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source: trunk/VUT/GtpVisibilityPreprocessor/src/VssPreprocessor.cpp @ 403

Revision 403, 8.2 KB checked in by bittner, 19 years ago (diff)
vvs preprocessor update

Line
1	#include "SceneGraph.h"
2	#include "KdTree.h"
3	#include "VssPreprocessor.h"
4	#include "X3dExporter.h"
5	#include "Environment.h"
6	#include "MutualVisibility.h"
7	#include "Polygon3.h"
8	#include "ViewCell.h"
9	#include "VssRay.h"
10	#include "VssTree.h"
11
12	VssPreprocessor::VssPreprocessor():
13	mPass(0),
14	mVssRays()
15	{
16	// this should increase coherence of the samples
17	environment->GetIntValue("VssPreprocessor.samplesPerPass", mSamplesPerPass);
18	environment->GetIntValue("VssPreprocessor.initialSamples", mInitialSamples);
19	environment->GetIntValue("VssPreprocessor.vssSamples", mVssSamples);
20	environment->GetBoolValue("VssPreprocessor.useImportanceSampling", mUseImportanceSampling);
21
22	mStats.open("stats.log");
23	}
24
25	VssPreprocessor::~VssPreprocessor()
26	{
27	CLEAR_CONTAINER(mVssRays);
28	}
29
30	void
31	VssPreprocessor::SetupRay(Ray &ray,
32	const Vector3 &point,
33	const Vector3 &direction
34	)
35	{
36	ray.intersections.clear();
37	// do not store anything else then intersections at the ray
38	ray.Init(point, direction, Ray::LOCAL_RAY);
39	}
40
41	int
42	VssPreprocessor::CastRay(
43	Vector3 &viewPoint,
44	Vector3 &direction,
45	VssRayContainer &vssRays
46	)
47	{
48	int hits = 0;
49	static Ray ray;
50	AxisAlignedBox3 box = mKdTree->GetBox();
51
52	SetupRay(ray, viewPoint, direction);
53	// cast ray to KD tree to find intersection with other objects
54	Intersectable objectA, objectB;
55	Vector3 pointA, pointB;
56	float bsize = Magnitude(box.Size());
57	if (mKdTree->CastRay(ray)) {
58	objectA = ray.intersections[0].mObject;
59	pointA = ray.Extrap(ray.intersections[0].mT);
60	} else {
61	objectA = NULL;
62	// compute intersection with the scene bounding box
63	float tmin, tmax;
64	box.ComputeMinMaxT(ray, &tmin, &tmax);
65	if (tmax > bsize) {
66	// cerr<<"Warning: tmax > box size tmax="<<tmax<<" tmin="<<tmin<<" size="<<bsize<<endl;
67	// cerr<<"ray"<<ray<<endl;
68	}
69	pointA = ray.Extrap(tmax);
70
71	}
72
73	bool detectEmptyViewSpace = true;
74
75	if (detectEmptyViewSpace) {
76	SetupRay(ray, pointA, -direction);
77	} else
78	SetupRay(ray, viewPoint, -direction);
79
80
81	if (mKdTree->CastRay(ray)) {
82
83	objectB = ray.intersections[0].mObject;
84	pointB = ray.Extrap(ray.intersections[0].mT);
85
86	} else {
87	objectB = NULL;
88	float tmin, tmax;
89	box.ComputeMinMaxT(ray, &tmin, &tmax);
90	if (tmax > bsize) {
91	// cerr<<"Warning: tmax > box size tmax="<<tmax<<" tmin="<<tmin<<" size="<<bsize<<endl;
92	// cerr<<"ray"<<ray<<endl;
93	}
94
95	pointB = ray.Extrap(tmax);
96	}
97
98	VssRay *vssRay = NULL;
99
100	bool validSample = true;
101	if (detectEmptyViewSpace) {
102	if (Distance(pointA, pointB) <
103	Distance(viewPoint, pointA) + Distance(viewPoint, pointB) - Limits::Small) {
104	validSample = false;
105	}
106	}
107
108	if (validSample) {
109	if (objectA) {
110	vssRay = new VssRay(pointB,
111	pointA,
112	objectB,
113	objectA);
114	vssRays.push_back(vssRay);
115	hits ++;
116	}
117
118	if (objectB) {
119	vssRay = new VssRay(pointA,
120	pointB,
121	objectA,
122	objectB);
123	vssRays.push_back(vssRay);
124	hits ++;
125	}
126	}
127
128	return hits;
129	}
130
131
132	Vector3
133	VssPreprocessor::GetViewpoint(AxisAlignedBox3 *viewSpaceBox)
134	{
135	AxisAlignedBox3 box;
136
137	if (viewSpaceBox)
138	box =*viewSpaceBox;
139	else
140	box = mKdTree->GetBox();
141
142	// shrink the box in the y direction
143	return box.GetRandomPoint();
144	}
145
146	Vector3
147	VssPreprocessor::GetDirection(const Vector3 &viewpoint)
148	{
149	int i = RandomValue(0, mObjects.size()-1);
150	Intersectable *object = mObjects[i];
151	Vector3 point, normal;
152	object->GetRandomSurfacePoint(point, normal);
153	return point - viewpoint;
154	}
155
156	int
157	VssPreprocessor::RandomizedImportanceSampling(VssTree *vssTree,
158	const int desiredSamples)
159	{
160	float minRayContribution;
161	float maxRayContribution;
162	float avgRayContribution;
163
164	vssTree->GetRayContributionStatistics(minRayContribution,
165	maxRayContribution,
166	avgRayContribution);
167
168	cout<<
169	"#MIN_RAY_CONTRIB\n"<<minRayContribution<<endl<<
170	"#MAX_RAY_CONTRIB\n"<<maxRayContribution<<endl<<
171	"#AVG_RAY_CONTRIB\n"<<avgRayContribution<<endl;
172
173	float p = desiredSamples/(float)(avgRayContribution*vssTree->stat.Leaves());
174	SimpleRayContainer rays;
175	int num = vssTree->GenerateRays(p, rays);
176	cout<<"Generated "<<num<<" rays."<<endl;
177
178	VssRayContainer vssRays;
179
180	for (int i=0; i < rays.size(); i++)
181	CastRay(rays[i].mOrigin, rays[i].mDirection, vssRays);
182
183	vssTree->AddRays(vssRays);
184	return num;
185	}
186
187
188	bool
189	VssPreprocessor::ComputeVisibility()
190	{
191
192	mSceneGraph->CollectObjects(&mObjects);
193
194	long startTime = GetTime();
195
196	int totalSamples = 0;
197
198	AxisAlignedBox3 *viewSpaceBox = NULL;
199
200	AxisAlignedBox3 box = mKdTree->GetBox();
201
202
203	if (1)
204	box.Enlarge(box.Size()*-Vector3(0.45, 0.45, 0.45));
205	else {
206	// sample city like heights
207	box.SetMin(1, box.Min(1) + box.Size(1)*0.1);
208	box.SetMax(1, box.Min(1) + box.Size(1)*0.2);
209	}
210
211	bool useViewSpaceBox = false;
212	if (useViewSpaceBox)
213	viewSpaceBox = &box;
214
215	VssTree *vssTree = NULL;
216
217	while (totalSamples < mInitialSamples) {
218	int passContributingSamples = 0;
219	int passSampleContributions = 0;
220	int passSamples = 0;
221	int index = 0;
222
223	int sampleContributions;
224
225
226	for (int k=0; k < mSamplesPerPass; k++) {
227
228	Vector3 viewpoint = GetViewpoint(viewSpaceBox);
229	Vector3 direction = GetDirection(viewpoint);
230
231	sampleContributions = CastRay(viewpoint, direction, mVssRays);
232
233
234	//-- CORR matt: put block inside loop
235	if (sampleContributions) {
236	passContributingSamples ++;
237	passSampleContributions += sampleContributions;
238	}
239	passSamples++;
240	totalSamples++;
241	}
242
243	mPass++;
244
245	int pvsSize = 0;
246	float avgRayContrib = (passContributingSamples > 0) ?
247	passSampleContributions/(float)passContributingSamples : 0;
248
249	cout << "#Pass " << mPass << " : t = " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
250	cout << "#TotalSamples=" << totalSamples/1000
251	<< "k #SampleContributions=" << passSampleContributions << " ("
252	<< 100*passContributingSamples/(float)passSamples<<"%)" << " avgPVS="
253	<< pvsSize/(float)mObjects.size() << endl
254	<< "avg ray contrib=" << avgRayContrib << endl;
255
256	mStats <<
257	"#Pass\n" <<mPass<<endl<<
258	"#Time\n" << TimeDiff(startTime, GetTime())*1e-3 << endl<<
259	"#TotalSamples\n" << totalSamples<< endl<<
260	"#SampleContributions\n" << passSampleContributions << endl <<
261	"#PContributingSamples\n"<<100*passContributingSamples/(float)passSamples<<endl <<
262	"#AvgPVS\n"<< pvsSize/(float)mObjects.size() << endl <<
263	"#AvgRayContrib\n" << avgRayContrib << endl;
264
265
266
267
268	}
269
270	cout << "#totalPvsSize=" << mKdTree->CollectLeafPvs() << endl;
271	cout << "#totalRayStackSize=" << mVssRays.size() << endl <<flush;
272
273	cout<<"Exporting vss rays..."<<endl<<flush;
274
275	int exportRays = 10000;
276
277	if (exportRays) {
278	float prob = exportRays/(float)mVssRays.size();
279
280	Exporter *exporter = NULL;
281	exporter = Exporter::GetExporter("vss-rays.x3d");
282	exporter->SetWireframe();
283	exporter->ExportKdTree(*mKdTree);
284	if (viewSpaceBox) {
285	exporter->SetForcedMaterial(RgbColor(1,0,0));
286	exporter->ExportBox(*viewSpaceBox);
287	exporter->ResetForcedMaterial();
288	}
289	VssRayContainer rays;
290	for (int i=0; i < mVssRays.size(); i++)
291	if (RandomValue(0,1) < prob)
292	rays.push_back(mVssRays[i]);
293	exporter->ExportRays(rays, RgbColor(1, 0, 0));
294
295	delete exporter;
296	}
297	cout<<"done."<<endl<<flush;
298
299
300
301
302	vssTree = new VssTree;
303
304	vssTree->Construct(mVssRays, viewSpaceBox);
305
306	cout<<"VssTree root PVS size = "<<vssTree->GetRootPvsSize()<<endl;
307
308
309	int samples = 0;
310	while (1) {
311	int num = mSamplesPerPass;
312	if (!mUseImportanceSampling) {
313	VssRayContainer vssRays;
314	for (int j=0; j < num; j++) {
315	Vector3 viewpoint = GetViewpoint(viewSpaceBox);
316	Vector3 direction = GetDirection(viewpoint);
317	CastRay(viewpoint, direction, vssRays);
318	}
319	vssTree->AddRays(vssRays);
320	} else {
321	num = RandomizedImportanceSampling(vssTree, num);
322	}
323	samples+=num;
324	float pvs = vssTree->GetAvgPvsSize();
325	cout<<samples<<" avgPVS ="<<pvs<<endl;
326	if (samples >= mVssSamples)
327	break;
328	}
329
330	delete vssTree;
331
332	return true;
333	}
334

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