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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 472

Revision 472, 65.9 KB checked in by mattausch, 19 years ago (diff)
added priority queue to vspbsptree

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

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