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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 495

Revision 495, 67.1 KB checked in by mattausch, 19 years ago (diff)
fixed bug in tree collapse

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

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