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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 452

Revision 452, 62.4 KB checked in by mattausch, 19 years ago (diff)
started to add view cell merging to vsp kd tree

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

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