1921	// ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1922	leaf->mViewCell->Mail();
1923	++ hits;
1924	}
1925
1926	//-- fetch the next far child from the stack
1927	if (tStack.empty())
1928	break;
1929
1930	entp = extp;
1931	mint = maxt; // NOTE: need this?
1932
1933	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1934	break;
1935
1936	BspRayTraversalData &s = tStack.top();
1937
1938	node = s.mNode;
1939	extp = s.mExitPoint;
1940	maxt = s.mMaxT;
1941
1942	tStack.pop();
1943	}
1944	}
1945
1946	return hits;
1947	}
1948
1949
1950	int BspTree::CastLineSegment(const Vector3 &origin,
1951	const Vector3 &termination,
1952	vector<ViewCell *> &viewcells)
1953	{
1954	int hits = 0;
1955	stack<BspRayTraversalData> tStack;
1956
1957	float mint = 0.0f, maxt = 1.0f;
1958
1959	Intersectable::NewMail();
1960
1961	Vector3 entp = origin;
1962	Vector3 extp = termination;
1963
1964	BspNode *node = mRoot;
1965	BspNode *farChild = NULL;
1966
1967	while (1)
1968	{
1969	if (!node->IsLeaf())
1970	{
1971	BspInterior in = dynamic_cast<BspInterior >(node);
1972
1973	Plane3 splitPlane = in->GetPlane();
1974
1975	const int entSide = splitPlane.Side(entp);
1976	const int extSide = splitPlane.Side(extp);
1977
1978	if (entSide < 0)
1979	{
1980	node = in->GetBack();
1981
1982	if(extSide <= 0) // plane does not split ray => no far child
1983	continue;
1984
1985	farChild = in->GetFront(); // plane splits ray
1986
1987	}
1988	else if (entSide > 0)
1989	{
1990	node = in->GetFront();
1991
1992	if (extSide >= 0) // plane does not split ray => no far child
1993	continue;
1994
1995	farChild = in->GetBack(); // plane splits ray
1996	}
1997	else // ray and plane are coincident
1998	{
1999	// WHAT TO DO IN THIS CASE ?
2000	//break;
2001	node = in->GetFront();
2002	continue;
2003	}
2004
2005	// push data for far child
2006	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2007
2008	// find intersection of ray segment with plane
2009	float t;
2010	extp = splitPlane.FindIntersection(origin, extp, &t);
2011	maxt *= t;
2012	}
2013	else
2014	{
2015	// reached leaf => intersection with view cell
2016	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2017
2018	if (!leaf->mViewCell->Mailed())
2019	{
2020	viewcells.push_back(leaf->mViewCell);
2021	leaf->mViewCell->Mail();
2022	hits++;
2023	}
2024
2025	//-- fetch the next far child from the stack
2026	if (tStack.empty())
2027	break;
2028
2029	entp = extp;
2030	mint = maxt; // NOTE: need this?
2031
2032	BspRayTraversalData &s = tStack.top();
2033
2034	node = s.mNode;
2035	extp = s.mExitPoint;
2036	maxt = s.mMaxT;
2037
2038	tStack.pop();
2039	}
2040	}
2041	return hits;
2042	}
2043
2044	bool BspTree::Export(const string filename)
2045	{
2046	Exporter *exporter = Exporter::GetExporter(filename);
2047
2048	if (exporter)
2049	{
2050	exporter->ExportBspTree(*this);
2051	return true;
2052	}
2053
2054	return false;
2055	}
2056
2057	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2058	{
2059	stack<BspNode *> nodeStack;
2060	nodeStack.push(mRoot);
2061
2062	ViewCell::NewMail();
2063
2064	while (!nodeStack.empty())
2065	{
2066	BspNode *node = nodeStack.top();
2067	nodeStack.pop();
2068
2069	if (node->IsLeaf())
2070	{
2071	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2072
2073	if (!viewCell->Mailed())
2074	{
2075	viewCell->Mail();
2076	viewCells.push_back(viewCell);
2077	}
2078	}
2079	else
2080	{
2081	BspInterior interior = dynamic_cast<BspInterior >(node);
2082
2083	nodeStack.push(interior->GetFront());
2084	nodeStack.push(interior->GetBack());
2085	}
2086	}
2087	}
2088
2089
2090	BspTreeStatistics &BspTree::GetStat()
2091	{
2092	return mStat;
2093	}
2094
2095
2096	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2097	{
2098	float len = 0;
2099
2100	BoundedRayContainer::const_iterator it, it_end = rays.end();
2101
2102	for (it = rays.begin(); it != it_end; ++ it)
2103	{
2104	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2105	(it)->mRay->Extrap((it)->mMaxT));
2106	}
2107
2108	return len;
2109	}
2110
2111
2112	int BspTree::SplitRays(const Plane3 &plane,
2113	BoundedRayContainer &rays,
2114	BoundedRayContainer &frontRays,
2115	BoundedRayContainer &backRays)
2116	{
2117	int splits = 0;
2118
2119	while (!rays.empty())
2120	{
2121	BoundedRay *bRay = rays.back();
2122	Ray *ray = bRay->mRay;
2123	float minT = bRay->mMinT;
2124	float maxT = bRay->mMaxT;
2125
2126	rays.pop_back();
2127
2128	Vector3 entP, extP;
2129
2130	const int cf =
2131	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2132
2133	// set id to ray classification
2134	ray->SetId(cf);
2135
2136	switch (cf)
2137	{
2138	case Ray::COINCIDENT: // TODO: should really discard ray?
2139	frontRays.push_back(bRay);
2140	//DEL_PTR(bRay);
2141	break;
2142	case Ray::BACK:
2143	backRays.push_back(bRay);
2144	break;
2145	case Ray::FRONT:
2146	frontRays.push_back(bRay);
2147	break;
2148	case Ray::FRONT_BACK:
2149	{
2150	// find intersection of ray segment with plane
2151	const float t = plane.FindT(ray->GetLoc(), extP);
2152
2153	const float newT = t * maxT;
2154
2155	frontRays.push_back(new BoundedRay(ray, minT, newT));
2156	backRays.push_back(new BoundedRay(ray, newT, maxT));
2157
2158	DEL_PTR(bRay);
2159	}
2160	break;
2161	case Ray::BACK_FRONT:
2162	{
2163	// find intersection of ray segment with plane
2164	const float t = plane.FindT(ray->GetLoc(), extP);
2165	const float newT = t * bRay->mMaxT;
2166
2167	backRays.push_back(new BoundedRay(ray, minT, newT));
2168	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2169
2170	DEL_PTR(bRay);
2171
2172	++ splits;
2173	}
2174	break;
2175	default:
2176	Debug << "Should not come here 4" << endl;
2177	break;
2178	}
2179	}
2180
2181	return splits;
2182	}
2183
2184	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2185	{
2186	BspNode *lastNode;
2187	do
2188	{
2189	lastNode = n;
2190
2191	// want to get planes defining geometry of this node => don't take
2192	// split plane of node itself
2193	n = n->GetParent();
2194
2195	if (n)
2196	{
2197	BspInterior interior = dynamic_cast<BspInterior >(n);
2198	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2199
2200	if (interior->GetFront() != lastNode)
2201	halfSpace.ReverseOrientation();
2202
2203	halfSpaces.push_back(halfSpace);
2204	}
2205	}
2206	while (n);
2207	}
2208
2209	void BspTree::ConstructGeometry(BspViewCell *vc, BspNodeGeometry &geom) const
2210	{
2211	// TODO
2212	/* vector<BspLeaf *> leaves = vc->mLeaves;
2213
2214	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2215
2216	for (it = leaves.begin(); it != it_end; ++ it)
2217	ConstructGeometry(it, geom);/
2218	}
2219
2220
2221	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2222	{
2223	vector<Plane3> halfSpaces;
2224	ExtractHalfSpaces(n, halfSpaces);
2225
2226	PolygonContainer candidates;
2227
2228	// bounded planes are added to the polygons (reverse polygons
2229	// as they have to be outfacing
2230	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2231	{
2232	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2233
2234	if (p->Valid(mEpsilon))
2235	{
2236	candidates.push_back(p->CreateReversePolygon());
2237	DEL_PTR(p);
2238	}
2239	}
2240
2241	// add faces of bounding box (also could be faces of the cell)
2242	for (int i = 0; i < 6; ++ i)
2243	{
2244	VertexContainer vertices;
2245
2246	for (int j = 0; j < 4; ++ j)
2247	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2248
2249	candidates.push_back(new Polygon3(vertices));
2250	}
2251
2252	for (int i = 0; i < (int)candidates.size(); ++ i)
2253	{
2254	// polygon is split by all other planes
2255	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2256	{
2257	if (i == j) // polygon and plane are coincident
2258	continue;
2259
2260	VertexContainer splitPts;
2261	Polygon3 frontPoly, backPoly;
2262
2263	const int cf = candidates[i]->
2264	ClassifyPlane(halfSpaces[j], mEpsilon);
2265
2266	switch (cf)
2267	{
2268	case Polygon3::SPLIT:
2269	frontPoly = new Polygon3();
2270	backPoly = new Polygon3();
2271
2272	candidates[i]->Split(halfSpaces[j],
2273	*frontPoly,
2274	*backPoly,
2275	mEpsilon);
2276
2277	DEL_PTR(candidates[i]);
2278
2279	if (frontPoly->Valid(mEpsilon))
2280	candidates[i] = frontPoly;
2281	else
2282	DEL_PTR(frontPoly);
2283
2284	DEL_PTR(backPoly);
2285	break;
2286	case Polygon3::BACK_SIDE:
2287	DEL_PTR(candidates[i]);
2288	break;
2289	// just take polygon as it is
2290	case Polygon3::FRONT_SIDE:
2291	case Polygon3::COINCIDENT:
2292	default:
2293	break;
2294	}
2295	}
2296
2297	if (candidates[i])
2298	geom.mPolys.push_back(candidates[i]);
2299	}
2300	}
2301
2302
2303	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2304	const bool onlyUnmailed) const
2305	{
2306	BspNodeGeometry geom;
2307	ConstructGeometry(n, geom);
2308
2309	stack<BspNode *> nodeStack;
2310	nodeStack.push(mRoot);
2311
2312	// planes needed to verify that we found neighbor leaf.
2313	vector<Plane3> halfSpaces;
2314	ExtractHalfSpaces(n, halfSpaces);
2315
2316	while (!nodeStack.empty())
2317	{
2318	BspNode *node = nodeStack.top();
2319	nodeStack.pop();
2320
2321	if (node->IsLeaf())
2322	{
2323	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2324	{
2325	// test all planes of current node if neighbour
2326	// candidate really is neighbour
2327	BspNodeGeometry candidateGeom;
2328	ConstructGeometry(node, candidateGeom);
2329
2330	bool isAdjacent = true;
2331	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2332	{
2333	const int cf =
2334	Polygon3::ClassifyPlane(candidateGeom.mPolys,
2335	halfSpaces[i],
2336	mEpsilon);
2337
2338	if (cf == Polygon3::BACK_SIDE)
2339	isAdjacent = false;
2340	}
2341
2342	if (isAdjacent)
2343	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2344	}
2345	}
2346	else
2347	{
2348	BspInterior interior = dynamic_cast<BspInterior >(node);
2349
2350	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2351	interior->mPlane,
2352	mEpsilon);
2353
2354	if (cf == Polygon3::FRONT_SIDE)
2355	nodeStack.push(interior->GetFront());
2356	else
2357	if (cf == Polygon3::BACK_SIDE)
2358	nodeStack.push(interior->GetBack());
2359	else
2360	{
2361	// random decision
2362	nodeStack.push(interior->GetBack());
2363	nodeStack.push(interior->GetFront());
2364	}
2365	}
2366	}
2367
2368	return (int)neighbors.size();
2369	}
2370
2371
2372	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2373	{
2374	stack<BspNode *> nodeStack;
2375	nodeStack.push(mRoot);
2376
2377	int mask = rand();
2378
2379	while (!nodeStack.empty())
2380	{
2381	BspNode *node = nodeStack.top();
2382	nodeStack.pop();
2383
2384	if (node->IsLeaf())
2385	{
2386	return dynamic_cast<BspLeaf *>(node);
2387	}
2388	else
2389	{
2390	BspInterior interior = dynamic_cast<BspInterior >(node);
2391	BspNode *next;
2392
2393	BspNodeGeometry geom;
2394	// todo: not very efficient: constructs full cell everytime
2395	ConstructGeometry(interior, geom);
2396
2397	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2398	halfspace,
2399	mEpsilon);
2400
2401	if (cf == Polygon3::BACK_SIDE)
2402	next = interior->GetFront();
2403	else
2404	if (cf == Polygon3::FRONT_SIDE)
2405	next = interior->GetFront();
2406	else
2407	{
2408	// random decision
2409	if (mask & 1)
2410	next = interior->GetBack();
2411	else
2412	next = interior->GetFront();
2413	mask = mask >> 1;
2414	}
2415
2416	nodeStack.push(next);
2417	}
2418	}
2419
2420	return NULL;
2421	}
2422
2423	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2424	{
2425	stack<BspNode *> nodeStack;
2426
2427	nodeStack.push(mRoot);
2428
2429	int mask = rand();
2430
2431	while (!nodeStack.empty())
2432	{
2433	BspNode *node = nodeStack.top();
2434	nodeStack.pop();
2435
2436	if (node->IsLeaf())
2437	{
2438	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2439	return dynamic_cast<BspLeaf *>(node);
2440	}
2441	else
2442	{
2443	BspInterior interior = dynamic_cast<BspInterior >(node);
2444
2445	// random decision
2446	if (mask & 1)
2447	nodeStack.push(interior->GetBack());
2448	else
2449	nodeStack.push(interior->GetFront());
2450
2451	mask = mask >> 1;
2452	}
2453	}
2454
2455	return NULL;
2456	}
2457
2458	void BspTree::AddToPvs(BspLeaf *leaf,
2459	const BoundedRayContainer &rays,
2460	int &sampleContributions,
2461	int &contributingSamples)
2462	{
2463	sampleContributions = 0;
2464	contributingSamples = 0;
2465
2466	BoundedRayContainer::const_iterator it, it_end = rays.end();
2467
2468	ViewCell *vc = leaf->GetViewCell();
2469
2470	// add contributions from samples to the PVS
2471	for (it = rays.begin(); it != it_end; ++ it)
2472	{
2473	int contribution = 0;
2474	Ray ray = (it)->mRay;
2475	float relContribution;
2476	if (!ray->intersections.empty())
2477	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2478	1.0f,
2479	relContribution);
2480
2481	if (ray->sourceObject.mObject)
2482	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2483	1.0f,
2484	relContribution);
2485
2486	if (contribution)
2487	{
2488	sampleContributions += contribution;
2489	++ contributingSamples;
2490	}
2491
2492	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2493	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2494	}
2495	}
2496
2497	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2498	{
2499	int pvsSize = 0;
2500
2501	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2502
2503	Intersectable::NewMail();
2504
2505	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2506	{
2507	Ray ray = (rit)->mRay;
2508
2509	if (!ray->intersections.empty())
2510	{
2511	if (!ray->intersections[0].mObject->Mailed())
2512	{
2513	ray->intersections[0].mObject->Mail();
2514	++ pvsSize;
2515	}
2516	}
2517	if (ray->sourceObject.mObject)
2518	{
2519	if (!ray->sourceObject.mObject->Mailed())
2520	{
2521	ray->sourceObject.mObject->Mail();
2522	++ pvsSize;
2523	}
2524	}
2525	}
2526
2527	return pvsSize;
2528	}
2529
2530	float BspTree::GetEpsilon() const
2531	{
2532	return mEpsilon;
2533	}
2534
2535
2536	/*************************************************************/
2537	/* BspNodeGeometry Implementation */
2538	/*************************************************************/
2539
2540
2541	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2542	{
2543	mPolys.reserve(rhs.mPolys.size());
2544
2545	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2546	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2547	{
2548	Polygon3 poly = it;
2549	mPolys.push_back(new Polygon3(*poly));
2550	}
2551	}
2552
2553
2554	BspNodeGeometry::~BspNodeGeometry()
2555	{
2556	CLEAR_CONTAINER(mPolys);
2557	}
2558
2559
2560	float BspNodeGeometry::GetArea() const
2561	{
2562	return Polygon3::GetArea(mPolys);
2563	}
2564
2565
2566	float BspNodeGeometry::GetVolume() const
2567	{
2568	//-- compute volume using tetrahedralization of the geometry
2569	// and adding the volume of the single tetrahedrons
2570	float volume = 0;
2571	const float f = 1.0f / 6.0f;
2572
2573	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2574
2575	// note: can take arbitrary point, e.g., the origin. However,
2576	// center of mass prevents precision errors
2577	const Vector3 center = CenterOfMass();
2578
2579	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2580	{
2581	Polygon3 poly = pit;
2582	const Vector3 v0 = poly->mVertices[0] - center;
2583
2584	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2585	{
2586	const Vector3 v1 = poly->mVertices[i] - center;
2587	const Vector3 v2 = poly->mVertices[i + 1] - center;
2588
2589	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2590	}
2591	}
2592
2593	return volume;
2594	}
2595
2596
2597	Vector3 BspNodeGeometry::CenterOfMass() const
2598	{
2599	int n = 0;
2600
2601	Vector3 center(0,0,0);
2602
2603	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2604
2605	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2606	{
2607	Polygon3 poly = pit;
2608
2609	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2610
2611	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2612	{
2613	center += *vit;
2614	++ n;
2615	}
2616	}
2617
2618	return center / (float)n;
2619	}
2620
2621
2622	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2623	{
2624	PolygonContainer::const_iterator it, it_end = mPolys.end();
2625
2626	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2627	{
2628	(*it)->AddToMesh(mesh);
2629	}
2630	}
2631
2632
2633	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2634	BspNodeGeometry &back,
2635	const Plane3 &splitPlane,
2636	const AxisAlignedBox3 &box,
2637	const float epsilon) const
2638	{
2639	// get cross section of new polygon
2640	Polygon3 *planePoly = box.CrossSection(splitPlane);
2641
2642	// split polygon with all other polygons
2643	planePoly = SplitPolygon(planePoly, epsilon);
2644
2645	//-- new polygon splits all other polygons
2646	for (int i = 0; i < (int)mPolys.size(); ++ i)
2647	{
2648	/// don't use epsilon here to get exact split planes
2649	const int cf =
2650	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2651
2652	switch (cf)
2653	{
2654	case Polygon3::SPLIT:
2655	{
2656	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2657
2658	Polygon3 *frontPoly = new Polygon3();
2659	Polygon3 *backPoly = new Polygon3();
2660
2661	poly->Split(splitPlane,
2662	*frontPoly,
2663	*backPoly,
2664	epsilon);
2665
2666	DEL_PTR(poly);
2667
2668	if (frontPoly->Valid(epsilon))
2669	front.mPolys.push_back(frontPoly);
2670	else
2671	DEL_PTR(frontPoly);
2672
2673	if (backPoly->Valid(epsilon))
2674	back.mPolys.push_back(backPoly);
2675	else
2676	DEL_PTR(backPoly);
2677	}
2678
2679	break;
2680	case Polygon3::BACK_SIDE:
2681	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2682	break;
2683	case Polygon3::FRONT_SIDE:
2684	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2685	break;
2686	case Polygon3::COINCIDENT:
2687	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2688	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2689	break;
2690	default:
2691	break;
2692	}
2693	}
2694
2695	//-- finally add the new polygon to the child node geometries
2696	if (planePoly)
2697	{
2698	// add polygon with normal pointing into positive half space to back cell
2699	back.mPolys.push_back(planePoly);
2700	// add polygon with reverse orientation to front cell
2701	front.mPolys.push_back(planePoly->CreateReversePolygon());
2702	}
2703
2704	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2705	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2706	}
2707
2708
2709	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2710	const float epsilon) const
2711	{
2712	if (!planePoly->Valid(epsilon))
2713	DEL_PTR(planePoly);
2714
2715	// polygon is split by all other planes
2716	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2717	{
2718	Plane3 plane = mPolys[i]->GetSupportingPlane();
2719
2720	/// don't use epsilon here to get exact split planes
2721	const int cf =
2722	planePoly->ClassifyPlane(plane, Limits::Small);
2723
2724	// split new polygon with all previous planes
2725	switch (cf)
2726	{
2727	case Polygon3::SPLIT:
2728	{
2729	Polygon3 *frontPoly = new Polygon3();
2730	Polygon3 *backPoly = new Polygon3();
2731
2732	planePoly->Split(plane,
2733	*frontPoly,
2734	*backPoly,
2735	epsilon);
2736
2737	// don't need anymore
2738	DEL_PTR(planePoly);
2739	DEL_PTR(frontPoly);
2740
2741	// back polygon is belonging to geometry
2742	if (backPoly->Valid(epsilon))
2743	planePoly = backPoly;
2744	else
2745	DEL_PTR(backPoly);
2746	}
2747	break;
2748	case Polygon3::FRONT_SIDE:
2749	DEL_PTR(planePoly);
2750	break;
2751	// polygon is taken as it is
2752	case Polygon3::BACK_SIDE:
2753	case Polygon3::COINCIDENT:
2754	default:
2755	break;
2756	}
2757	}
2758
2759	return planePoly;
2760	}
2761
2762
2763	ViewCell *
2764	BspTree::GetViewCell(const Vector3 &point)
2765	{
2766	if (mRoot == NULL)
2767	return NULL;
2768
2769
2770	stack<BspNode *> nodeStack;
2771	nodeStack.push(mRoot);
2772
2773	ViewCell *viewcell = NULL;
2774
2775	while (!nodeStack.empty()) {
2776	BspNode *node = nodeStack.top();
2777	nodeStack.pop();
2778
2779	if (node->IsLeaf()) {
2780	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
2781	break;
2782	} else {
2783
2784	BspInterior interior = dynamic_cast<BspInterior >(node);
2785
2786	// random decision
2787	if (interior->GetPlane().Side(point) < 0)
2788	nodeStack.push(interior->GetBack());
2789	else
2790	nodeStack.push(interior->GetFront());
2791	}
2792	}
2793
2794	return viewcell;
2795	}
2796
2797	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
2798	{
2799	Polygon3::IncludeInBox(mPolys, box);
2800	}

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