Context Navigation

source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 436

Revision 436, 63.8 KB checked in by mattausch, 19 years ago (diff)
bsptree view cells working in VssPreprocessor?

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::sConstructionMethod = FROM_INPUT_VIEW_CELLS;
39
40	int BspTree::sFrontId = 0;
41	int BspTree::sBackId = 0;
42	int BspTree::sFrontAndBackId = 0;
43
44	/****************************************************************/
45	/* class BspNode implementation */
46	/****************************************************************/
47
48	BspNode::BspNode():
49	mParent(NULL)
50	{}
51
52	BspNode::BspNode(BspInterior *parent):
53	mParent(parent)
54	{}
55
56
57	bool BspNode::IsRoot() const
58	{
59	return mParent == NULL;
60	}
61
62	BspInterior *BspNode::GetParent()
63	{
64	return mParent;
65	}
66
67	void BspNode::SetParent(BspInterior *parent)
68	{
69	mParent = parent;
70	}
71
72	/****************************************************************/
73	/* class BspInterior implementation */
74	/****************************************************************/
75
76
77	BspInterior::BspInterior(const Plane3 &plane):
78	mPlane(plane), mFront(NULL), mBack(NULL)
79	{}
80
81	BspInterior::~BspInterior()
82	{
83	DEL_PTR(mFront);
84	DEL_PTR(mBack);
85	}
86
87	bool BspInterior::IsLeaf() const
88	{
89	return false;
90	}
91
92	BspNode *BspInterior::GetBack()
93	{
94	return mBack;
95	}
96
97	BspNode *BspInterior::GetFront()
98	{
99	return mFront;
100	}
101
102	Plane3 *BspInterior::GetPlane()
103	{
104	return &mPlane;
105	}
106
107	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
108	{
109	if (mBack == oldChild)
110	mBack = newChild;
111	else
112	mFront = newChild;
113	}
114
115	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
116	{
117	mBack = b;
118	mFront = f;
119	}
120
121	int BspInterior::SplitPolygons(PolygonContainer &polys,
122	PolygonContainer &frontPolys,
123	PolygonContainer &backPolys,
124	PolygonContainer &coincident)
125	{
126	Polygon3 *splitPoly = NULL;
127
128	int splits = 0;
129
130	#ifdef _Debug
131	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
132	#endif
133	while (!polys.empty())
134	{
135	Polygon3 *poly = polys.back();
136	polys.pop_back();
137
138	//Debug << "New polygon with plane: " << poly->GetSupportingPlane() << "\n";
139
140	// classify polygon
141	const int cf = poly->ClassifyPlane(mPlane);
142
143	Polygon3 *front_piece = NULL;
144	Polygon3 *back_piece = NULL;
145
146	switch (cf)
147	{
148	case Polygon3::COINCIDENT:
149	coincident.push_back(poly);
150	break;
151	case Polygon3::FRONT_SIDE:
152	frontPolys.push_back(poly);
153	break;
154	case Polygon3::BACK_SIDE:
155	backPolys.push_back(poly);
156	break;
157	case Polygon3::SPLIT:
158	front_piece = new Polygon3(poly->mParent);
159	back_piece = new Polygon3(poly->mParent);
160
161	//-- split polygon into front and back part
162	poly->Split(mPlane,
163	*front_piece,
164	*back_piece);
165
166	++ splits; // increase number of splits
167
168	//-- inherit rays from parent polygon for blocked ray criterium
169	poly->InheritRays(front_piece, back_piece);
170	//Debug << "p: " << poly->mPiercingRays.size() << " f: " << front_piece->mPiercingRays.size() << " b: " << back_piece->mPiercingRays.size() << endl;
171
172	// check if polygons still valid
173	if (front_piece->Valid())
174	frontPolys.push_back(front_piece);
175	else
176	DEL_PTR(front_piece);
177
178	if (back_piece->Valid())
179	backPolys.push_back(back_piece);
180	else
181	DEL_PTR(back_piece);
182
183	#ifdef _DEBUG
184	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
185	#endif
186	DEL_PTR(poly);
187	break;
188	default:
189	Debug << "SHOULD NEVER COME HERE\n";
190	break;
191	}
192	}
193
194	return splits;
195	}
196
197	/****************************************************************/
198	/* class BspLeaf implementation */
199	/****************************************************************/
200	BspLeaf::BspLeaf(): mViewCell(NULL)
201	{
202	}
203
204	BspLeaf::BspLeaf(BspViewCell *viewCell):
205	mViewCell(viewCell)
206	{
207	}
208
209	BspLeaf::BspLeaf(BspInterior *parent):
210	BspNode(parent), mViewCell(NULL)
211	{}
212
213	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
214	BspNode(parent), mViewCell(viewCell)
215	{
216	}
217
218	BspViewCell *BspLeaf::GetViewCell() const
219	{
220	return mViewCell;
221	}
222
223	void BspLeaf::SetViewCell(BspViewCell *viewCell)
224	{
225	mViewCell = viewCell;
226	}
227
228	bool BspLeaf::IsLeaf() const
229	{
230	return true;
231	}
232
233	void BspLeaf::AddToPvs(const BoundedRayContainer &rays,
234	int &sampleContributions,
235	int &contributingSamples,
236	bool storeLeavesWithRays)
237	{
238	sampleContributions = 0;
239	contributingSamples = 0;
240
241	BoundedRayContainer::const_iterator it, it_end = rays.end();
242
243	// add contributions from samples to the PVS
244	for (it = rays.begin(); it != it_end; ++ it)
245	{
246	int contribution = 0;
247	Ray ray = (it)->mRay;
248
249	if (!ray->intersections.empty())
250	contribution += mViewCell->GetPvs().AddSample(ray->intersections[0].mObject);
251
252	if (ray->sourceObject.mObject)
253	contribution += mViewCell->GetPvs().AddSample(ray->sourceObject.mObject);
254
255	if (contribution > 0)
256	{
257	sampleContributions += contribution;
258	++ contributingSamples;
259	}
260
261	if (storeLeavesWithRays)
262	// warning: intersections not ordered
263	ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
264	}
265	}
266
267
268	/****************************************************************/
269	/* class BspTree implementation */
270	/****************************************************************/
271
272	BspTree::BspTree(BspViewCell *viewCell):
273	mRootCell(viewCell),
274	mRoot(NULL),
275	mGenerateViewCells(false),
276	mStoreLeavesWithRays(false),
277	mPvsUseArea(true)
278	{
279	Randomize(); // initialise random generator for heuristics
280
281	//-- termination criteria for autopartition
282	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
283	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
284	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
285	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
286	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
287	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
288	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
289
290	//-- factors for bsp tree split plane heuristics
291	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
292	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
293	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
294	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
295	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
296	environment->GetFloatValue("BspTree.Factor.pvsFactor", mPvsFactor);
297	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
298	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
299	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
300	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
301
302	//-- termination criteria for axis aligned split
303	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAaCtDivCi);
304	environment->GetFloatValue("BspTree.Termination.AxisAligned.maxCostRatio", mMaxCostRatio);
305	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
306	mTermMinPolysForAxisAligned);
307	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
308	mTermMinRaysForAxisAligned);
309	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
310	mTermMinObjectsForAxisAligned);
311	//-- partition criteria
312	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
313	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
314	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
315	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
316
317	environment->GetFloatValue("BspTree.Construction.sideTolerance", Vector3::sDistTolerance);
318	Vector3::sDistToleranceSqrt = Vector3::sDistTolerance * Vector3::sDistTolerance;
319
320	// post processing stuff
321	environment->GetIntValue("ViewCells.PostProcessing.minPvsDif", mMinPvsDif);
322	environment->GetIntValue("ViewCells.PostProcessing.minPvs", mMinPvs);
323	environment->GetIntValue("ViewCells.PostProcessing.maxPvs", mMaxPvs);
324
325	Debug << "BSP max depth: " << mTermMaxDepth << endl;
326	Debug << "BSP min PVS: " << mTermMinPvs << endl;
327	Debug << "BSP min area: " << mTermMinArea << endl;
328	Debug << "BSP max polys: " << mTermMinPolys << endl;
329	Debug << "BSP max rays: " << mTermMinRays << endl;
330	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
331	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
332
333	Debug << "Split plane strategy: ";
334	if (mSplitPlaneStrategy & RANDOM_POLYGON)
335	Debug << "random polygon ";
336	if (mSplitPlaneStrategy & AXIS_ALIGNED)
337	Debug << "axis aligned ";
338	if (mSplitPlaneStrategy & LEAST_SPLITS)
339	Debug << "least splits ";
340	if (mSplitPlaneStrategy & BALANCED_POLYS)
341	Debug << "balanced polygons ";
342	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
343	Debug << "balanced view cells ";
344	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
345	Debug << "largest polygon area ";
346	if (mSplitPlaneStrategy & VERTICAL_AXIS)
347	Debug << "vertical axis ";
348	if (mSplitPlaneStrategy & BLOCKED_RAYS)
349	Debug << "blocked rays ";
350	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
351	Debug << "least ray splits ";
352	if (mSplitPlaneStrategy & BALANCED_RAYS)
353	Debug << "balanced rays ";
354	if (mSplitPlaneStrategy & PVS)
355	Debug << "pvs";
356
357	Debug << endl;
358	}
359
360	void BspTree::ParseEnvironment()
361	{
362	//-- parse bsp cell tree construction method
363	char constructionMethodStr[60];
364
365	environment->GetStringValue("BspTree.Construction.input", constructionMethodStr);
366
367	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
368
369	if (strcmp(constructionMethodStr, "fromViewCells") == 0)
370	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
371	else if (strcmp(constructionMethodStr, "fromSceneGeometry") == 0)
372	sConstructionMethod = FROM_SCENE_GEOMETRY;
373	else if (strcmp(constructionMethodStr, "fromSamples") == 0)
374	sConstructionMethod = FROM_SAMPLES;
375	else
376	{
377	cerr << "Wrong construction method " << constructionMethodStr << endl;
378	exit(1);
379	}
380
381	Debug << "Construction method: " << constructionMethodStr << endl;
382	}
383
384	const BspTreeStatistics &BspTree::GetStatistics() const
385	{
386	return mStat;
387	}
388
389	void BspTreeStatistics::Print(ostream &app) const
390	{
391	app << "===== BspTree statistics ===============\n";
392
393	app << setprecision(4);
394
395	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
396
397	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
398
399	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
400
401	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
402
403	app << "#N_SPLITS ( Number of splits )\n" << splits << "\n";
404
405	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
406	<< maxDepthNodes * 100 / (double)Leaves() << endl;
407
408	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
409	<< maxDepthNodes * 100 / (double)Leaves() << endl;
410
411	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
412	<< minPvsNodes * 100 / (double)Leaves() << endl;
413
414	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
415	<< minRaysNodes * 100 / (double)Leaves() << endl;
416
417	app << "#N_PMINAREALEAVES ( Percentage of leaves with mininum area )\n"
418	<< minAreaNodes * 100 / (double)Leaves() << endl;
419
420	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
421	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
422
423	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
424
425	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
426
427	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
428
429	app << "#N_INPUT_POLYGONS (number of input polygons )\n" << polys << endl;
430
431	//app << "#N_PVS: " << pvs << endl;
432
433	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
434	(polys + splits) / (double)polys << endl;
435
436	app << "===== END OF BspTree statistics ==========\n";
437	}
438
439
440	BspTree::~BspTree()
441	{
442	DEL_PTR(mRoot);
443	}
444
445	void BspTree::InsertViewCell(ViewCell *viewCell)
446	{
447	PolygonContainer *polys = new PolygonContainer();
448
449	// extract polygons that guide the split process
450	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
451	mBox.Include(viewCell->GetBox()); // add to BSP aabb
452
453	InsertPolygons(polys);
454	}
455
456	void BspTree::InsertPolygons(PolygonContainer *polys)
457	{
458	std::stack<BspTraversalData> tStack;
459
460	// traverse existing tree or create new tree
461	if (!mRoot)
462	mRoot = new BspLeaf();
463
464	tStack.push(BspTraversalData(mRoot, polys, 0, mRootCell, new BoundedRayContainer(), 0,
465	mBox.SurfaceArea(), new BspNodeGeometry()));
466
467	while (!tStack.empty())
468	{
469	// filter polygons donw the tree
470	BspTraversalData tData = tStack.top();
471	tStack.pop();
472
473	if (!tData.mNode->IsLeaf())
474	{
475	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
476
477	//-- filter view cell polygons down the tree until a leaf is reached
478	if (!tData.mPolygons->empty())
479	{
480	PolygonContainer *frontPolys = new PolygonContainer();
481	PolygonContainer *backPolys = new PolygonContainer();
482	PolygonContainer coincident;
483
484	int splits = 0;
485
486	// split viewcell polygons with respect to split plane
487	splits += interior->SplitPolygons(*tData.mPolygons,
488	*frontPolys,
489	*backPolys,
490	coincident);
491
492	// extract view cells associated with the split polygons
493	ViewCell *frontViewCell = mRootCell;
494	ViewCell *backViewCell = mRootCell;
495
496	BspTraversalData frontData(interior->GetFront(),
497	frontPolys,
498	tData.mDepth + 1,
499	mRootCell,
500	tData.mRays,
501	tData.mPvs,
502	mBox.SurfaceArea(),
503	new BspNodeGeometry());
504
505	BspTraversalData backData(interior->GetBack(),
506	backPolys,
507	tData.mDepth + 1,
508	mRootCell,
509	tData.mRays,
510	tData.mPvs,
511	mBox.SurfaceArea(),
512	new BspNodeGeometry());
513
514	if (!mGenerateViewCells)
515	{
516	ExtractViewCells(frontData,
517	backData,
518	coincident,
519	interior->mPlane);
520	}
521
522	// don't need coincident polygons anymore
523	CLEAR_CONTAINER(coincident);
524
525	mStat.splits += splits;
526
527	// push the children on the stack
528	tStack.push(frontData);
529	tStack.push(backData);
530	}
531
532	// cleanup
533	DEL_PTR(tData.mPolygons);
534	}
535	else
536	{
537	// reached leaf => subdivide current viewcell
538	BspNode *subRoot = Subdivide(tStack, tData);
539	}
540	}
541	}
542
543	int BspTree::AddMeshToPolygons(Mesh mesh, PolygonContainer &polys, MeshInstance parent)
544	{
545	FaceContainer::const_iterator fi;
546
547	// copy the face data to polygons
548	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
549	{
550	Polygon3 poly = new Polygon3((fi), mesh);
551
552	if (poly->Valid())
553	{
554	poly->mParent = parent; // set parent intersectable
555	polys.push_back(poly);
556	}
557	else
558	DEL_PTR(poly);
559	}
560	return (int)mesh->mFaces.size();
561	}
562
563	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
564	PolygonContainer &polys,
565	int maxObjects)
566	{
567	int limit = (maxObjects > 0) ?
568	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
569
570	int polysSize = 0;
571
572	for (int i = 0; i < limit; ++ i)
573	{
574	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
575	{
576	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
577	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
578	}
579	}
580
581	return polysSize;
582	}
583
584	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
585	{
586	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
587
588	for (int i = 0; i < limit; ++i)
589	{
590	Intersectable object = objects[i];//it;
591	Mesh *mesh = NULL;
592
593	switch (object->Type()) // extract the meshes
594	{
595	case Intersectable::MESH_INSTANCE:
596	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
597	break;
598	case Intersectable::VIEW_CELL:
599	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
600	break;
601	// TODO: handle transformed mesh instances
602	default:
603	Debug << "intersectable type not supported" << endl;
604	break;
605	}
606
607	if (mesh) // copy the mesh data to polygons
608	{
609	mBox.Include(object->GetBox()); // add to BSP tree aabb
610	AddMeshToPolygons(mesh, polys, mRootCell);
611	}
612	}
613
614	return (int)polys.size();
615	}
616
617	void BspTree::Construct(const ViewCellContainer &viewCells)
618	{
619	mStat.nodes = 1;
620	mBox.Initialize(); // initialise bsp tree bounding box
621
622	// copy view cell meshes into one big polygon soup
623	PolygonContainer *polys = new PolygonContainer();
624	mStat.polys = AddToPolygonSoup(viewCells, *polys);
625
626	// construct tree from the view cell polygons
627	Construct(polys, new BoundedRayContainer());
628	}
629
630
631	void BspTree::Construct(const ObjectContainer &objects)
632	{
633	mStat.nodes = 1;
634	mBox.Initialize(); // initialise bsp tree bounding box
635
636	PolygonContainer *polys = new PolygonContainer();
637
638	// copy mesh instance polygons into one big polygon soup
639	mStat.polys = AddToPolygonSoup(objects, *polys);
640
641	// construct tree from polygon soup
642	Construct(polys, new BoundedRayContainer());
643	}
644
645	void BspTree::Construct(const RayContainer &sampleRays)
646	{
647	mStat.nodes = 1;
648	mBox.Initialize(); // initialise BSP tree bounding box
649
650	PolygonContainer *polys = new PolygonContainer();
651	BoundedRayContainer *rays = new BoundedRayContainer();
652
653	RayContainer::const_iterator rit, rit_end = sampleRays.end();
654
655	long startTime = GetTime();
656
657	Debug << "** Extracting polygons from rays **\n";
658
659	std::map<Face , Polygon3 > facePolyMap;
660
661	//-- extract polygons intersected by the rays
662	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
663	{
664	Ray ray = rit;
665
666	// get ray-face intersection. Store polygon representing the rays together
667	// with rays intersecting the face.
668	if (!ray->intersections.empty())
669	{
670	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
671	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
672
673	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
674
675	if (it != facePolyMap.end())
676	{
677	//store rays if needed for heuristics
678	if (mSplitPlaneStrategy & BLOCKED_RAYS)
679	(*it).second->mPiercingRays.push_back(ray);
680	}
681	else
682	{ //store rays if needed for heuristics
683	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
684	poly->mParent = obj;
685	polys->push_back(poly);
686
687	if (mSplitPlaneStrategy & BLOCKED_RAYS)
688	poly->mPiercingRays.push_back(ray);
689
690	facePolyMap[face] = poly;
691	}
692	}
693	}
694
695	facePolyMap.clear();
696
697	// compute bounding box
698	Polygon3::IncludeInBox(*polys, mBox);
699
700	//-- store rays
701	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
702	{
703	Ray ray = rit;
704	ray->SetId(-1); // reset id
705
706	float minT, maxT;
707	if (BoundRay(*ray, minT, maxT))
708	rays->push_back(new BoundedRay(ray, minT, maxT));
709	}
710
711	mStat.polys = (int)polys->size();
712
713	Debug << "** Finished polygon extraction **" << endl;
714	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
715	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
716
717	Construct(polys, rays);
718	}
719
720	void BspTree::Construct(const ObjectContainer &objects, const RayContainer &sampleRays)
721	{
722	mStat.nodes = 1;
723	mBox.Initialize(); // initialise BSP tree bounding box
724
725	BoundedRayContainer *rays = new BoundedRayContainer();
726	PolygonContainer *polys = new PolygonContainer();
727
728	// copy mesh instance polygons into one big polygon soup
729	mStat.polys = AddToPolygonSoup(objects, *polys);
730
731	RayContainer::const_iterator rit, rit_end = sampleRays.end();
732
733	//-- store rays
734	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
735	{
736	Ray ray = rit;
737	ray->SetId(-1); // reset id
738
739	float minT, maxT;
740	if (BoundRay(*ray, minT, maxT))
741	rays->push_back(new BoundedRay(ray, minT, maxT));
742	}
743
744	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
745	Construct(polys, rays);
746	}
747
748	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
749	{
750	std::stack<BspTraversalData> tStack;
751
752	mRoot = new BspLeaf();
753
754	BspNodeGeometry *cell = new BspNodeGeometry();
755	ConstructGeometry(mRoot, *cell);
756
757	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
758	ComputePvsSize(*rays), cell->GetArea(), cell);
759
760	tStack.push(tData);
761
762	mStat.Start();
763	cout << "Contructing bsp tree ... ";
764	long startTime = GetTime();
765	while (!tStack.empty())
766	{
767	tData = tStack.top();
768
769	tStack.pop();
770
771	// subdivide leaf node
772	BspNode *r = Subdivide(tStack, tData);
773
774	if (r == mRoot)
775	Debug << "BSP tree construction time spent at root: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
776	}
777
778	cout << "finished\n";
779
780	mStat.Stop();
781	}
782
783	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
784	{
785	return
786	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
787	((int)data.mRays->size() <= mTermMinRays) \|\|
788	(data.mPvs <= mTermMinPvs) \|\|
789	(data.mArea <= mTermMinArea) \|\|
790	(data.mDepth >= mTermMaxDepth) \|\|
791	(data.GetAvgRayContribution() < mTermMaxRayContribution));
792	}
793
794	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
795	{
796	//-- terminate traversal
797	if (TerminationCriteriaMet(tData))
798	{
799	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
800
801	BspViewCell *viewCell;
802
803	// generate new view cell for each leaf
804	if (mGenerateViewCells)
805	{
806	viewCell = dynamic_cast<BspViewCell *>(ViewCell::Generate());
807	}
808	else
809	{
810	// add view cell to leaf
811	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
812	}
813
814	leaf->SetViewCell(viewCell);
815	viewCell->mBspLeaves.push_back(leaf);
816
817	//-- add pvs
818	if (viewCell != mRootCell)
819	{
820	int conSamp = 0, sampCon = 0;
821	leaf->AddToPvs(*tData.mRays, conSamp, sampCon);
822
823	mStat.contributingSamples += conSamp;
824	mStat.sampleContributions += sampCon;
825	}
826
827	EvaluateLeafStats(tData);
828
829	//-- clean up
830
831	// discard polygons
832	CLEAR_CONTAINER(*tData.mPolygons);
833	// discard rays
834	CLEAR_CONTAINER(*tData.mRays);
835
836	DEL_PTR(tData.mPolygons);
837	DEL_PTR(tData.mRays);
838	DEL_PTR(tData.mGeometry);
839
840	return leaf;
841	}
842
843	//-- continue subdivision
844	PolygonContainer coincident;
845
846	PolygonContainer *frontPolys = new PolygonContainer();
847	PolygonContainer *backPolys = new PolygonContainer();
848
849	BoundedRayContainer *frontRays = new BoundedRayContainer();
850	BoundedRayContainer *backRays = new BoundedRayContainer();
851
852	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
853	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
854	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
855	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
856
857	// create new interior node and two leaf nodes
858	BspInterior *interior = SubdivideNode(tData,
859	tFrontData,
860	tBackData,
861	coincident);
862
863	#ifdef _DEBUG
864	if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
865	{ for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
866	Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
867	Debug << endl;}
868	#endif
869
870	// extract view cells from coincident polygons according to plane normal
871	// only if front or back polygons are empty
872	if (!mGenerateViewCells)
873	{
874	ExtractViewCells(tFrontData,
875	tBackData,
876	coincident,
877	interior->mPlane);
878	}
879
880	// don't need coincident polygons anymory
881	CLEAR_CONTAINER(coincident);
882
883	// push the children on the stack
884	tStack.push(tFrontData);
885	tStack.push(tBackData);
886
887	// cleanup
888	DEL_PTR(tData.mNode);
889	DEL_PTR(tData.mPolygons);
890	DEL_PTR(tData.mRays);
891	DEL_PTR(tData.mGeometry);
892
893	return interior;
894	}
895
896	void BspTree::ExtractViewCells(BspTraversalData &frontData,
897	BspTraversalData &backData,
898	const PolygonContainer &coincident,
899	const Plane3 splitPlane) const
900	{
901	// if not empty, tree is further subdivided => don't have to find view cell
902	bool foundFront = !frontData.mPolygons->empty();
903	bool foundBack = !frontData.mPolygons->empty();
904
905	PolygonContainer::const_iterator it =
906	coincident.begin(), it_end = coincident.end();
907
908	//-- find first view cells in front and back leafs
909	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
910	{
911	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
912	{
913	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
914	foundBack = true;
915	}
916	else
917	{
918	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
919	foundFront = true;
920	}
921	}
922	}
923
924	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
925	BspTraversalData &frontData,
926	BspTraversalData &backData,
927	PolygonContainer &coincident)
928	{
929	mStat.nodes += 2;
930
931	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
932	// select subdivision plane
933	BspInterior *interior =
934	new BspInterior(SelectPlane(leaf, tData));
935
936	#ifdef _DEBUG
937	Debug << interior << endl;
938	#endif
939
940	// subdivide rays into front and back rays
941	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
942
943	// subdivide polygons with plane
944	mStat.splits += interior->SplitPolygons(*tData.mPolygons,
945	*frontData.mPolygons,
946	*backData.mPolygons,
947	coincident);
948
949	// compute pvs
950	frontData.mPvs = ComputePvsSize(*frontData.mRays);
951	backData.mPvs = ComputePvsSize(*backData.mRays);
952
953	// split geometry and compute area
954	if (1)
955	{
956	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
957	*backData.mGeometry,
958	*this,
959	interior->mPlane);
960
961
962	frontData.mArea = frontData.mGeometry->GetArea();
963	backData.mArea = backData.mGeometry->GetArea();
964	}
965
966	// compute accumulated ray length
967	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
968	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
969
970	//-- create front and back leaf
971
972	BspInterior *parent = leaf->GetParent();
973
974	// replace a link from node's parent
975	if (!leaf->IsRoot())
976	{
977	parent->ReplaceChildLink(leaf, interior);
978	interior->SetParent(parent);
979	}
980	else // new root
981	{
982	mRoot = interior;
983	}
984
985	// and setup child links
986	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
987
988	frontData.mNode = interior->mFront;
989	backData.mNode = interior->mBack;
990
991	//DEL_PTR(leaf);
992	return interior;
993	}
994
995	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
996	const int axis,
997	vector<SortableEntry> &splitCandidates) const
998	{
999	splitCandidates.clear();
1000
1001	int requestedSize = 2 * (int)polys.size();
1002	// creates a sorted split candidates array
1003	splitCandidates.reserve(requestedSize);
1004
1005	PolygonContainer::const_iterator it, it_end = polys.end();
1006
1007	AxisAlignedBox3 box;
1008
1009	// insert all queries
1010	for(it = polys.begin(); it != it_end; ++ it)
1011	{
1012	box.Initialize();
1013	box.Include((it));
1014
1015	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1016	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1017	}
1018
1019	stable_sort(splitCandidates.begin(), splitCandidates.end());
1020	}
1021
1022
1023	float BspTree::BestCostRatio(const PolygonContainer &polys,
1024	const AxisAlignedBox3 &box,
1025	const int axis,
1026	float &position,
1027	int &objectsBack,
1028	int &objectsFront) const
1029	{
1030	vector<SortableEntry> splitCandidates;
1031
1032	SortSplitCandidates(polys, axis, splitCandidates);
1033
1034	// go through the lists, count the number of objects left and right
1035	// and evaluate the following cost funcion:
1036	// C = ct_div_ci + (ol + or)/queries
1037
1038	int objectsLeft = 0, objectsRight = (int)polys.size();
1039
1040	float minBox = box.Min(axis);
1041	float maxBox = box.Max(axis);
1042	float boxArea = box.SurfaceArea();
1043
1044	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1045	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1046
1047	float minSum = 1e20f;
1048	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1049
1050	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1051	{
1052	switch ((*ci).type)
1053	{
1054	case SortableEntry::POLY_MIN:
1055	++ objectsLeft;
1056	break;
1057	case SortableEntry::POLY_MAX:
1058	-- objectsRight;
1059	break;
1060	default:
1061	break;
1062	}
1063
1064	if ((ci).value > minBand && (ci).value < maxBand)
1065	{
1066	AxisAlignedBox3 lbox = box;
1067	AxisAlignedBox3 rbox = box;
1068	lbox.SetMax(axis, (*ci).value);
1069	rbox.SetMin(axis, (*ci).value);
1070
1071	float sum = objectsLeft * lbox.SurfaceArea() +
1072	objectsRight * rbox.SurfaceArea();
1073
1074	if (sum < minSum)
1075	{
1076	minSum = sum;
1077	position = (*ci).value;
1078
1079	objectsBack = objectsLeft;
1080	objectsFront = objectsRight;
1081	}
1082	}
1083	}
1084
1085	float oldCost = (float)polys.size();
1086	float newCost = mAaCtDivCi + minSum / boxArea;
1087	float ratio = newCost / oldCost;
1088
1089
1090	#if 0
1091	Debug << "====================" << endl;
1092	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1093	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1094	#endif
1095	return ratio;
1096	}
1097
1098	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1099	const PolygonContainer &polys) const
1100	{
1101	AxisAlignedBox3 box;
1102	box.Initialize();
1103
1104	// create bounding box of region
1105	Polygon3::IncludeInBox(polys, box);
1106
1107	int objectsBack = 0, objectsFront = 0;
1108	int axis = 0;
1109	float costRatio = MAX_FLOAT;
1110	Vector3 position;
1111
1112	//-- area subdivision
1113	for (int i = 0; i < 3; ++ i)
1114	{
1115	float p = 0;
1116	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1117
1118	if (r < costRatio)
1119	{
1120	costRatio = r;
1121	axis = i;
1122	position = p;
1123	}
1124	}
1125
1126	if (costRatio >= mMaxCostRatio)
1127	return false;
1128
1129	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1130	plane = Plane3(norm, position);
1131
1132	return true;
1133	}
1134
1135	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1136	{
1137	if (data.mPolygons->empty() && data.mRays->empty())
1138	{
1139	Debug << "Warning: No autopartition polygon candidate available\n";
1140
1141	// return axis aligned split
1142	AxisAlignedBox3 box;
1143	box.Initialize();
1144
1145	// create bounding box of region
1146	Polygon3::IncludeInBox(*data.mPolygons, box);
1147
1148	const int axis = box.Size().DrivingAxis();
1149	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1150
1151	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1152	return Plane3(norm, position);
1153	}
1154
1155	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1156	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1157	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1158	((mTermMinObjectsForAxisAligned < 0) \|\|
1159	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1160	{
1161	Plane3 plane;
1162	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1163	return plane;
1164	}
1165
1166	// simplest strategy: just take next polygon
1167	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1168	{
1169	if (!data.mPolygons->empty())
1170	{
1171	Polygon3 nextPoly = (data.mPolygons)[Random((int)data.mPolygons->size())];
1172	return nextPoly->GetSupportingPlane();
1173	}
1174	else
1175	{
1176	const int candidateIdx = Random((int)data.mRays->size());
1177	BoundedRay bRay = (data.mRays)[candidateIdx];
1178
1179	Ray *ray = bRay->mRay;
1180
1181	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1182	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1183
1184	const Vector3 pt = (maxPt + minPt) * 0.5;
1185
1186	const Vector3 normal = ray->GetDir();
1187
1188	return Plane3(normal, pt);
1189	}
1190
1191	return Plane3();
1192	}
1193
1194	// use heuristics to find appropriate plane
1195	return SelectPlaneHeuristics(leaf, data);
1196	}
1197
1198	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1199	{
1200	float lowestCost = MAX_FLOAT;
1201	Plane3 bestPlane;
1202	Plane3 plane;
1203
1204	int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1205
1206	int candidateIdx = limit;
1207
1208	for (int i = 0; i < limit; ++ i)
1209	{
1210	candidateIdx = GetNextCandidateIdx(candidateIdx, *data.mPolygons);
1211
1212	Polygon3 poly = (data.mPolygons)[candidateIdx];
1213	// evaluate current candidate
1214	const float candidateCost =
1215	SplitPlaneCost(poly->GetSupportingPlane(), data);
1216
1217	if (candidateCost < lowestCost)
1218	{
1219	bestPlane = poly->GetSupportingPlane();
1220	lowestCost = candidateCost;
1221	}
1222	}
1223
1224	//Debug << "lowest: " << lowestCost << endl;
1225
1226	//-- choose candidate planes extracted from rays
1227	// we currently use two methods
1228	// 1) take 3 ray endpoints, where two are minimum and one a maximum
1229	// point or the other way round
1230	// 2) take plane normal as plane normal and the midpoint of the ray.
1231	// PROBLEM: does not resemble any point where visibility is likely to change
1232	const BoundedRayContainer *rays = data.mRays;
1233
1234	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1235	{
1236	candidateIdx = Random((int)rays->size());
1237	BoundedRay bRay = (rays)[candidateIdx];
1238
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	plane = Plane3(normal, pt);
1249
1250	const float candidateCost = SplitPlaneCost(plane, data);
1251
1252	if (candidateCost < lowestCost)
1253	{
1254	bestPlane = plane;
1255
1256	lowestCost = candidateCost;
1257	}
1258	}
1259
1260	//Debug << "lowest: " << lowestCost << endl;
1261	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1262	{
1263	Vector3 pt[3];
1264	int idx[3];
1265	int cmaxT = 0;
1266	int cminT = 0;
1267	bool chooseMin = false;
1268
1269	for (int j = 0; j < 3; j ++)
1270	{
1271	idx[j] = Random((int)rays->size() * 2);
1272
1273	if (idx[j] >= (int)rays->size())
1274	{
1275	idx[j] -= (int)rays->size();
1276
1277	chooseMin = (cminT < 2);
1278	}
1279	else
1280	chooseMin = (cmaxT < 2);
1281
1282	BoundedRay bRay = (rays)[idx[j]];
1283	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) : bRay->mRay->Extrap(bRay->mMaxT);
1284	}
1285
1286	plane = Plane3(pt[0], pt[1], pt[2]);
1287
1288	const float candidateCost = SplitPlaneCost(plane, data);
1289
1290	if (candidateCost < lowestCost)
1291	{
1292	//Debug << "choose ray plane 2: " << candidateCost << endl;
1293	bestPlane = plane;
1294
1295	lowestCost = candidateCost;
1296	}
1297	}
1298
1299	#ifdef _DEBUG
1300	Debug << "plane lowest cost: " << lowestCost << endl;
1301	#endif
1302	return bestPlane;
1303	}
1304
1305	int BspTree::GetNextCandidateIdx(int currentIdx, PolygonContainer &polys)
1306	{
1307	const int candidateIdx = Random(currentIdx --);
1308
1309	// swap candidates to avoid testing same plane 2 times
1310	std::swap(polys[currentIdx], polys[candidateIdx]);
1311
1312	return currentIdx;
1313	//return Random((int)polys.size());
1314	}
1315
1316	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1317	const PolygonContainer &polys) const
1318	{
1319	float val = 0;
1320
1321	float sumBalancedPolys = 0;
1322	float sumSplits = 0;
1323	float sumPolyArea = 0;
1324	float sumBalancedViewCells = 0;
1325	float sumBlockedRays = 0;
1326	float totalBlockedRays = 0;
1327	//float totalArea = 0;
1328	int totalViewCells = 0;
1329
1330	// need three unique ids for each type of view cell
1331	// for balanced view cells criterium
1332	ViewCell::NewMail();
1333	const int backId = ViewCell::sMailId;
1334	ViewCell::NewMail();
1335	const int frontId = ViewCell::sMailId;
1336	ViewCell::NewMail();
1337	const int frontAndBackId = ViewCell::sMailId;
1338
1339	PolygonContainer::const_iterator it, it_end = polys.end();
1340
1341	for (it = polys.begin(); it != it_end; ++ it)
1342	{
1343	const int classification = (*it)->ClassifyPlane(candidatePlane);
1344
1345	if (mSplitPlaneStrategy & BALANCED_POLYS)
1346	sumBalancedPolys += sBalancedPolysTable[classification];
1347
1348	if (mSplitPlaneStrategy & LEAST_SPLITS)
1349	sumSplits += sLeastPolySplitsTable[classification];
1350
1351	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1352	{
1353	if (classification == Polygon3::COINCIDENT)
1354	sumPolyArea += (*it)->GetArea();
1355	//totalArea += area;
1356	}
1357
1358	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1359	{
1360	const float blockedRays = (float)(*it)->mPiercingRays.size();
1361
1362	if (classification == Polygon3::COINCIDENT)
1363	sumBlockedRays += blockedRays;
1364
1365	totalBlockedRays += blockedRays;
1366	}
1367
1368	// assign view cells to back or front according to classificaion
1369	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1370	{
1371	MeshInstance viewCell = (it)->mParent;
1372
1373	// assure that we only count a view cell
1374	// once for the front and once for the back side of the plane
1375	if (classification == Polygon3::FRONT_SIDE)
1376	{
1377	if ((viewCell->mMailbox != frontId) &&
1378	(viewCell->mMailbox != frontAndBackId))
1379	{
1380	sumBalancedViewCells += 1.0;
1381
1382	if (viewCell->mMailbox != backId)
1383	viewCell->mMailbox = frontId;
1384	else
1385	viewCell->mMailbox = frontAndBackId;
1386
1387	++ totalViewCells;
1388	}
1389	}
1390	else if (classification == Polygon3::BACK_SIDE)
1391	{
1392	if ((viewCell->mMailbox != backId) &&
1393	(viewCell->mMailbox != frontAndBackId))
1394	{
1395	sumBalancedViewCells -= 1.0;
1396
1397	if (viewCell->mMailbox != frontId)
1398	viewCell->mMailbox = backId;
1399	else
1400	viewCell->mMailbox = frontAndBackId;
1401
1402	++ totalViewCells;
1403	}
1404	}
1405	}
1406	}
1407
1408	const float polysSize = (float)polys.size() + Limits::Small;
1409
1410	// all values should be approx. between 0 and 1 so they can be combined
1411	// and scaled with the factors according to their importance
1412	if (mSplitPlaneStrategy & BALANCED_POLYS)
1413	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1414
1415	if (mSplitPlaneStrategy & LEAST_SPLITS)
1416	val += mLeastSplitsFactor * sumSplits / polysSize;
1417
1418	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1419	// HACK: polys.size should be total area so scaling is between 0 and 1
1420	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1421
1422	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1423	if (totalBlockedRays != 0)
1424	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1425
1426	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1427	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1428	((float)totalViewCells + Limits::Small);
1429
1430	return val;
1431	}
1432
1433	bool BspTree::BoundRay(const Ray &ray, float &minT, float &maxT) const
1434	{
1435	maxT = 1e6;
1436	minT = 0;
1437
1438	// test with tree bounding box
1439	if (!mBox.GetMinMaxT(ray, &minT, &maxT))
1440	return false;
1441
1442	if (minT < 0) // start ray from origin
1443	minT = 0;
1444
1445	// bound ray or line segment
1446	if ((ray.GetType() == Ray::LOCAL_RAY) &&
1447	!ray.intersections.empty() &&
1448	(ray.intersections[0].mT <= maxT))
1449	{
1450	maxT = ray.intersections[0].mT;
1451	}
1452
1453	return true;
1454	}
1455
1456	inline void BspTree::GenerateUniqueIdsForPvs()
1457	{
1458	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1459	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1460	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1461	}
1462
1463	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1464	const BoundedRayContainer &rays,
1465	const int pvs,
1466	const float area,
1467	const BspNodeGeometry &cell) const
1468	{
1469	float val = 0;
1470
1471	float sumBalancedRays = 0;
1472	float sumRaySplits = 0;
1473
1474	int backId = 0;
1475	int frontId = 0;
1476	int frontAndBackId = 0;
1477
1478	int frontPvs = 0;
1479	int backPvs = 0;
1480
1481	// probability that view point lies in child
1482	float pOverall = 0;
1483	float pFront = 0;
1484	float pBack = 0;
1485
1486	if (mSplitPlaneStrategy & PVS)
1487	{
1488	// create unique ids for pvs heuristics
1489	GenerateUniqueIdsForPvs();
1490
1491	if (mPvsUseArea) // use front and back cell areas to approximate volume
1492	{
1493	// construct child geometry with regard to the candidate split plane
1494	BspNodeGeometry frontCell;
1495	BspNodeGeometry backCell;
1496
1497	cell.SplitGeometry(frontCell, backCell, *this, candidatePlane);
1498
1499	pFront = frontCell.GetArea();
1500	pBack = backCell.GetArea();
1501
1502	pOverall = area;
1503	}
1504	}
1505
1506	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
1507
1508	for (rit = rays.begin(); rit != rays.end(); ++ rit)
1509	{
1510	Ray ray = (rit)->mRay;
1511	const float minT = (*rit)->mMinT;
1512	const float maxT = (*rit)->mMaxT;
1513
1514	Vector3 entP, extP;
1515
1516	const int cf =
1517	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1518
1519	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1520	{
1521	sumBalancedRays += sBalancedRaysTable[cf];
1522	}
1523
1524	if (mSplitPlaneStrategy & BALANCED_RAYS)
1525	{
1526	sumRaySplits += sLeastRaySplitsTable[cf];
1527	}
1528
1529	if (mSplitPlaneStrategy & PVS)
1530	{
1531	// in case the ray intersects an object
1532	// assure that we only count the object
1533	// once for the front and once for the back side of the plane
1534
1535	// add the termination object
1536	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1537
1538	// add the source object
1539	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1540
1541	if (!mPvsUseArea) // use front and back cell areas to approximate volume
1542	{
1543	float len = Distance(entP, extP);
1544	pOverall += len;
1545
1546	// use length of rays to approximate volume
1547	switch (cf)
1548	{
1549	case Ray::COINCIDENT:
1550	pBack += len;
1551	pFront += len;
1552	break;
1553	case Ray::BACK:
1554	pBack += len;
1555	break;
1556	case Ray::FRONT:
1557	pFront += len;
1558	break;
1559	case Ray::FRONT_BACK:
1560	{
1561	// find intersection of ray segment with plane
1562	const Vector3 extp = ray->Extrap(maxT);
1563	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1564
1565	const float newT = t * maxT;
1566	float newLen = Distance(ray->Extrap(newT), extp);
1567
1568	pFront += len - newLen;
1569	pBack += newLen;
1570	}
1571	break;
1572	case Ray::BACK_FRONT:
1573	{
1574	// find intersection of ray segment with plane
1575	const Vector3 extp = ray->Extrap(maxT);
1576	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1577
1578	const float newT = t * maxT;
1579	float newLen = Distance(ray->Extrap(newT), extp);
1580
1581	pFront += len;
1582	pBack += len - newLen;
1583	}
1584	break;
1585	default:
1586	Debug << "Should not come here 2" << endl;
1587	break;
1588	}
1589	}
1590	}
1591	}
1592
1593	const float raysSize = (float)rays.size() + Limits::Small;
1594	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1595	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1596
1597	if (mSplitPlaneStrategy & BALANCED_RAYS)
1598	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1599
1600	float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1601	if ((mSplitPlaneStrategy & PVS) && area && pvs)
1602	{
1603	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1604
1605	// give penalty to unbalanced split
1606	if (1)
1607	if (((pFront * 0.2 + Limits::Small) > pBack) \|\| (pFront < (pBack * 0.2 + Limits::Small)))
1608	val += 0.5;
1609	}
1610
1611	#ifdef _DEBUG
1612	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1613	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1614	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1615	#endif
1616	return val;
1617	}
1618
1619	void BspTree::AddObjToPvs(Intersectable *obj,
1620	const int cf,
1621	int &frontPvs,
1622	int &backPvs) const
1623	{
1624	if (!obj)
1625	return;
1626	// TODO: does this really belong to no pvs?
1627	//if (cf == Ray::COINCIDENT) return;
1628
1629	// object belongs to both PVS
1630	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1631	(cf == Ray::BACK_FRONT) \|\|
1632	(cf == Ray::COINCIDENT);
1633
1634	if ((cf == Ray::FRONT) \|\| bothSides)
1635	{
1636	if ((obj->mMailbox != sFrontId) &&
1637	(obj->mMailbox != sFrontAndBackId))
1638	{
1639	++ frontPvs;
1640
1641	if (obj->mMailbox == sBackId)
1642	obj->mMailbox = sFrontAndBackId;
1643	else
1644	obj->mMailbox = sFrontId;
1645	}
1646	}
1647
1648	if ((cf == Ray::BACK) \|\| bothSides)
1649	{
1650	if ((obj->mMailbox != sBackId) &&
1651	(obj->mMailbox != sFrontAndBackId))
1652	{
1653	++ backPvs;
1654
1655	if (obj->mMailbox == sFrontId)
1656	obj->mMailbox = sFrontAndBackId;
1657	else
1658	obj->mMailbox = sBackId;
1659	}
1660	}
1661	}
1662
1663	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1664	BspTraversalData &data) const
1665	{
1666	float val = 0;
1667
1668	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1669	{
1670	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1671	// we put a penalty on the dot product between the "tiny" vertical axis
1672	// and the split plane axis
1673	val += mVerticalSplitsFactor *
1674	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1675	}
1676
1677	// the following criteria loop over all polygons to find the cost value
1678	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1679	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1680	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1681	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1682	(mSplitPlaneStrategy & BLOCKED_RAYS))
1683	{
1684	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1685	}
1686
1687	// the following criteria loop over all rays to find the cost value
1688	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1689	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1690	(mSplitPlaneStrategy & PVS))
1691	{
1692	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1693	data.mArea, *data.mGeometry);
1694	}
1695
1696	// return linear combination of the sums
1697	return val;
1698	}
1699
1700	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1701	{
1702	stack<BspNode *> nodeStack;
1703	nodeStack.push(mRoot);
1704
1705	while (!nodeStack.empty())
1706	{
1707	BspNode *node = nodeStack.top();
1708
1709	nodeStack.pop();
1710
1711	if (node->IsLeaf())
1712	{
1713	BspLeaf leaf = (BspLeaf )node;
1714	leaves.push_back(leaf);
1715	}
1716	else
1717	{
1718	BspInterior interior = dynamic_cast<BspInterior >(node);
1719
1720	nodeStack.push(interior->GetBack());
1721	nodeStack.push(interior->GetFront());
1722	}
1723	}
1724	}
1725
1726	AxisAlignedBox3 BspTree::GetBoundingBox() const
1727	{
1728	return mBox;
1729	}
1730
1731	BspNode *BspTree::GetRoot() const
1732	{
1733	return mRoot;
1734	}
1735
1736	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1737	{
1738	// the node became a leaf -> evaluate stats for leafs
1739	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1740
1741	// store maximal and minimal depth
1742	if (data.mDepth > mStat.maxDepth)
1743	mStat.maxDepth = data.mDepth;
1744
1745	if (data.mDepth < mStat.minDepth)
1746	mStat.minDepth = data.mDepth;
1747
1748	// accumulate depth to compute average depth
1749	mStat.accumDepth += data.mDepth;
1750
1751
1752	if (data.mDepth >= mTermMaxDepth)
1753	++ mStat.maxDepthNodes;
1754
1755	if (data.mPvs < mTermMinPvs)
1756	++ mStat.minPvsNodes;
1757
1758	if ((int)data.mRays->size() < mTermMinRays)
1759	++ mStat.minRaysNodes;
1760
1761	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1762	++ mStat.maxRayContribNodes;
1763
1764	if (data.mGeometry->GetArea() <= mTermMinArea)
1765	++ mStat.minAreaNodes;
1766
1767	#ifdef _DEBUG
1768	Debug << "BSP stats: "
1769	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1770	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1771	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1772	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1773	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1774	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1775	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1776	#endif
1777	}
1778
1779	int BspTree::CastRay(Ray &ray)
1780	{
1781	int hits = 0;
1782
1783	stack<BspRayTraversalData> tStack;
1784
1785	float maxt, mint;
1786
1787	if (!BoundRay(ray, mint, maxt))
1788	return 0;
1789
1790	Intersectable::NewMail();
1791
1792	Vector3 entp = ray.Extrap(mint);
1793	Vector3 extp = ray.Extrap(maxt);
1794
1795	BspNode *node = mRoot;
1796	BspNode *farChild = NULL;
1797
1798	while (1)
1799	{
1800	if (!node->IsLeaf())
1801	{
1802	BspInterior in = (BspInterior ) node;
1803
1804	Plane3 *splitPlane = in->GetPlane();
1805
1806	int entSide = splitPlane->Side(entp);
1807	int extSide = splitPlane->Side(extp);
1808
1809	Vector3 intersection;
1810
1811	if (entSide < 0)
1812	{
1813	node = in->GetBack();
1814
1815	if(extSide <= 0) // plane does not split ray => no far child
1816	continue;
1817
1818	farChild = in->GetFront(); // plane splits ray
1819
1820	} else if (entSide > 0)
1821	{
1822	node = in->GetFront();
1823
1824	if (extSide >= 0) // plane does not split ray => no far child
1825	continue;
1826
1827	farChild = in->GetBack(); // plane splits ray
1828	}
1829	else // ray and plane are coincident
1830	{
1831	// WHAT TO DO IN THIS CASE ?
1832	//break;
1833	node = in->GetFront();
1834	continue;
1835	}
1836
1837	// push data for far child
1838	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1839
1840	// find intersection of ray segment with plane
1841	float t;
1842	extp = splitPlane->FindIntersection(ray.GetLoc(), extp, &t);
1843	maxt *= t;
1844
1845	} else // reached leaf => intersection with view cell
1846	{
1847	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1848
1849	if (!leaf->mViewCell->Mailed())
1850	{
1851	ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1852	leaf->mViewCell->Mail();
1853	++ hits;
1854	}
1855
1856	//-- fetch the next far child from the stack
1857	if (tStack.empty())
1858	break;
1859
1860	entp = extp;
1861	mint = maxt; // NOTE: need this?
1862
1863	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1864	break;
1865
1866	BspRayTraversalData &s = tStack.top();
1867
1868	node = s.mNode;
1869	extp = s.mExitPoint;
1870	maxt = s.mMaxT;
1871
1872	tStack.pop();
1873	}
1874	}
1875
1876	return hits;
1877	}
1878
1879	bool BspTree::Export(const string filename)
1880	{
1881	Exporter *exporter = Exporter::GetExporter(filename);
1882
1883	if (exporter)
1884	{
1885	exporter->ExportBspTree(*this);
1886	return true;
1887	}
1888
1889	return false;
1890	}
1891
1892	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
1893	{
1894	stack<BspNode *> nodeStack;
1895	nodeStack.push(mRoot);
1896
1897	ViewCell::NewMail();
1898
1899	while (!nodeStack.empty())
1900	{
1901	BspNode *node = nodeStack.top();
1902	nodeStack.pop();
1903
1904	if (node->IsLeaf())
1905	{
1906	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1907
1908	if (!viewCell->Mailed())
1909	{
1910	viewCell->Mail();
1911	viewCells.push_back(viewCell);
1912	}
1913	}
1914	else
1915	{
1916	BspInterior interior = dynamic_cast<BspInterior >(node);
1917
1918	nodeStack.push(interior->mFront);
1919	nodeStack.push(interior->mBack);
1920	}
1921	}
1922	}
1923
1924	void BspTree::EvaluateViewCellsStats(BspViewCellsStatistics &stat) const
1925	{
1926	stat.Reset();
1927
1928	stack<BspNode *> nodeStack;
1929	nodeStack.push(mRoot);
1930
1931	ViewCell::NewMail();
1932
1933	// exclude root cell
1934	mRootCell->Mail();
1935
1936	while (!nodeStack.empty())
1937	{
1938	BspNode *node = nodeStack.top();
1939	nodeStack.pop();
1940
1941	if (node->IsLeaf())
1942	{
1943	++ stat.bspLeaves;
1944
1945	BspViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1946
1947	if (!viewCell->Mailed())
1948	{
1949	viewCell->Mail();
1950
1951	++ stat.viewCells;
1952	const int pvsSize = viewCell->GetPvs().GetSize();
1953
1954	stat.pvs += pvsSize;
1955
1956	if (pvsSize < 1)
1957	++ stat.emptyPvs;
1958
1959	if (pvsSize > stat.maxPvs)
1960	stat.maxPvs = pvsSize;
1961
1962	if (pvsSize < stat.minPvs)
1963	stat.minPvs = pvsSize;
1964
1965	if ((int)viewCell->mBspLeaves.size() > stat.maxBspLeaves)
1966	stat.maxBspLeaves = (int)viewCell->mBspLeaves.size();
1967	}
1968	}
1969	else
1970	{
1971	BspInterior interior = dynamic_cast<BspInterior >(node);
1972
1973	nodeStack.push(interior->mFront);
1974	nodeStack.push(interior->mBack);
1975	}
1976	}
1977	}
1978
1979	bool BspTree::MergeViewCells(BspLeaf front, BspLeaf back) const
1980	{
1981	BspViewCell *viewCell =
1982	dynamic_cast<BspViewCell >(ViewCell::Merge(front->mViewCell, *back->mViewCell));
1983
1984	if (!viewCell)
1985	return false;
1986
1987	// change view cells of all leaves associated with the
1988	// previous view cells
1989
1990	BspViewCell *fVc = front->mViewCell;
1991	BspViewCell *bVc = back->mViewCell;
1992
1993	vector<BspLeaf *> fLeaves = fVc->mBspLeaves;
1994	vector<BspLeaf *> bLeaves = bVc->mBspLeaves;
1995
1996	vector<BspLeaf *>::const_iterator it;
1997
1998	for (it = fLeaves.begin(); it != fLeaves.end(); ++ it)
1999	{
2000	(*it)->SetViewCell(viewCell);
2001	viewCell->mBspLeaves.push_back(*it);
2002	}
2003	for (it = bLeaves.begin(); it != bLeaves.end(); ++ it)
2004	{
2005	(*it)->SetViewCell(viewCell);
2006	viewCell->mBspLeaves.push_back(*it);
2007	}
2008
2009	DEL_PTR(fVc);
2010	DEL_PTR(bVc);
2011
2012	return true;
2013	}
2014
2015	bool BspTree::ShouldMerge(BspLeaf front, BspLeaf back) const
2016	{
2017	ViewCell *fvc = front->mViewCell;
2018	ViewCell *bvc = back->mViewCell;
2019
2020	if ((fvc == mRootCell) \|\| (bvc == mRootCell) \|\| (fvc == bvc))
2021	return false;
2022
2023	int fdiff = fvc->GetPvs().Diff(bvc->GetPvs());
2024
2025	if (fvc->GetPvs().GetSize() + fdiff < mMaxPvs)
2026	{
2027	if ((fvc->GetPvs().GetSize() < mMinPvs) \|\|
2028	(bvc->GetPvs().GetSize() < mMinPvs) \|\|
2029	((fdiff < mMinPvsDif) && (bvc->GetPvs().Diff(fvc->GetPvs()) < mMinPvsDif)))
2030	{
2031	return true;
2032	}
2033	}
2034
2035	return false;
2036	}
2037
2038	void BspTree::SetGenerateViewCells(int generateViewCells)
2039	{
2040	mGenerateViewCells = generateViewCells;
2041	}
2042
2043	BspTreeStatistics &BspTree::GetStat()
2044	{
2045	return mStat;
2046	}
2047
2048	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2049	{
2050	float len = 0;
2051
2052	BoundedRayContainer::const_iterator it, it_end = rays.end();
2053
2054	for (it = rays.begin(); it != it_end; ++ it)
2055	{
2056	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2057	(it)->mRay->Extrap((it)->mMaxT));
2058	}
2059
2060	return len;
2061	}
2062
2063	int BspTree::SplitRays(const Plane3 &plane,
2064	BoundedRayContainer &rays,
2065	BoundedRayContainer &frontRays,
2066	BoundedRayContainer &backRays)
2067	{
2068	int splits = 0;
2069
2070	while (!rays.empty())
2071	{
2072	BoundedRay *bRay = rays.back();
2073	Ray *ray = bRay->mRay;
2074	float minT = bRay->mMinT;
2075	float maxT = bRay->mMaxT;
2076
2077	rays.pop_back();
2078
2079	Vector3 entP, extP;
2080
2081	const int cf =
2082	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2083
2084	// set id to ray classification
2085	ray->SetId(cf);
2086
2087	switch (cf)
2088	{
2089	case Ray::COINCIDENT: // TODO: should really discard ray?
2090	frontRays.push_back(bRay);
2091	//DEL_PTR(bRay);
2092	break;
2093	case Ray::BACK:
2094	backRays.push_back(bRay);
2095	break;
2096	case Ray::FRONT:
2097	frontRays.push_back(bRay);
2098	break;
2099	case Ray::FRONT_BACK:
2100	{
2101	// find intersection of ray segment with plane
2102	const float t = plane.FindT(ray->GetLoc(), extP);
2103
2104	const float newT = t * maxT;
2105
2106	frontRays.push_back(new BoundedRay(ray, minT, newT));
2107	backRays.push_back(new BoundedRay(ray, newT, maxT));
2108
2109	DEL_PTR(bRay);
2110	}
2111	break;
2112	case Ray::BACK_FRONT:
2113	{
2114	// find intersection of ray segment with plane
2115	const float t = plane.FindT(ray->GetLoc(), extP);
2116	const float newT = t * bRay->mMaxT;
2117
2118	backRays.push_back(new BoundedRay(ray, bRay->mMinT, newT));
2119	frontRays.push_back(new BoundedRay(ray, newT, bRay->mMaxT));
2120	DEL_PTR(bRay);
2121
2122	++ splits;
2123	}
2124	break;
2125	default:
2126	Debug << "Should not come here 4" << endl;
2127	break;
2128	}
2129	}
2130
2131	return splits;
2132	}
2133
2134	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2135	{
2136	BspNode *lastNode;
2137	do
2138	{
2139	lastNode = n;
2140
2141	// want to get planes defining geometry of this node => don't take
2142	// split plane of node itself
2143	n = n->GetParent();
2144
2145	if (n)
2146	{
2147	BspInterior interior = dynamic_cast<BspInterior >(n);
2148	Plane3 halfSpace = dynamic_cast<BspInterior >(interior)->GetPlane();
2149
2150	if (interior->mFront != lastNode)
2151	halfSpace.ReverseOrientation();
2152
2153	halfSpaces.push_back(halfSpace);
2154	}
2155	}
2156	while (n);
2157	}
2158
2159	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &cell) const
2160	{
2161	PolygonContainer polys;
2162	ConstructGeometry(n, polys);
2163	cell.mPolys = polys;
2164	}
2165
2166	void BspTree::ConstructGeometry(BspViewCell *vc, PolygonContainer &cell) const
2167	{
2168	vector<BspLeaf *> leaves = vc->mBspLeaves;
2169
2170	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2171
2172	for (it = leaves.begin(); it != it_end; ++ it)
2173	ConstructGeometry(*it, cell);
2174	}
2175
2176
2177	void BspTree::ConstructGeometry(BspNode *n, PolygonContainer &cell) const
2178	{
2179	vector<Plane3> halfSpaces;
2180	ExtractHalfSpaces(n, halfSpaces);
2181
2182	PolygonContainer candidatePolys;
2183
2184	// bounded planes are added to the polygons (reverse polygons
2185	// as they have to be outfacing
2186	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2187	{
2188	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2189
2190	if (p->Valid())
2191	{
2192	candidatePolys.push_back(p->CreateReversePolygon());
2193	DEL_PTR(p);
2194	}
2195	}
2196
2197	// add faces of bounding box (also could be faces of the cell)
2198	for (int i = 0; i < 6; ++ i)
2199	{
2200	VertexContainer vertices;
2201
2202	for (int j = 0; j < 4; ++ j)
2203	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2204
2205	candidatePolys.push_back(new Polygon3(vertices));
2206	}
2207
2208	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2209	{
2210	// polygon is split by all other planes
2211	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2212	{
2213	if (i == j) // polygon and plane are coincident
2214	continue;
2215
2216	VertexContainer splitPts;
2217	Polygon3 frontPoly, backPoly;
2218
2219	const int cf = candidatePolys[i]->ClassifyPlane(halfSpaces[j]);
2220
2221	switch (cf)
2222	{
2223	case Polygon3::SPLIT:
2224	frontPoly = new Polygon3();
2225	backPoly = new Polygon3();
2226
2227	candidatePolys[i]->Split(halfSpaces[j],
2228	*frontPoly,
2229	*backPoly);
2230
2231	DEL_PTR(candidatePolys[i]);
2232
2233	if (frontPoly->Valid())
2234	candidatePolys[i] = frontPoly;
2235	else
2236	DEL_PTR(frontPoly);
2237
2238	DEL_PTR(backPoly);
2239	break;
2240	case Polygon3::BACK_SIDE:
2241	DEL_PTR(candidatePolys[i]);
2242	break;
2243	// just take polygon as it is
2244	case Polygon3::FRONT_SIDE:
2245	case Polygon3::COINCIDENT:
2246	default:
2247	break;
2248	}
2249	}
2250
2251	if (candidatePolys[i])
2252	cell.push_back(candidatePolys[i]);
2253	}
2254	}
2255
2256
2257	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2258	const bool onlyUnmailed) const
2259	{
2260	PolygonContainer cell;
2261
2262	ConstructGeometry(n, cell);
2263
2264	stack<BspNode *> nodeStack;
2265	nodeStack.push(mRoot);
2266
2267	// planes needed to verify that we found neighbor leaf.
2268	vector<Plane3> halfSpaces;
2269	ExtractHalfSpaces(n, halfSpaces);
2270
2271	while (!nodeStack.empty())
2272	{
2273	BspNode *node = nodeStack.top();
2274	nodeStack.pop();
2275
2276	if (node->IsLeaf())
2277	{
2278	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2279	{
2280	// test all planes of current node if candidate really
2281	// is neighbour
2282	PolygonContainer neighborCandidate;
2283	ConstructGeometry(node, neighborCandidate);
2284
2285	bool isAdjacent = true;
2286	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2287	{
2288	const int cf =
2289	Polygon3::ClassifyPlane(neighborCandidate, halfSpaces[i]);
2290
2291	if (cf == Polygon3::BACK_SIDE)
2292	isAdjacent = false;
2293	}
2294
2295	if (isAdjacent)
2296	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2297
2298	CLEAR_CONTAINER(neighborCandidate);
2299	}
2300	}
2301	else
2302	{
2303	BspInterior interior = dynamic_cast<BspInterior >(node);
2304
2305	const int cf = Polygon3::ClassifyPlane(cell, interior->mPlane);
2306
2307	if (cf == Polygon3::FRONT_SIDE)
2308	nodeStack.push(interior->mFront);
2309	else
2310	if (cf == Polygon3::BACK_SIDE)
2311	nodeStack.push(interior->mBack);
2312	else
2313	{
2314	// random decision
2315	nodeStack.push(interior->mBack);
2316	nodeStack.push(interior->mFront);
2317	}
2318	}
2319	}
2320
2321	CLEAR_CONTAINER(cell);
2322	return (int)neighbors.size();
2323	}
2324
2325	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2326	{
2327	stack<BspNode *> nodeStack;
2328	nodeStack.push(mRoot);
2329
2330	int mask = rand();
2331
2332	while (!nodeStack.empty())
2333	{
2334	BspNode *node = nodeStack.top();
2335	nodeStack.pop();
2336
2337	if (node->IsLeaf())
2338	{
2339	return dynamic_cast<BspLeaf *>(node);
2340	}
2341	else
2342	{
2343	BspInterior interior = dynamic_cast<BspInterior >(node);
2344
2345	BspNode *next;
2346
2347	PolygonContainer cell;
2348
2349	// todo: not very efficient: constructs full cell everytime
2350	ConstructGeometry(interior, cell);
2351
2352	const int cf = Polygon3::ClassifyPlane(cell, halfspace);
2353
2354	if (cf == Polygon3::BACK_SIDE)
2355	next = interior->mFront;
2356	else
2357	if (cf == Polygon3::FRONT_SIDE)
2358	next = interior->mFront;
2359	else
2360	{
2361	// random decision
2362	if (mask & 1)
2363	next = interior->mBack;
2364	else
2365	next = interior->mFront;
2366	mask = mask >> 1;
2367	}
2368
2369	nodeStack.push(next);
2370	}
2371	}
2372
2373	return NULL;
2374	}
2375
2376	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2377	{
2378	stack<BspNode *> nodeStack;
2379
2380	nodeStack.push(mRoot);
2381
2382	int mask = rand();
2383
2384	while (!nodeStack.empty())
2385	{
2386	BspNode *node = nodeStack.top();
2387	nodeStack.pop();
2388
2389	if (node->IsLeaf())
2390	{
2391	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2392	return dynamic_cast<BspLeaf *>(node);
2393	}
2394	else
2395	{
2396	BspInterior interior = dynamic_cast<BspInterior >(node);
2397
2398	// random decision
2399	if (mask & 1)
2400	nodeStack.push(interior->mBack);
2401	else
2402	nodeStack.push(interior->mFront);
2403
2404	mask = mask >> 1;
2405	}
2406	}
2407
2408	return NULL;
2409	}
2410
2411	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2412	{
2413	int pvsSize = 0;
2414
2415	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2416
2417	Intersectable::NewMail();
2418
2419	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2420	{
2421	Ray ray = (rit)->mRay;
2422
2423	if (!ray->intersections.empty())
2424	{
2425	if (!ray->intersections[0].mObject->Mailed())
2426	{
2427	ray->intersections[0].mObject->Mail();
2428	++ pvsSize;
2429	}
2430	}
2431	if (ray->sourceObject.mObject)
2432	{
2433	if (!ray->sourceObject.mObject->Mailed())
2434	{
2435	ray->sourceObject.mObject->Mail();
2436	++ pvsSize;
2437	}
2438	}
2439	}
2440
2441	return pvsSize;
2442	}
2443
2444	/*************************************************************
2445	* BspNodeGeometry Implementation *
2446	*************************************************************/
2447
2448	BspNodeGeometry::~BspNodeGeometry()
2449	{
2450	CLEAR_CONTAINER(mPolys);
2451	}
2452
2453	float BspNodeGeometry::GetArea() const
2454	{
2455	return Polygon3::GetArea(mPolys);
2456	}
2457
2458	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2459	BspNodeGeometry &back,
2460	const BspTree &tree,
2461	const Plane3 &splitPlane) const
2462	{
2463	// get cross section of new polygon
2464	Polygon3 *planePoly = tree.GetBoundingBox().CrossSection(splitPlane);
2465
2466	planePoly = SplitPolygon(planePoly, tree);
2467
2468	//-- plane poly splits all other cell polygons
2469	for (int i = 0; i < (int)mPolys.size(); ++ i)
2470	{
2471	const int cf = mPolys[i]->ClassifyPlane(splitPlane, 0.00001f);
2472
2473	// split new polygon with all previous planes
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, frontPoly, backPoly);
2484
2485	DEL_PTR(poly);
2486
2487	if (frontPoly->Valid())
2488	front.mPolys.push_back(frontPoly);
2489	if (backPoly->Valid())
2490	back.mPolys.push_back(backPoly);
2491	}
2492
2493	break;
2494	case Polygon3::BACK_SIDE:
2495	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2496	break;
2497	case Polygon3::FRONT_SIDE:
2498	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2499	break;
2500	case Polygon3::COINCIDENT:
2501	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2502	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2503	break;
2504	default:
2505	break;
2506	}
2507	}
2508
2509	//-- finally add the new polygon to the child cells
2510	if (planePoly)
2511	{
2512	// add polygon with normal pointing into positive half space to back cell
2513	back.mPolys.push_back(planePoly);
2514	// add polygon with reverse orientation to front cell
2515	front.mPolys.push_back(planePoly->CreateReversePolygon());
2516	}
2517
2518	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2519	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2520	}
2521
2522	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2523	const BspTree &tree) const
2524	{
2525	// polygon is split by all other planes
2526	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2527	{
2528	Plane3 plane = mPolys[i]->GetSupportingPlane();
2529
2530	const int cf =
2531	planePoly->ClassifyPlane(plane, 0.00001f);
2532
2533	// split new polygon with all previous planes
2534	switch (cf)
2535	{
2536	case Polygon3::SPLIT:
2537	{
2538	Polygon3 *frontPoly = new Polygon3();
2539	Polygon3 *backPoly = new Polygon3();
2540
2541	planePoly->Split(plane, frontPoly, backPoly);
2542	DEL_PTR(planePoly);
2543
2544	if (backPoly->Valid())
2545	planePoly = backPoly;
2546	else
2547	DEL_PTR(backPoly);
2548	}
2549	break;
2550	case Polygon3::FRONT_SIDE:
2551	DEL_PTR(planePoly);
2552	break;
2553	// polygon is taken as it is
2554	case Polygon3::BACK_SIDE:
2555	case Polygon3::COINCIDENT:
2556	default:
2557	break;
2558	}
2559	}
2560
2561	return planePoly;
2562	}
2563
2564	void BspViewCellsStatistics::Print(ostream &app) const
2565	{
2566	app << "===== BspViewCells statistics ===============\n";
2567
2568	app << setprecision(4);
2569
2570	//app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
2571
2572	app << "#N_OVERALLPVS ( objects in PVS )\n" << pvs << endl;
2573
2574	app << "#N_PMAXPVS ( largest PVS )\n" << maxPvs << endl;
2575
2576	app << "#N_PMINPVS ( smallest PVS )\n" << minPvs << endl;
2577
2578	app << "#N_PAVGPVS ( average PVS )\n" << AvgPvs() << endl;
2579
2580	app << "#N_PEMPTYPVS ( view cells with PVS smaller 2 )\n" << emptyPvs << endl;
2581
2582	app << "#N_VIEWCELLS ( number of view cells)\n" << viewCells << endl;
2583
2584	app << "#N_AVGBSPLEAVES (average number of BSP leaves per view cell )\n" << AvgBspLeaves() << endl;
2585
2586	app << "#N_MAXBSPLEAVES ( maximal number of BSP leaves per view cell )\n" << maxBspLeaves << endl;
2587
2588	app << "===== END OF BspViewCells statistics ==========\n";
2589	}

Note: See TracBrowser for help on using the repository browser.

Download in other formats: