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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 547

Revision 547, 68.9 KB checked in by mattausch, 18 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include "Triangle3.h"
11	#include "Tetrahedron3.h"
12
13	#include <stack>
14
15	#include "Exporter.h"
16	#include "Plane3.h"
17
18	//-- static members
19
20	int BspNode::sMailId = 1;
21
22	/** Evaluates split plane classification with respect to the plane's
23	contribution for a minimum number splits in the tree.
24	*/
25	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
26	/** Evaluates split plane classification with respect to the plane's
27	contribution for a balanced tree.
28	*/
29	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
30
31	/** Evaluates split plane classification with respect to the plane's
32	contribution for a minimum number of ray splits.
33	*/
34	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
35	/** Evaluates split plane classification with respect to the plane's
36	contribution for balanced rays.
37	*/
38	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
39
40	int BspTree::sFrontId = 0;
41	int BspTree::sBackId = 0;
42	int BspTree::sFrontAndBackId = 0;
43
44
45	/****************************************************************/
46	/* class BspNode implementation */
47	/****************************************************************/
48
49
50	BspNode::BspNode():
51	mParent(NULL), mTreeValid(true)
52	{}
53
54	BspNode::BspNode(BspInterior *parent):
55	mParent(parent), mTreeValid(true)
56	{}
57
58
59	bool BspNode::IsRoot() const
60	{
61	return mParent == NULL;
62	}
63
64
65	BspInterior *BspNode::GetParent()
66	{
67	return mParent;
68	}
69
70
71	void BspNode::SetParent(BspInterior *parent)
72	{
73	mParent = parent;
74	}
75
76
77	bool BspNode::IsSibling(BspNode *n) const
78	{
79	return ((this != n) && mParent &&
80	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
81	}
82
83
84	int BspNode::GetDepth() const
85	{
86	int depth = 0;
87	BspNode *p = mParent;
88
89	while (p)
90	{
91	p = p->mParent;
92	++ depth;
93	}
94
95	return depth;
96	}
97
98
99	bool BspNode::TreeValid() const
100	{
101	return mTreeValid;
102	}
103
104
105	void BspNode::SetTreeValid(const bool v)
106	{
107	mTreeValid = v;
108	}
109
110
111	/****************************************************************/
112	/* class BspInterior implementation */
113	/****************************************************************/
114
115
116	BspInterior::BspInterior(const Plane3 &plane):
117	mPlane(plane), mFront(NULL), mBack(NULL)
118	{}
119
120	BspInterior::~BspInterior()
121	{
122	DEL_PTR(mFront);
123	DEL_PTR(mBack);
124	}
125
126	bool BspInterior::IsLeaf() const
127	{
128	return false;
129	}
130
131	BspNode *BspInterior::GetBack()
132	{
133	return mBack;
134	}
135
136	BspNode *BspInterior::GetFront()
137	{
138	return mFront;
139	}
140
141	Plane3 BspInterior::GetPlane() const
142	{
143	return mPlane;
144	}
145
146	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
147	{
148	if (mBack == oldChild)
149	mBack = newChild;
150	else
151	mFront = newChild;
152	}
153
154	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
155	{
156	mBack = b;
157	mFront = f;
158	}
159
160	/****************************************************************/
161	/* class BspLeaf implementation */
162	/****************************************************************/
163
164
165	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
166	{
167	}
168
169
170	BspLeaf::~BspLeaf()
171	{
172	DEL_PTR(mPvs);
173	}
174
175
176	BspLeaf::BspLeaf(BspViewCell *viewCell):
177	mViewCell(viewCell)
178	{
179	}
180
181
182	BspLeaf::BspLeaf(BspInterior *parent):
183	BspNode(parent), mViewCell(NULL), mPvs(NULL)
184	{}
185
186
187
188	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
189	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
190	{
191	}
192
193	BspViewCell *BspLeaf::GetViewCell() const
194	{
195	return mViewCell;
196	}
197
198	void BspLeaf::SetViewCell(BspViewCell *viewCell)
199	{
200	mViewCell = viewCell;
201	}
202
203	bool BspLeaf::IsLeaf() const
204	{
205	return true;
206	}
207
208	/****************************************************************/
209	/* class BspTree implementation */
210	/****************************************************************/
211
212	BspTree::BspTree():
213	mRoot(NULL),
214	mUseAreaForPvs(true),
215	mGenerateViewCells(true)
216	{
217	Randomize(); // initialise random generator for heuristics
218
219	// the view cell corresponding to unbounded space
220	mRootCell = new BspViewCell();
221
222	//-- termination criteria for autopartition
223	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
224	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
225	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
226	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
227	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
228	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
229	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
230
231	//-- factors for bsp tree split plane heuristics
232	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
233	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
234	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
235	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
236	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
237	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
238	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
239	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
240	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
241	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
242
243	//-- termination criteria for axis aligned split
244	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
245	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
246	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
247	mTermMinPolysForAxisAligned);
248	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
249	mTermMinRaysForAxisAligned);
250	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
251	mTermMinObjectsForAxisAligned);
252	//-- partition criteria
253	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
254	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
255	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
256	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
257	environment->GetIntValue("BspTree.maxTests", mMaxTests);
258
259	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
260
261	Debug << "BSP max depth: " << mTermMaxDepth << endl;
262	Debug << "BSP min PVS: " << mTermMinPvs << endl;
263	Debug << "BSP min area: " << mTermMinArea << endl;
264	Debug << "BSP max polys: " << mTermMinPolys << endl;
265	Debug << "BSP max rays: " << mTermMinRays << endl;
266	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
267	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
268
269	Debug << "Split plane strategy: ";
270	if (mSplitPlaneStrategy & RANDOM_POLYGON)
271	Debug << "random polygon ";
272	if (mSplitPlaneStrategy & AXIS_ALIGNED)
273	Debug << "axis aligned ";
274	if (mSplitPlaneStrategy & LEAST_SPLITS)
275	Debug << "least splits ";
276	if (mSplitPlaneStrategy & BALANCED_POLYS)
277	Debug << "balanced polygons ";
278	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
279	Debug << "balanced view cells ";
280	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
281	Debug << "largest polygon area ";
282	if (mSplitPlaneStrategy & VERTICAL_AXIS)
283	Debug << "vertical axis ";
284	if (mSplitPlaneStrategy & BLOCKED_RAYS)
285	Debug << "blocked rays ";
286	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
287	Debug << "least ray splits ";
288	if (mSplitPlaneStrategy & BALANCED_RAYS)
289	Debug << "balanced rays ";
290	if (mSplitPlaneStrategy & PVS)
291	Debug << "pvs";
292
293	Debug << endl;
294	}
295
296
297	const BspTreeStatistics &BspTree::GetStatistics() const
298	{
299	return mStat;
300	}
301
302
303	int BspTree::SplitPolygons(const Plane3 &plane,
304	PolygonContainer &polys,
305	PolygonContainer &frontPolys,
306	PolygonContainer &backPolys,
307	PolygonContainer &coincident) const
308	{
309	int splits = 0;
310
311	#ifdef _Debug
312	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
313	#endif
314	while (!polys.empty())
315	{
316	Polygon3 *poly = polys.back();
317	polys.pop_back();
318
319	//-- classify polygon
320	const int cf = poly->ClassifyPlane(plane, mEpsilon);
321
322	switch (cf)
323	{
324	case Polygon3::COINCIDENT:
325	coincident.push_back(poly);
326	break;
327	case Polygon3::FRONT_SIDE:
328	frontPolys.push_back(poly);
329	break;
330	case Polygon3::BACK_SIDE:
331	backPolys.push_back(poly);
332	break;
333	case Polygon3::SPLIT:
334	{
335	Polygon3 *front_piece = new Polygon3(poly->mParent);
336	Polygon3 *back_piece = new Polygon3(poly->mParent);
337
338	//-- split polygon into front and back part
339	poly->Split(plane,
340	*front_piece,
341	*back_piece,
342	mEpsilon);
343
344	++ splits; // increase number of splits
345
346	//-- inherit rays from parent polygon for blocked ray criterium
347	poly->InheritRays(front_piece, back_piece);
348
349	// check if polygons still valid
350	if (front_piece->Valid(mEpsilon))
351	frontPolys.push_back(front_piece);
352	else
353	DEL_PTR(front_piece);
354
355	if (back_piece->Valid(mEpsilon))
356	backPolys.push_back(back_piece);
357	else
358	DEL_PTR(back_piece);
359
360	#ifdef _DEBUG
361	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
362	#endif
363	DEL_PTR(poly);
364	}
365	break;
366	default:
367	Debug << "SHOULD NEVER COME HERE\n";
368	break;
369	}
370	}
371
372	return splits;
373	}
374
375
376	void BspTreeStatistics::Print(ostream &app) const
377	{
378	app << "===== BspTree statistics ===============\n";
379
380	app << setprecision(4);
381
382	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
383
384	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
385
386	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
387
388	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
389
390	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
391
392	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
393
394	app << "#N_SPLITS ( Number of splits in axes x y z\n";
395
396	for (int i = 0; i < 3; ++ i)
397	app << splits[i] << " ";
398	app << endl;
399
400	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
401	<< maxDepthNodes * 100 / (double)Leaves() << endl;
402
403	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
404	<< minPvsNodes * 100 / (double)Leaves() << endl;
405
406	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
407	<< minRaysNodes * 100 / (double)Leaves() << endl;
408
409	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
410	<< maxCostNodes * 100 / (double)Leaves() << endl;
411
412	app << "#N_PMINAREALEAVES ( Percentage of leaves with mininum probability )\n"
413	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
414
415	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
416	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
417
418	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
419
420	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
421
422	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
423
424	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
425
426	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
427
428	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
429	//app << "#N_PVS: " << pvs << endl;
430
431	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
432	(polys + polySplits) / (double)polys << endl;
433
434	app << "===== END OF BspTree statistics ==========\n";
435	}
436
437
438	BspTree::~BspTree()
439	{
440	DEL_PTR(mRoot);
441
442	// HACK: view cells not generated => root cell not used
443	if (mGenerateViewCells)
444	DEL_PTR(mRootCell);
445	}
446
447	BspViewCell *BspTree::GetRootCell() const
448	{
449	return mRootCell;
450	}
451
452	void BspTree::InsertViewCell(ViewCell *viewCell)
453	{
454	PolygonContainer *polys = new PolygonContainer();
455
456	// don't generate new view cell, insert this one
457	mGenerateViewCells = false;
458	// extract polygons that guide the split process
459	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
460	mBox.Include(viewCell->GetBox()); // add to BSP aabb
461
462	InsertPolygons(polys);
463	}
464
465	void BspTree::InsertPolygons(PolygonContainer *polys)
466	{
467	BspTraversalStack tStack;
468
469	// traverse existing tree or create new tree
470	if (!mRoot)
471	mRoot = new BspLeaf();
472
473	tStack.push(BspTraversalData(mRoot,
474	polys,
475	0,
476	mRootCell,
477	new BoundedRayContainer(),
478	0,
479	mBox.SurfaceArea(),
480	new BspNodeGeometry()));
481
482	while (!tStack.empty())
483	{
484	// filter polygons donw the tree
485	BspTraversalData tData = tStack.top();
486	tStack.pop();
487
488	if (!tData.mNode->IsLeaf())
489	{
490	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
491
492	//-- filter view cell polygons down the tree until a leaf is reached
493	if (!tData.mPolygons->empty())
494	{
495	PolygonContainer *frontPolys = new PolygonContainer();
496	PolygonContainer *backPolys = new PolygonContainer();
497	PolygonContainer coincident;
498
499	int splits = 0;
500
501	// split viewcell polygons with respect to split plane
502	splits += SplitPolygons(interior->GetPlane(),
503	*tData.mPolygons,
504	*frontPolys,
505	*backPolys,
506	coincident);
507
508	// extract view cells associated with the split polygons
509	ViewCell *frontViewCell = mRootCell;
510	ViewCell *backViewCell = mRootCell;
511
512	BspTraversalData frontData(interior->GetFront(),
513	frontPolys,
514	tData.mDepth + 1,
515	mRootCell,
516	tData.mRays,
517	tData.mPvs,
518	mBox.SurfaceArea(),
519	new BspNodeGeometry());
520
521	BspTraversalData backData(interior->GetBack(),
522	backPolys,
523	tData.mDepth + 1,
524	mRootCell,
525	tData.mRays,
526	tData.mPvs,
527	mBox.SurfaceArea(),
528	new BspNodeGeometry());
529
530	if (!mGenerateViewCells)
531	{
532	ExtractViewCells(frontData,
533	backData,
534	coincident,
535	interior->mPlane);
536	}
537
538	// don't need coincident polygons anymore
539	CLEAR_CONTAINER(coincident);
540
541	mStat.polySplits += splits;
542
543	// push the children on the stack
544	tStack.push(frontData);
545	tStack.push(backData);
546	}
547
548	// cleanup
549	DEL_PTR(tData.mPolygons);
550	DEL_PTR(tData.mRays);
551	}
552	else
553	{
554	// reached leaf => subdivide current viewcell
555	BspNode *subRoot = Subdivide(tStack, tData);
556	}
557	}
558	}
559
560	int BspTree::AddMeshToPolygons(Mesh *mesh,
561	PolygonContainer &polys,
562	MeshInstance *parent)
563	{
564	FaceContainer::const_iterator fi;
565
566	// copy the face data to polygons
567	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
568	{
569	Polygon3 poly = new Polygon3((fi), mesh);
570
571	if (poly->Valid(mEpsilon))
572	{
573	poly->mParent = parent; // set parent intersectable
574	polys.push_back(poly);
575	}
576	else
577	DEL_PTR(poly);
578	}
579	return (int)mesh->mFaces.size();
580	}
581
582	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
583	PolygonContainer &polys,
584	int maxObjects)
585	{
586	int limit = (maxObjects > 0) ?
587	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
588
589	int polysSize = 0;
590
591	for (int i = 0; i < limit; ++ i)
592	{
593	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
594	{
595	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
596	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
597	}
598	}
599
600	return polysSize;
601	}
602
603	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
604	{
605	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
606
607	for (int i = 0; i < limit; ++i)
608	{
609	Intersectable object = objects[i];//it;
610	Mesh *mesh = NULL;
611
612	switch (object->Type()) // extract the meshes
613	{
614	case Intersectable::MESH_INSTANCE:
615	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
616	break;
617	case Intersectable::VIEW_CELL:
618	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
619	break;
620	// TODO: handle transformed mesh instances
621	default:
622	Debug << "intersectable type not supported" << endl;
623	break;
624	}
625
626	if (mesh) // copy the mesh data to polygons
627	{
628	mBox.Include(object->GetBox()); // add to BSP tree aabb
629	AddMeshToPolygons(mesh, polys, mRootCell);
630	}
631	}
632
633	return (int)polys.size();
634	}
635
636	void BspTree::Construct(const ViewCellContainer &viewCells)
637	{
638	mStat.nodes = 1;
639	mBox.Initialize(); // initialise bsp tree bounding box
640
641	// copy view cell meshes into one big polygon soup
642	PolygonContainer *polys = new PolygonContainer();
643	mStat.polys = AddToPolygonSoup(viewCells, *polys);
644
645	// view cells are given
646	mGenerateViewCells = false;
647	// construct tree from the view cell polygons
648	Construct(polys, new BoundedRayContainer());
649	}
650
651
652	void BspTree::Construct(const ObjectContainer &objects)
653	{
654	mStat.nodes = 1;
655	mBox.Initialize(); // initialise bsp tree bounding box
656
657	PolygonContainer *polys = new PolygonContainer();
658
659	mGenerateViewCells = true;
660	// copy mesh instance polygons into one big polygon soup
661	mStat.polys = AddToPolygonSoup(objects, *polys);
662
663	// construct tree from polygon soup
664	Construct(polys, new BoundedRayContainer());
665	}
666
667	void BspTree::Construct(const RayContainer &sampleRays)
668	{
669	mStat.nodes = 1;
670	mBox.Initialize(); // initialise BSP tree bounding box
671
672	PolygonContainer *polys = new PolygonContainer();
673	BoundedRayContainer *rays = new BoundedRayContainer();
674
675	RayContainer::const_iterator rit, rit_end = sampleRays.end();
676
677	// generate view cells
678	mGenerateViewCells = true;
679
680	long startTime = GetTime();
681
682	Debug << "** Extracting polygons from rays **\n";
683
684	std::map<Face , Polygon3 > facePolyMap;
685
686	//-- extract polygons intersected by the rays
687	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
688	{
689	Ray ray = rit;
690
691	// get ray-face intersection. Store polygon representing the rays together
692	// with rays intersecting the face.
693	if (!ray->intersections.empty())
694	{
695	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
696	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
697
698	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
699
700	if (it != facePolyMap.end())
701	{
702	//store rays if needed for heuristics
703	if (mSplitPlaneStrategy & BLOCKED_RAYS)
704	(*it).second->mPiercingRays.push_back(ray);
705	}
706	else
707	{ //store rays if needed for heuristics
708	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
709	poly->mParent = obj;
710	polys->push_back(poly);
711
712	if (mSplitPlaneStrategy & BLOCKED_RAYS)
713	poly->mPiercingRays.push_back(ray);
714
715	facePolyMap[face] = poly;
716	}
717	}
718	}
719
720	facePolyMap.clear();
721
722	// compute bounding box
723	Polygon3::IncludeInBox(*polys, mBox);
724
725	//-- store rays
726	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
727	{
728	Ray ray = rit;
729	ray->SetId(-1); // reset id
730
731	float minT, maxT;
732	if (mBox.GetRaySegment(*ray, minT, maxT))
733	rays->push_back(new BoundedRay(ray, minT, maxT));
734	}
735
736	mStat.polys = (int)polys->size();
737
738	Debug << "** Finished polygon extraction **" << endl;
739	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
740	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
741
742	Construct(polys, rays);
743	}
744
745	void BspTree::Construct(const ObjectContainer &objects, const RayContainer &sampleRays)
746	{
747	mStat.nodes = 1;
748	mBox.Initialize(); // initialise BSP tree bounding box
749
750	BoundedRayContainer *rays = new BoundedRayContainer();
751	PolygonContainer *polys = new PolygonContainer();
752
753	mGenerateViewCells = true;
754
755	// copy mesh instance polygons into one big polygon soup
756	mStat.polys = AddToPolygonSoup(objects, *polys);
757
758	RayContainer::const_iterator rit, rit_end = sampleRays.end();
759
760	//-- store rays
761	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
762	{
763	Ray ray = rit;
764	ray->SetId(-1); // reset id
765
766	float minT, maxT;
767	if (mBox.GetRaySegment(*ray, minT, maxT))
768	rays->push_back(new BoundedRay(ray, minT, maxT));
769	}
770
771	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
772	Construct(polys, rays);
773	}
774
775	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
776	{
777	BspTraversalStack tStack;
778
779	mRoot = new BspLeaf();
780
781	// constrruct root node geometry
782	BspNodeGeometry *geom = new BspNodeGeometry();
783	ConstructGeometry(mRoot, *geom);
784
785	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
786	ComputePvsSize(*rays), geom->GetArea(), geom);
787
788	tStack.push(tData);
789
790	mStat.Start();
791	cout << "Contructing bsp tree ... ";
792	long startTime = GetTime();
793	while (!tStack.empty())
794	{
795	tData = tStack.top();
796
797	tStack.pop();
798
799	// subdivide leaf node
800	BspNode *r = Subdivide(tStack, tData);
801
802	if (r == mRoot)
803	Debug << "BSP tree construction time spent at root: " << TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
804	}
805
806	cout << "finished\n";
807
808	mStat.Stop();
809	}
810
811	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
812	{
813	return
814	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
815	((int)data.mRays->size() <= mTermMinRays) \|\|
816	(data.mPvs <= mTermMinPvs) \|\|
817	(data.mArea <= mTermMinArea) \|\|
818	(data.mDepth >= mTermMaxDepth) \|\|
819	(data.GetAvgRayContribution() < mTermMaxRayContribution));
820	}
821
822	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
823	{
824	//-- terminate traversal
825	if (TerminationCriteriaMet(tData))
826	{
827	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
828
829	BspViewCell *viewCell;
830
831	// generate new view cell for each leaf
832	if (mGenerateViewCells)
833	viewCell = new BspViewCell();
834	else
835	// add view cell to leaf
836	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
837
838	leaf->SetViewCell(viewCell);
839	viewCell->mLeaves.push_back(leaf);
840
841	//-- add pvs
842	if (viewCell != mRootCell)
843	{
844	int conSamp = 0, sampCon = 0;
845	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
846
847	mStat.contributingSamples += conSamp;
848	mStat.sampleContributions += sampCon;
849	}
850
851	EvaluateLeafStats(tData);
852
853	//-- clean up
854
855	// discard polygons
856	CLEAR_CONTAINER(*tData.mPolygons);
857	// discard rays
858	CLEAR_CONTAINER(*tData.mRays);
859
860	DEL_PTR(tData.mPolygons);
861	DEL_PTR(tData.mRays);
862	DEL_PTR(tData.mGeometry);
863
864	return leaf;
865	}
866
867	//-- continue subdivision
868	PolygonContainer coincident;
869
870	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
871	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
872	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
873	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
874
875	// create new interior node and two leaf nodes
876	BspInterior *interior =
877	SubdivideNode(tData, tFrontData, tBackData, coincident);
878
879	#ifdef _DEBUG
880	// if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
881	// { for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
882	// Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
883	// Debug << endl;}
884	#endif
885
886	// extract view cells from coincident polygons according to plane normal
887	// only if front or back polygons are empty
888	if (!mGenerateViewCells)
889	{
890	ExtractViewCells(tFrontData,
891	tBackData,
892	coincident,
893	interior->mPlane);
894	}
895
896	// don't need coincident polygons anymory
897	CLEAR_CONTAINER(coincident);
898
899	// push the children on the stack
900	tStack.push(tFrontData);
901	tStack.push(tBackData);
902
903	// cleanup
904	DEL_PTR(tData.mNode);
905
906	DEL_PTR(tData.mPolygons);
907	DEL_PTR(tData.mRays);
908	DEL_PTR(tData.mGeometry);
909
910	return interior;
911	}
912
913	void BspTree::ExtractViewCells(BspTraversalData &frontData,
914	BspTraversalData &backData,
915	const PolygonContainer &coincident,
916	const Plane3 &splitPlane) const
917	{
918	// if not empty, tree is further subdivided => don't have to find view cell
919	bool foundFront = !frontData.mPolygons->empty();
920	bool foundBack = !frontData.mPolygons->empty();
921
922	PolygonContainer::const_iterator it =
923	coincident.begin(), it_end = coincident.end();
924
925	//-- find first view cells in front and back leafs
926	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
927	{
928	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
929	{
930	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
931	foundBack = true;
932	}
933	else
934	{
935	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
936	foundFront = true;
937	}
938	}
939	}
940
941	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
942	BspTraversalData &frontData,
943	BspTraversalData &backData,
944	PolygonContainer &coincident)
945	{
946	mStat.nodes += 2;
947
948	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
949
950	Debug << "*********************" << endl;
951	long startTime = GetTime();
952
953	// select subdivision plane
954	BspInterior *interior =
955	new BspInterior(SelectPlane(leaf, tData));
956	Debug << "time used for split plane selection: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
957	#ifdef _DEBUG
958	Debug << interior << endl;
959	#endif
960
961
962	Debug << "number of rays: " << (int)tData.mRays->size() << endl;
963	Debug << "number of polys: " << (int)tData.mPolygons->size() << endl;
964
965	startTime = GetTime();
966
967	// subdivide rays into front and back rays
968	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
969
970	Debug << "time used for rays splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
971
972	startTime = GetTime();
973	// subdivide polygons with plane
974	mStat.polySplits += SplitPolygons(interior->GetPlane(),
975	*tData.mPolygons,
976	*frontData.mPolygons,
977	*backData.mPolygons,
978	coincident);
979
980	Debug << "time used for polygon splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
981
982	// compute pvs
983	frontData.mPvs = ComputePvsSize(*frontData.mRays);
984	backData.mPvs = ComputePvsSize(*backData.mRays);
985
986	// split geometry and compute area
987	if (1)
988	{
989	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
990	*backData.mGeometry,
991	interior->mPlane,
992	mBox,
993	mEpsilon);
994
995
996	frontData.mArea = frontData.mGeometry->GetArea();
997	backData.mArea = backData.mGeometry->GetArea();
998	}
999
1000	// compute accumulated ray length
1001	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
1002	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
1003
1004	//-- create front and back leaf
1005
1006	BspInterior *parent = leaf->GetParent();
1007
1008	// replace a link from node's parent
1009	if (!leaf->IsRoot())
1010	{
1011	parent->ReplaceChildLink(leaf, interior);
1012	interior->SetParent(parent);
1013	}
1014	else // new root
1015	{
1016	mRoot = interior;
1017	}
1018
1019	// and setup child links
1020	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1021
1022	frontData.mNode = interior->GetFront();
1023	backData.mNode = interior->GetBack();
1024
1025	//DEL_PTR(leaf);
1026	return interior;
1027	}
1028
1029	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1030	const int axis,
1031	vector<SortableEntry> &splitCandidates) const
1032	{
1033	splitCandidates.clear();
1034
1035	int requestedSize = 2 * (int)polys.size();
1036	// creates a sorted split candidates array
1037	splitCandidates.reserve(requestedSize);
1038
1039	PolygonContainer::const_iterator it, it_end = polys.end();
1040
1041	AxisAlignedBox3 box;
1042
1043	// insert all queries
1044	for(it = polys.begin(); it != it_end; ++ it)
1045	{
1046	box.Initialize();
1047	box.Include((it));
1048
1049	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1050	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1051	}
1052
1053	stable_sort(splitCandidates.begin(), splitCandidates.end());
1054	}
1055
1056
1057	float BspTree::BestCostRatio(const PolygonContainer &polys,
1058	const AxisAlignedBox3 &box,
1059	const int axis,
1060	float &position,
1061	int &objectsBack,
1062	int &objectsFront) const
1063	{
1064	vector<SortableEntry> splitCandidates;
1065
1066	SortSplitCandidates(polys, axis, splitCandidates);
1067
1068	// go through the lists, count the number of objects left and right
1069	// and evaluate the following cost funcion:
1070	// C = ct_div_ci + (ol + or)/queries
1071
1072	int objectsLeft = 0, objectsRight = (int)polys.size();
1073
1074	float minBox = box.Min(axis);
1075	float maxBox = box.Max(axis);
1076	float boxArea = box.SurfaceArea();
1077
1078	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1079	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1080
1081	float minSum = 1e20f;
1082	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1083
1084	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1085	{
1086	switch ((*ci).type)
1087	{
1088	case SortableEntry::POLY_MIN:
1089	++ objectsLeft;
1090	break;
1091	case SortableEntry::POLY_MAX:
1092	-- objectsRight;
1093	break;
1094	default:
1095	break;
1096	}
1097
1098	if ((ci).value > minBand && (ci).value < maxBand)
1099	{
1100	AxisAlignedBox3 lbox = box;
1101	AxisAlignedBox3 rbox = box;
1102	lbox.SetMax(axis, (*ci).value);
1103	rbox.SetMin(axis, (*ci).value);
1104
1105	const float sum = objectsLeft * lbox.SurfaceArea() +
1106	objectsRight * rbox.SurfaceArea();
1107
1108	if (sum < minSum)
1109	{
1110	minSum = sum;
1111	position = (*ci).value;
1112
1113	objectsBack = objectsLeft;
1114	objectsFront = objectsRight;
1115	}
1116	}
1117	}
1118
1119	const float oldCost = (float)polys.size();
1120	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1121	const float ratio = newCost / oldCost;
1122
1123
1124	#if 0
1125	Debug << "====================" << endl;
1126	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1127	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1128	#endif
1129	return ratio;
1130	}
1131
1132	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1133	const PolygonContainer &polys) const
1134	{
1135	AxisAlignedBox3 box;
1136	box.Initialize();
1137
1138	// create bounding box of region
1139	Polygon3::IncludeInBox(polys, box);
1140
1141	int objectsBack = 0, objectsFront = 0;
1142	int axis = 0;
1143	float costRatio = MAX_FLOAT;
1144	Vector3 position;
1145
1146	//-- area subdivision
1147	for (int i = 0; i < 3; ++ i)
1148	{
1149	float p = 0;
1150	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1151
1152	if (r < costRatio)
1153	{
1154	costRatio = r;
1155	axis = i;
1156	position = p;
1157	}
1158	}
1159
1160	if (costRatio >= mMaxCostRatio)
1161	return false;
1162
1163	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1164	plane = Plane3(norm, position);
1165
1166	return true;
1167	}
1168
1169
1170	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1171	{
1172	if (data.mPolygons->empty() && data.mRays->empty())
1173	{
1174	Debug << "Warning: No autopartition polygon candidate available\n";
1175
1176	// return axis aligned split
1177	AxisAlignedBox3 box;
1178	box.Initialize();
1179
1180	// create bounding box of region
1181	Polygon3::IncludeInBox(*data.mPolygons, box);
1182
1183	const int axis = box.Size().DrivingAxis();
1184	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1185
1186	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1187	return Plane3(norm, position);
1188	}
1189
1190	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1191	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1192	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1193	((mTermMinObjectsForAxisAligned < 0) \|\|
1194	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1195	{
1196	Plane3 plane;
1197	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1198	return plane;
1199	}
1200
1201	// simplest strategy: just take next polygon
1202	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1203	{
1204	if (!data.mPolygons->empty())
1205	{
1206	Polygon3 *nextPoly =
1207	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1208	return nextPoly->GetSupportingPlane();
1209	}
1210	else
1211	{
1212	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1213	BoundedRay bRay = (data.mRays)[candidateIdx];
1214
1215	Ray *ray = bRay->mRay;
1216
1217	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1218	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1219
1220	const Vector3 pt = (maxPt + minPt) * 0.5;
1221
1222	const Vector3 normal = ray->GetDir();
1223
1224	return Plane3(normal, pt);
1225	}
1226
1227	return Plane3();
1228	}
1229
1230	// use heuristics to find appropriate plane
1231	return SelectPlaneHeuristics(leaf, data);
1232	}
1233
1234
1235	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1236	{
1237	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1238	BoundedRay *bRay = rays[candidateIdx];
1239	Ray *ray = bRay->mRay;
1240
1241	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1242	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1243
1244	const Vector3 pt = (maxPt + minPt) * 0.5;
1245
1246	const Vector3 normal = ray->GetDir();
1247
1248	return Plane3(normal, pt);
1249	}
1250
1251	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1252	{
1253	Vector3 pt[3];
1254	int idx[3];
1255	int cmaxT = 0;
1256	int cminT = 0;
1257	bool chooseMin = false;
1258
1259	for (int j = 0; j < 3; j ++)
1260	{
1261	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1262
1263	if (idx[j] >= (int)rays.size())
1264	{
1265	idx[j] -= (int)rays.size();
1266	chooseMin = (cminT < 2);
1267	}
1268	else
1269	chooseMin = (cmaxT < 2);
1270
1271	BoundedRay *bRay = rays[idx[j]];
1272	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1273	bRay->mRay->Extrap(bRay->mMaxT);
1274	}
1275
1276	return Plane3(pt[0], pt[1], pt[2]);
1277	}
1278
1279	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1280	{
1281	Vector3 pt[3];
1282
1283	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1284	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1285
1286	// check if rays different
1287	if (idx1 == idx2)
1288	idx2 = (idx2 + 1) % (int)rays.size();
1289
1290	const BoundedRay *ray1 = rays[idx1];
1291	const BoundedRay *ray2 = rays[idx2];
1292
1293	// normal vector of the plane parallel to both lines
1294	const Vector3 norm =
1295	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1296
1297	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1298	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1299
1300	// vector from line 1 to line 2
1301	const Vector3 vd = orig1 - orig2;
1302
1303	// project vector on normal to get distance
1304	const float dist = DotProd(vd, norm);
1305
1306	// point on plane lies halfway between the two planes
1307	const Vector3 planePt = orig1 + norm * dist * 0.5;
1308
1309	return Plane3(norm, planePt);
1310	}
1311
1312
1313	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1314	{
1315	float lowestCost = MAX_FLOAT;
1316	Plane3 bestPlane;
1317	// intermediate plane
1318	Plane3 plane;
1319
1320	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1321	int maxIdx = (int)data.mPolygons->size();
1322
1323	for (int i = 0; i < limit; ++ i)
1324	{
1325	// assure that no index is taken twice
1326	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1327	//Debug << "current Idx: " << maxIdx << " cand idx " << candidateIdx << endl;
1328
1329	Polygon3 poly = (data.mPolygons)[candidateIdx];
1330
1331	// swap candidate to the end to avoid testing same plane
1332	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1333
1334	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1335
1336	// evaluate current candidate
1337	const float candidateCost =
1338	SplitPlaneCost(poly->GetSupportingPlane(), data);
1339
1340	if (candidateCost < lowestCost)
1341	{
1342	bestPlane = poly->GetSupportingPlane();
1343	lowestCost = candidateCost;
1344	}
1345	}
1346
1347	//-- choose candidate planes extracted from rays
1348	for (int i = 0; i < mMaxRayCandidates; ++ i)
1349	{
1350	plane = ChooseCandidatePlane3(*data.mRays);
1351	const float candidateCost = SplitPlaneCost(plane, data);
1352
1353	if (candidateCost < lowestCost)
1354	{
1355	bestPlane = plane;
1356	lowestCost = candidateCost;
1357	}
1358	}
1359
1360	#ifdef _DEBUG
1361	Debug << "plane lowest cost: " << lowestCost << endl;
1362	#endif
1363
1364	return bestPlane;
1365	}
1366
1367
1368	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1369	const PolygonContainer &polys) const
1370	{
1371	float val = 0;
1372
1373	float sumBalancedPolys = 0;
1374	float sumSplits = 0;
1375	float sumPolyArea = 0;
1376	float sumBalancedViewCells = 0;
1377	float sumBlockedRays = 0;
1378	float totalBlockedRays = 0;
1379	//float totalArea = 0;
1380	int totalViewCells = 0;
1381
1382	// need three unique ids for each type of view cell
1383	// for balanced view cells criterium
1384	ViewCell::NewMail();
1385	const int backId = ViewCell::sMailId;
1386	ViewCell::NewMail();
1387	const int frontId = ViewCell::sMailId;
1388	ViewCell::NewMail();
1389	const int frontAndBackId = ViewCell::sMailId;
1390
1391	bool useRand;;
1392	int limit;
1393
1394	// choose test polyongs randomly if over threshold
1395	if ((int)polys.size() > mMaxTests)
1396	{
1397	useRand = true;
1398	limit = mMaxTests;
1399	}
1400	else
1401	{
1402	useRand = false;
1403	limit = (int)polys.size();
1404	}
1405
1406	for (int i = 0; i < limit; ++ i)
1407	{
1408	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1409
1410	Polygon3 *poly = polys[testIdx];
1411
1412	const int classification =
1413	poly->ClassifyPlane(candidatePlane, mEpsilon);
1414
1415	if (mSplitPlaneStrategy & BALANCED_POLYS)
1416	sumBalancedPolys += sBalancedPolysTable[classification];
1417
1418	if (mSplitPlaneStrategy & LEAST_SPLITS)
1419	sumSplits += sLeastPolySplitsTable[classification];
1420
1421	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1422	{
1423	if (classification == Polygon3::COINCIDENT)
1424	sumPolyArea += poly->GetArea();
1425	//totalArea += area;
1426	}
1427
1428	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1429	{
1430	const float blockedRays = (float)poly->mPiercingRays.size();
1431
1432	if (classification == Polygon3::COINCIDENT)
1433	sumBlockedRays += blockedRays;
1434
1435	totalBlockedRays += blockedRays;
1436	}
1437
1438	// assign view cells to back or front according to classificaion
1439	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1440	{
1441	MeshInstance *viewCell = poly->mParent;
1442
1443	// assure that we only count a view cell
1444	// once for the front and once for the back side of the plane
1445	if (classification == Polygon3::FRONT_SIDE)
1446	{
1447	if ((viewCell->mMailbox != frontId) &&
1448	(viewCell->mMailbox != frontAndBackId))
1449	{
1450	sumBalancedViewCells += 1.0;
1451
1452	if (viewCell->mMailbox != backId)
1453	viewCell->mMailbox = frontId;
1454	else
1455	viewCell->mMailbox = frontAndBackId;
1456
1457	++ totalViewCells;
1458	}
1459	}
1460	else if (classification == Polygon3::BACK_SIDE)
1461	{
1462	if ((viewCell->mMailbox != backId) &&
1463	(viewCell->mMailbox != frontAndBackId))
1464	{
1465	sumBalancedViewCells -= 1.0;
1466
1467	if (viewCell->mMailbox != frontId)
1468	viewCell->mMailbox = backId;
1469	else
1470	viewCell->mMailbox = frontAndBackId;
1471
1472	++ totalViewCells;
1473	}
1474	}
1475	}
1476	}
1477
1478	const float polysSize = (float)polys.size() + Limits::Small;
1479
1480	// all values should be approx. between 0 and 1 so they can be combined
1481	// and scaled with the factors according to their importance
1482	if (mSplitPlaneStrategy & BALANCED_POLYS)
1483	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1484
1485	if (mSplitPlaneStrategy & LEAST_SPLITS)
1486	val += mLeastSplitsFactor * sumSplits / polysSize;
1487
1488	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1489	// HACK: polys.size should be total area so scaling is between 0 and 1
1490	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1491
1492	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1493	if (totalBlockedRays != 0)
1494	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1495
1496	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1497	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1498	((float)totalViewCells + Limits::Small);
1499
1500	return val;
1501	}
1502
1503
1504	inline void BspTree::GenerateUniqueIdsForPvs()
1505	{
1506	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1507	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1508	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1509	}
1510
1511	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1512	const BoundedRayContainer &rays,
1513	const int pvs,
1514	const float area,
1515	const BspNodeGeometry &cell) const
1516	{
1517	float val = 0;
1518
1519	float sumBalancedRays = 0;
1520	float sumRaySplits = 0;
1521
1522	int frontPvs = 0;
1523	int backPvs = 0;
1524
1525	// probability that view point lies in child
1526	float pOverall = 0;
1527	float pFront = 0;
1528	float pBack = 0;
1529
1530	const bool pvsUseLen = false;
1531
1532	if (mSplitPlaneStrategy & PVS)
1533	{
1534	// create unique ids for pvs heuristics
1535	GenerateUniqueIdsForPvs();
1536
1537	if (mUseAreaForPvs) // use front and back cell areas to approximate volume
1538	{
1539	// construct child geometry with regard to the candidate split plane
1540	BspNodeGeometry frontCell;
1541	BspNodeGeometry backCell;
1542
1543	cell.SplitGeometry(frontCell,
1544	backCell,
1545	candidatePlane,
1546	mBox,
1547	mEpsilon);
1548
1549	pFront = frontCell.GetArea();
1550	pBack = backCell.GetArea();
1551
1552	pOverall = area;
1553	}
1554	}
1555
1556	bool useRand;
1557	int limit;
1558
1559	// choose test polyongs randomly if over threshold
1560	if ((int)rays.size() > mMaxTests)
1561	{
1562	useRand = true;
1563	limit = mMaxTests;
1564	}
1565	else
1566	{
1567	useRand = false;
1568	limit = (int)rays.size();
1569	}
1570
1571	for (int i = 0; i < limit; ++ i)
1572	{
1573	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1574
1575	BoundedRay *bRay = rays[testIdx];
1576
1577	Ray *ray = bRay->mRay;
1578	const float minT = bRay->mMinT;
1579	const float maxT = bRay->mMaxT;
1580
1581	Vector3 entP, extP;
1582
1583	const int cf =
1584	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1585
1586	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1587	{
1588	sumBalancedRays += sBalancedRaysTable[cf];
1589	}
1590
1591	if (mSplitPlaneStrategy & BALANCED_RAYS)
1592	{
1593	sumRaySplits += sLeastRaySplitsTable[cf];
1594	}
1595
1596	if (mSplitPlaneStrategy & PVS)
1597	{
1598	// in case the ray intersects an object
1599	// assure that we only count the object
1600	// once for the front and once for the back side of the plane
1601
1602	// add the termination object
1603	if (!ray->intersections.empty())
1604	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1605
1606	// add the source object
1607	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1608
1609	if (mUseAreaForPvs)
1610	{
1611	float len = 1;
1612
1613	if (pvsUseLen)
1614	len = SqrDistance(entP, extP);
1615
1616	// use length of rays to approximate volume
1617	if (Ray::BACK && Ray::COINCIDENT)
1618	pBack += len;
1619	if (Ray::FRONT && Ray::COINCIDENT)
1620	pFront += len;
1621	if (Ray::FRONT_BACK \|\| Ray::BACK_FRONT)
1622	{
1623	if (pvsUseLen)
1624	{
1625	const Vector3 extp = ray->Extrap(maxT);
1626	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1627
1628	const float newT = t * maxT;
1629	const float newLen = SqrDistance(ray->Extrap(newT), extp);
1630
1631	if (Ray::FRONT_BACK)
1632	{
1633	pFront += len - newLen;
1634	pBack += newLen;
1635	}
1636	else
1637	{
1638	pBack += len - newLen;
1639	pFront += newLen;
1640	}
1641	}
1642	else
1643	{
1644	++ pFront;
1645	++ pBack;
1646	}
1647	}
1648	}
1649	}
1650	}
1651
1652	const float raysSize = (float)rays.size() + Limits::Small;
1653
1654	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1655	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1656
1657	if (mSplitPlaneStrategy & BALANCED_RAYS)
1658	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1659
1660	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1661
1662	if (mSplitPlaneStrategy & PVS)
1663	{
1664	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1665
1666	// give penalty to unbalanced split
1667	if (0)
1668	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1669	(pFront < (pBack * 0.2 + Limits::Small)))
1670	val += 0.5;
1671	}
1672
1673
1674	#ifdef _DEBUG
1675	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1676	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1677	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1678	#endif
1679
1680	return val;
1681	}
1682
1683	void BspTree::AddObjToPvs(Intersectable *obj,
1684	const int cf,
1685	int &frontPvs,
1686	int &backPvs) const
1687	{
1688	if (!obj)
1689	return;
1690	// TODO: does this really belong to no pvs?
1691	//if (cf == Ray::COINCIDENT) return;
1692
1693	// object belongs to both PVS
1694	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1695	(cf == Ray::BACK_FRONT) \|\|
1696	(cf == Ray::COINCIDENT);
1697
1698	if ((cf == Ray::FRONT) \|\| bothSides)
1699	{
1700	if ((obj->mMailbox != sFrontId) &&
1701	(obj->mMailbox != sFrontAndBackId))
1702	{
1703	++ frontPvs;
1704
1705	if (obj->mMailbox == sBackId)
1706	obj->mMailbox = sFrontAndBackId;
1707	else
1708	obj->mMailbox = sFrontId;
1709	}
1710	}
1711
1712	if ((cf == Ray::BACK) \|\| bothSides)
1713	{
1714	if ((obj->mMailbox != sBackId) &&
1715	(obj->mMailbox != sFrontAndBackId))
1716	{
1717	++ backPvs;
1718
1719	if (obj->mMailbox == sFrontId)
1720	obj->mMailbox = sFrontAndBackId;
1721	else
1722	obj->mMailbox = sBackId;
1723	}
1724	}
1725	}
1726
1727	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1728	BspTraversalData &data) const
1729	{
1730	float val = 0;
1731
1732	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1733	{
1734	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1735	// we put a penalty on the dot product between the "tiny" vertical axis
1736	// and the split plane axis
1737	val += mVerticalSplitsFactor *
1738	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1739	}
1740
1741	// the following criteria loop over all polygons to find the cost value
1742	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1743	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1744	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1745	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1746	(mSplitPlaneStrategy & BLOCKED_RAYS))
1747	{
1748	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1749	}
1750
1751	// the following criteria loop over all rays to find the cost value
1752	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1753	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1754	(mSplitPlaneStrategy & PVS))
1755	{
1756	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1757	data.mArea, *data.mGeometry);
1758	}
1759
1760	// return linear combination of the sums
1761	return val;
1762	}
1763
1764	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1765	{
1766	stack<BspNode *> nodeStack;
1767	nodeStack.push(mRoot);
1768
1769	while (!nodeStack.empty())
1770	{
1771	BspNode *node = nodeStack.top();
1772
1773	nodeStack.pop();
1774
1775	if (node->IsLeaf())
1776	{
1777	BspLeaf leaf = (BspLeaf )node;
1778	leaves.push_back(leaf);
1779	}
1780	else
1781	{
1782	BspInterior interior = dynamic_cast<BspInterior >(node);
1783
1784	nodeStack.push(interior->GetBack());
1785	nodeStack.push(interior->GetFront());
1786	}
1787	}
1788	}
1789
1790
1791	AxisAlignedBox3 BspTree::GetBoundingBox() const
1792	{
1793	return mBox;
1794	}
1795
1796
1797	BspNode *BspTree::GetRoot() const
1798	{
1799	return mRoot;
1800	}
1801
1802	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1803	{
1804	// the node became a leaf -> evaluate stats for leafs
1805	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1806
1807	// store maximal and minimal depth
1808	if (data.mDepth > mStat.maxDepth)
1809	mStat.maxDepth = data.mDepth;
1810
1811	if (data.mDepth < mStat.minDepth)
1812	mStat.minDepth = data.mDepth;
1813
1814	// accumulate depth to compute average depth
1815	mStat.accumDepth += data.mDepth;
1816	// accumulate rays to compute rays / leaf
1817	mStat.accumRays += (int)data.mRays->size();
1818
1819	if (data.mDepth >= mTermMaxDepth)
1820	++ mStat.maxDepthNodes;
1821
1822	if (data.mPvs < mTermMinPvs)
1823	++ mStat.minPvsNodes;
1824
1825	if ((int)data.mRays->size() < mTermMinRays)
1826	++ mStat.minRaysNodes;
1827
1828	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1829	++ mStat.maxRayContribNodes;
1830
1831	if (data.mGeometry->GetArea() <= mTermMinArea)
1832	++ mStat.minProbabilityNodes;
1833
1834	#ifdef _DEBUG
1835	Debug << "BSP stats: "
1836	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1837	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1838	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1839	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1840	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1841	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1842	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1843	#endif
1844	}
1845
1846	int
1847	BspTree::_CastRay(Ray &ray)
1848	{
1849	int hits = 0;
1850
1851	stack<BspRayTraversalData> tStack;
1852
1853	float maxt, mint;
1854
1855	if (!mBox.GetRaySegment(ray, mint, maxt))
1856	return 0;
1857
1858	Intersectable::NewMail();
1859
1860	Vector3 entp = ray.Extrap(mint);
1861	Vector3 extp = ray.Extrap(maxt);
1862
1863	BspNode *node = mRoot;
1864	BspNode *farChild = NULL;
1865
1866	while (1)
1867	{
1868	if (!node->IsLeaf())
1869	{
1870	BspInterior in = dynamic_cast<BspInterior >(node);
1871
1872	Plane3 splitPlane = in->GetPlane();
1873	const int entSide = splitPlane.Side(entp);
1874	const int extSide = splitPlane.Side(extp);
1875
1876	if (entSide < 0)
1877	{
1878	node = in->GetBack();
1879
1880	if(extSide <= 0) // plane does not split ray => no far child
1881	continue;
1882
1883	farChild = in->GetFront(); // plane splits ray
1884
1885	} else if (entSide > 0)
1886	{
1887	node = in->GetFront();
1888
1889	if (extSide >= 0) // plane does not split ray => no far child
1890	continue;
1891
1892	farChild = in->GetBack(); // plane splits ray
1893	}
1894	else // ray and plane are coincident
1895	{
1896	// WHAT TO DO IN THIS CASE ?
1897	//break;
1898	node = in->GetFront();
1899	continue;
1900	}
1901
1902	// push data for far child
1903	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1904
1905	// find intersection of ray segment with plane
1906	float t;
1907	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
1908	maxt *= t;
1909
1910	} else // reached leaf => intersection with view cell
1911	{
1912	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1913
1914	if (!leaf->mViewCell->Mailed())
1915	{
1916	// ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1917	leaf->mViewCell->Mail();
1918	++ hits;
1919	}
1920
1921	//-- fetch the next far child from the stack
1922	if (tStack.empty())
1923	break;
1924
1925	entp = extp;
1926	mint = maxt; // NOTE: need this?
1927
1928	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1929	break;
1930
1931	BspRayTraversalData &s = tStack.top();
1932
1933	node = s.mNode;
1934	extp = s.mExitPoint;
1935	maxt = s.mMaxT;
1936
1937	tStack.pop();
1938	}
1939	}
1940
1941	return hits;
1942	}
1943
1944
1945	int BspTree::CastLineSegment(const Vector3 &origin,
1946	const Vector3 &termination,
1947	vector<ViewCell *> &viewcells)
1948	{
1949	int hits = 0;
1950	stack<BspRayTraversalData> tStack;
1951
1952	float mint = 0.0f, maxt = 1.0f;
1953
1954	Intersectable::NewMail();
1955
1956	Vector3 entp = origin;
1957	Vector3 extp = termination;
1958
1959	BspNode *node = mRoot;
1960	BspNode *farChild = NULL;
1961
1962	while (1)
1963	{
1964	if (!node->IsLeaf())
1965	{
1966	BspInterior in = dynamic_cast<BspInterior >(node);
1967
1968	Plane3 splitPlane = in->GetPlane();
1969
1970	const int entSide = splitPlane.Side(entp);
1971	const int extSide = splitPlane.Side(extp);
1972
1973	if (entSide < 0)
1974	{
1975	node = in->GetBack();
1976
1977	if(extSide <= 0) // plane does not split ray => no far child
1978	continue;
1979
1980	farChild = in->GetFront(); // plane splits ray
1981
1982	}
1983	else if (entSide > 0)
1984	{
1985	node = in->GetFront();
1986
1987	if (extSide >= 0) // plane does not split ray => no far child
1988	continue;
1989
1990	farChild = in->GetBack(); // plane splits ray
1991	}
1992	else // ray and plane are coincident
1993	{
1994	// WHAT TO DO IN THIS CASE ?
1995	//break;
1996	node = in->GetFront();
1997	continue;
1998	}
1999
2000	// push data for far child
2001	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2002
2003	// find intersection of ray segment with plane
2004	float t;
2005	extp = splitPlane.FindIntersection(origin, extp, &t);
2006	maxt *= t;
2007	}
2008	else
2009	{
2010	// reached leaf => intersection with view cell
2011	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2012
2013	if (!leaf->mViewCell->Mailed())
2014	{
2015	viewcells.push_back(leaf->mViewCell);
2016	leaf->mViewCell->Mail();
2017	hits++;
2018	}
2019
2020	//-- fetch the next far child from the stack
2021	if (tStack.empty())
2022	break;
2023
2024	entp = extp;
2025	mint = maxt; // NOTE: need this?
2026
2027	BspRayTraversalData &s = tStack.top();
2028
2029	node = s.mNode;
2030	extp = s.mExitPoint;
2031	maxt = s.mMaxT;
2032
2033	tStack.pop();
2034	}
2035	}
2036	return hits;
2037	}
2038
2039	bool BspTree::Export(const string filename)
2040	{
2041	Exporter *exporter = Exporter::GetExporter(filename);
2042
2043	if (exporter)
2044	{
2045	exporter->ExportBspTree(*this);
2046	return true;
2047	}
2048
2049	return false;
2050	}
2051
2052	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2053	{
2054	stack<BspNode *> nodeStack;
2055	nodeStack.push(mRoot);
2056
2057	ViewCell::NewMail();
2058
2059	while (!nodeStack.empty())
2060	{
2061	BspNode *node = nodeStack.top();
2062	nodeStack.pop();
2063
2064	if (node->IsLeaf())
2065	{
2066	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2067
2068	if (!viewCell->Mailed())
2069	{
2070	viewCell->Mail();
2071	viewCells.push_back(viewCell);
2072	}
2073	}
2074	else
2075	{
2076	BspInterior interior = dynamic_cast<BspInterior >(node);
2077
2078	nodeStack.push(interior->GetFront());
2079	nodeStack.push(interior->GetBack());
2080	}
2081	}
2082	}
2083
2084
2085	BspTreeStatistics &BspTree::GetStat()
2086	{
2087	return mStat;
2088	}
2089
2090
2091	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2092	{
2093	float len = 0;
2094
2095	BoundedRayContainer::const_iterator it, it_end = rays.end();
2096
2097	for (it = rays.begin(); it != it_end; ++ it)
2098	{
2099	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2100	(it)->mRay->Extrap((it)->mMaxT));
2101	}
2102
2103	return len;
2104	}
2105
2106
2107	int BspTree::SplitRays(const Plane3 &plane,
2108	BoundedRayContainer &rays,
2109	BoundedRayContainer &frontRays,
2110	BoundedRayContainer &backRays)
2111	{
2112	int splits = 0;
2113
2114	while (!rays.empty())
2115	{
2116	BoundedRay *bRay = rays.back();
2117	Ray *ray = bRay->mRay;
2118	float minT = bRay->mMinT;
2119	float maxT = bRay->mMaxT;
2120
2121	rays.pop_back();
2122
2123	Vector3 entP, extP;
2124
2125	const int cf =
2126	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2127
2128	// set id to ray classification
2129	ray->SetId(cf);
2130
2131	switch (cf)
2132	{
2133	case Ray::COINCIDENT: // TODO: should really discard ray?
2134	frontRays.push_back(bRay);
2135	//DEL_PTR(bRay);
2136	break;
2137	case Ray::BACK:
2138	backRays.push_back(bRay);
2139	break;
2140	case Ray::FRONT:
2141	frontRays.push_back(bRay);
2142	break;
2143	case Ray::FRONT_BACK:
2144	{
2145	// find intersection of ray segment with plane
2146	const float t = plane.FindT(ray->GetLoc(), extP);
2147
2148	const float newT = t * maxT;
2149
2150	frontRays.push_back(new BoundedRay(ray, minT, newT));
2151	backRays.push_back(new BoundedRay(ray, newT, maxT));
2152
2153	DEL_PTR(bRay);
2154	}
2155	break;
2156	case Ray::BACK_FRONT:
2157	{
2158	// find intersection of ray segment with plane
2159	const float t = plane.FindT(ray->GetLoc(), extP);
2160	const float newT = t * bRay->mMaxT;
2161
2162	backRays.push_back(new BoundedRay(ray, minT, newT));
2163	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2164
2165	DEL_PTR(bRay);
2166
2167	++ splits;
2168	}
2169	break;
2170	default:
2171	Debug << "Should not come here 4" << endl;
2172	break;
2173	}
2174	}
2175
2176	return splits;
2177	}
2178
2179	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2180	{
2181	BspNode *lastNode;
2182	do
2183	{
2184	lastNode = n;
2185
2186	// want to get planes defining geometry of this node => don't take
2187	// split plane of node itself
2188	n = n->GetParent();
2189
2190	if (n)
2191	{
2192	BspInterior interior = dynamic_cast<BspInterior >(n);
2193	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2194
2195	if (interior->GetFront() != lastNode)
2196	halfSpace.ReverseOrientation();
2197
2198	halfSpaces.push_back(halfSpace);
2199	}
2200	}
2201	while (n);
2202	}
2203
2204	void BspTree::ConstructGeometry(BspViewCell *vc, BspNodeGeometry &geom) const
2205	{
2206	vector<BspLeaf *> leaves = vc->mLeaves;
2207
2208	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2209
2210	for (it = leaves.begin(); it != it_end; ++ it)
2211	ConstructGeometry(*it, geom);
2212	}
2213
2214
2215	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2216	{
2217	vector<Plane3> halfSpaces;
2218	ExtractHalfSpaces(n, halfSpaces);
2219
2220	PolygonContainer candidates;
2221
2222	// bounded planes are added to the polygons (reverse polygons
2223	// as they have to be outfacing
2224	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2225	{
2226	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2227
2228	if (p->Valid(mEpsilon))
2229	{
2230	candidates.push_back(p->CreateReversePolygon());
2231	DEL_PTR(p);
2232	}
2233	}
2234
2235	// add faces of bounding box (also could be faces of the cell)
2236	for (int i = 0; i < 6; ++ i)
2237	{
2238	VertexContainer vertices;
2239
2240	for (int j = 0; j < 4; ++ j)
2241	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2242
2243	candidates.push_back(new Polygon3(vertices));
2244	}
2245
2246	for (int i = 0; i < (int)candidates.size(); ++ i)
2247	{
2248	// polygon is split by all other planes
2249	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2250	{
2251	if (i == j) // polygon and plane are coincident
2252	continue;
2253
2254	VertexContainer splitPts;
2255	Polygon3 frontPoly, backPoly;
2256
2257	const int cf = candidates[i]->
2258	ClassifyPlane(halfSpaces[j], mEpsilon);
2259
2260	switch (cf)
2261	{
2262	case Polygon3::SPLIT:
2263	frontPoly = new Polygon3();
2264	backPoly = new Polygon3();
2265
2266	candidates[i]->Split(halfSpaces[j],
2267	*frontPoly,
2268	*backPoly,
2269	mEpsilon);
2270
2271	DEL_PTR(candidates[i]);
2272
2273	if (frontPoly->Valid(mEpsilon))
2274	candidates[i] = frontPoly;
2275	else
2276	DEL_PTR(frontPoly);
2277
2278	DEL_PTR(backPoly);
2279	break;
2280	case Polygon3::BACK_SIDE:
2281	DEL_PTR(candidates[i]);
2282	break;
2283	// just take polygon as it is
2284	case Polygon3::FRONT_SIDE:
2285	case Polygon3::COINCIDENT:
2286	default:
2287	break;
2288	}
2289	}
2290
2291	if (candidates[i])
2292	geom.mPolys.push_back(candidates[i]);
2293	}
2294	}
2295
2296
2297	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2298	const bool onlyUnmailed) const
2299	{
2300	BspNodeGeometry geom;
2301	ConstructGeometry(n, geom);
2302
2303	stack<BspNode *> nodeStack;
2304	nodeStack.push(mRoot);
2305
2306	// planes needed to verify that we found neighbor leaf.
2307	vector<Plane3> halfSpaces;
2308	ExtractHalfSpaces(n, halfSpaces);
2309
2310	while (!nodeStack.empty())
2311	{
2312	BspNode *node = nodeStack.top();
2313	nodeStack.pop();
2314
2315	if (node->IsLeaf())
2316	{
2317	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2318	{
2319	// test all planes of current node if neighbour
2320	// candidate really is neighbour
2321	BspNodeGeometry candidateGeom;
2322	ConstructGeometry(node, candidateGeom);
2323
2324	bool isAdjacent = true;
2325	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2326	{
2327	const int cf =
2328	Polygon3::ClassifyPlane(candidateGeom.mPolys,
2329	halfSpaces[i],
2330	mEpsilon);
2331
2332	if (cf == Polygon3::BACK_SIDE)
2333	isAdjacent = false;
2334	}
2335
2336	if (isAdjacent)
2337	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2338	}
2339	}
2340	else
2341	{
2342	BspInterior interior = dynamic_cast<BspInterior >(node);
2343
2344	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2345	interior->mPlane,
2346	mEpsilon);
2347
2348	if (cf == Polygon3::FRONT_SIDE)
2349	nodeStack.push(interior->GetFront());
2350	else
2351	if (cf == Polygon3::BACK_SIDE)
2352	nodeStack.push(interior->GetBack());
2353	else
2354	{
2355	// random decision
2356	nodeStack.push(interior->GetBack());
2357	nodeStack.push(interior->GetFront());
2358	}
2359	}
2360	}
2361
2362	return (int)neighbors.size();
2363	}
2364
2365
2366	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2367	{
2368	stack<BspNode *> nodeStack;
2369	nodeStack.push(mRoot);
2370
2371	int mask = rand();
2372
2373	while (!nodeStack.empty())
2374	{
2375	BspNode *node = nodeStack.top();
2376	nodeStack.pop();
2377
2378	if (node->IsLeaf())
2379	{
2380	return dynamic_cast<BspLeaf *>(node);
2381	}
2382	else
2383	{
2384	BspInterior interior = dynamic_cast<BspInterior >(node);
2385	BspNode *next;
2386
2387	BspNodeGeometry geom;
2388	// todo: not very efficient: constructs full cell everytime
2389	ConstructGeometry(interior, geom);
2390
2391	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2392	halfspace,
2393	mEpsilon);
2394
2395	if (cf == Polygon3::BACK_SIDE)
2396	next = interior->GetFront();
2397	else
2398	if (cf == Polygon3::FRONT_SIDE)
2399	next = interior->GetFront();
2400	else
2401	{
2402	// random decision
2403	if (mask & 1)
2404	next = interior->GetBack();
2405	else
2406	next = interior->GetFront();
2407	mask = mask >> 1;
2408	}
2409
2410	nodeStack.push(next);
2411	}
2412	}
2413
2414	return NULL;
2415	}
2416
2417	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2418	{
2419	stack<BspNode *> nodeStack;
2420
2421	nodeStack.push(mRoot);
2422
2423	int mask = rand();
2424
2425	while (!nodeStack.empty())
2426	{
2427	BspNode *node = nodeStack.top();
2428	nodeStack.pop();
2429
2430	if (node->IsLeaf())
2431	{
2432	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2433	return dynamic_cast<BspLeaf *>(node);
2434	}
2435	else
2436	{
2437	BspInterior interior = dynamic_cast<BspInterior >(node);
2438
2439	// random decision
2440	if (mask & 1)
2441	nodeStack.push(interior->GetBack());
2442	else
2443	nodeStack.push(interior->GetFront());
2444
2445	mask = mask >> 1;
2446	}
2447	}
2448
2449	return NULL;
2450	}
2451
2452	void BspTree::AddToPvs(BspLeaf *leaf,
2453	const BoundedRayContainer &rays,
2454	int &sampleContributions,
2455	int &contributingSamples)
2456	{
2457	sampleContributions = 0;
2458	contributingSamples = 0;
2459
2460	BoundedRayContainer::const_iterator it, it_end = rays.end();
2461
2462	ViewCell *vc = leaf->GetViewCell();
2463
2464	// add contributions from samples to the PVS
2465	for (it = rays.begin(); it != it_end; ++ it)
2466	{
2467	int contribution = 0;
2468	Ray ray = (it)->mRay;
2469	float relContribution;
2470	if (!ray->intersections.empty())
2471	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject, relContribution);
2472
2473	if (ray->sourceObject.mObject)
2474	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject, relContribution);
2475
2476	if (contribution)
2477	{
2478	sampleContributions += contribution;
2479	++ contributingSamples;
2480	}
2481
2482	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2483	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2484	}
2485	}
2486
2487	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2488	{
2489	int pvsSize = 0;
2490
2491	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2492
2493	Intersectable::NewMail();
2494
2495	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2496	{
2497	Ray ray = (rit)->mRay;
2498
2499	if (!ray->intersections.empty())
2500	{
2501	if (!ray->intersections[0].mObject->Mailed())
2502	{
2503	ray->intersections[0].mObject->Mail();
2504	++ pvsSize;
2505	}
2506	}
2507	if (ray->sourceObject.mObject)
2508	{
2509	if (!ray->sourceObject.mObject->Mailed())
2510	{
2511	ray->sourceObject.mObject->Mail();
2512	++ pvsSize;
2513	}
2514	}
2515	}
2516
2517	return pvsSize;
2518	}
2519
2520	float BspTree::GetEpsilon() const
2521	{
2522	return mEpsilon;
2523	}
2524
2525
2526	/*************************************************************/
2527	/* BspNodeGeometry Implementation */
2528	/*************************************************************/
2529
2530
2531	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2532	{
2533	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2534	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2535	{
2536	Polygon3 poly = it;
2537	mPolys.push_back(new Polygon3(*poly));
2538	}
2539	}
2540
2541	BspNodeGeometry::~BspNodeGeometry()
2542	{
2543	CLEAR_CONTAINER(mPolys);
2544	}
2545
2546
2547	float BspNodeGeometry::GetArea() const
2548	{
2549	return Polygon3::GetArea(mPolys);
2550	}
2551
2552
2553	float BspNodeGeometry::GetVolume() const
2554	{
2555	//-- compute volume using tetrahedralization of the geometry
2556	// and adding the volume of the single tetrahedrons
2557	float volume = 0;
2558	const float f = 1.0f / 6.0f;
2559
2560	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2561
2562	// note: can take arbitrary point, e.g., the origin. However,
2563	// center of mass prevents precision errors
2564	const Vector3 center = CenterOfMass();
2565
2566	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2567	{
2568	Polygon3 poly = pit;
2569	const Vector3 v0 = poly->mVertices[0] - center;
2570
2571	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2572	{
2573	const Vector3 v1 = poly->mVertices[i] - center;
2574	const Vector3 v2 = poly->mVertices[i + 1] - center;
2575
2576	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2577	}
2578	}
2579
2580	return volume;
2581	}
2582
2583
2584	Vector3 BspNodeGeometry::CenterOfMass() const
2585	{
2586	int n = 0;
2587
2588	Vector3 center(0,0,0);
2589
2590	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2591
2592	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2593	{
2594	Polygon3 poly = pit;
2595
2596	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2597
2598	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2599	{
2600	center += *vit;
2601	++ n;
2602	}
2603	}
2604
2605	return center / (float)n;
2606	}
2607
2608
2609	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2610	{
2611	PolygonContainer::const_iterator it, it_end = mPolys.end();
2612
2613	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2614	{
2615	(*it)->AddToMesh(mesh);
2616	}
2617	}
2618
2619
2620	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2621	BspNodeGeometry &back,
2622	const Plane3 &splitPlane,
2623	const AxisAlignedBox3 &box,
2624	const float epsilon) const
2625	{
2626	// get cross section of new polygon
2627	Polygon3 *planePoly = box.CrossSection(splitPlane);
2628
2629	// split polygon with all other polygons
2630	planePoly = SplitPolygon(planePoly, epsilon);
2631
2632	//-- new polygon splits all other polygons
2633	for (int i = 0; i < (int)mPolys.size(); ++ i)
2634	{
2635	/// don't use epsilon here to get exact split planes
2636	const int cf =
2637	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2638
2639	switch (cf)
2640	{
2641	case Polygon3::SPLIT:
2642	{
2643	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2644
2645	Polygon3 *frontPoly = new Polygon3();
2646	Polygon3 *backPoly = new Polygon3();
2647
2648	poly->Split(splitPlane,
2649	*frontPoly,
2650	*backPoly,
2651	epsilon);
2652
2653	DEL_PTR(poly);
2654
2655	if (frontPoly->Valid(epsilon))
2656	front.mPolys.push_back(frontPoly);
2657	else
2658	DEL_PTR(frontPoly);
2659
2660	if (backPoly->Valid(epsilon))
2661	back.mPolys.push_back(backPoly);
2662	else
2663	DEL_PTR(backPoly);
2664	}
2665
2666	break;
2667	case Polygon3::BACK_SIDE:
2668	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2669	break;
2670	case Polygon3::FRONT_SIDE:
2671	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2672	break;
2673	case Polygon3::COINCIDENT:
2674	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2675	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2676	break;
2677	default:
2678	break;
2679	}
2680	}
2681
2682	//-- finally add the new polygon to the child node geometries
2683	if (planePoly)
2684	{
2685	// add polygon with normal pointing into positive half space to back cell
2686	back.mPolys.push_back(planePoly);
2687	// add polygon with reverse orientation to front cell
2688	front.mPolys.push_back(planePoly->CreateReversePolygon());
2689	}
2690
2691	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2692	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2693	}
2694
2695	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2696	const float epsilon) const
2697	{
2698	if (!planePoly->Valid(epsilon))
2699	DEL_PTR(planePoly);
2700
2701	// polygon is split by all other planes
2702	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2703	{
2704	Plane3 plane = mPolys[i]->GetSupportingPlane();
2705
2706	/// don't use epsilon here to get exact split planes
2707	const int cf =
2708	planePoly->ClassifyPlane(plane, Limits::Small);
2709
2710	// split new polygon with all previous planes
2711	switch (cf)
2712	{
2713	case Polygon3::SPLIT:
2714	{
2715	Polygon3 *frontPoly = new Polygon3();
2716	Polygon3 *backPoly = new Polygon3();
2717
2718	planePoly->Split(plane,
2719	*frontPoly,
2720	*backPoly,
2721	epsilon);
2722
2723	// don't need anymore
2724	DEL_PTR(planePoly);
2725	DEL_PTR(frontPoly);
2726
2727	// back polygon is belonging to geometry
2728	if (backPoly->Valid(epsilon))
2729	planePoly = backPoly;
2730	else
2731	DEL_PTR(backPoly);
2732	}
2733	break;
2734	case Polygon3::FRONT_SIDE:
2735	DEL_PTR(planePoly);
2736	break;
2737	// polygon is taken as it is
2738	case Polygon3::BACK_SIDE:
2739	case Polygon3::COINCIDENT:
2740	default:
2741	break;
2742	}
2743	}
2744
2745	return planePoly;
2746	}
2747
2748
2749	ViewCell *
2750	BspTree::GetViewCell(const Vector3 &point)
2751	{
2752	if (mRoot == NULL)
2753	return NULL;
2754
2755
2756	stack<BspNode *> nodeStack;
2757	nodeStack.push(mRoot);
2758
2759	ViewCell *viewcell = NULL;
2760
2761	while (!nodeStack.empty()) {
2762	BspNode *node = nodeStack.top();
2763	nodeStack.pop();
2764
2765	if (node->IsLeaf()) {
2766	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
2767	break;
2768	} else {
2769
2770	BspInterior interior = dynamic_cast<BspInterior >(node);
2771
2772	// random decision
2773	if (interior->GetPlane().Side(point) < 0)
2774	nodeStack.push(interior->GetBack());
2775	else
2776	nodeStack.push(interior->GetFront());
2777	}
2778	}
2779
2780	return viewcell;
2781	}
2782
2783	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
2784	{
2785	Polygon3::IncludeInBox(mPolys, box);
2786	}

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