Changeset 2930

Timestamp:

09/11/08 14:52:51 (16 years ago)

Author:

mattausch

Message:

worked on ssao sampling

Location:

GTP/trunk/App/Demos/Vis/FriendlyCulling/src

Files:

• DeferredRenderer.cpp (modified) (2 diffs)
• DeferredRenderer.h (modified) (1 diff)
• SampleGenerator.cpp (modified) (11 diffs)
• SampleGenerator.h (modified) (3 diffs)
• chcdemo.cpp (modified) (2 diffs)
• shaderenv.h (modified) (1 diff)

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/DeferredRenderer.cpp

@@ -138 +138 @@
         switch (sampling)
         {
-        case DeferredRenderer::POISSON:
+        case DeferredRenderer::SAMPLING_POISSON:
                 {
-                        PoissonDiscSampleGenerator poisson(NUM_SAMPLES, 1.0f);
+                        PoissonDiscSampleGenerator2 poisson(NUM_SAMPLES, 1.0f);
                         poisson.Generate((float *)samples2);
                 }
                 break;
-        case DeferredRenderer::GAUSS:
+        case DeferredRenderer::SAMPLING_QUADRATIC:
                 {
-                        //PoissonDiscSampleGenerator poisson(NUM_SAMPLES, 1.0f);
-                        //poisson.Generate((float *)samples2);
-
-                        PseudoRandomGenerator pseudo(NUM_SAMPLES, 1.0f);
-                        pseudo.Generate((float *)samples2);
+                        QuadraticDiscSampleGenerator2 g(NUM_SAMPLES, 1.0f);
+                        g.Generate((float *)samples2);
                 }
                 break;
-        default:
-                cout << "should not come here" << endl;
-                break;
+        default: // SAMPLING_DEFAULT
+
+                RandomSampleGenerator2 g(NUM_SAMPLES, 1.0f);
+                g.Generate((float *)samples2);
         }
 #endif
@@ -225 +223 @@
 mUseTemporalCoherence(true),
 mRegenerateSamples(true),
-mSamplingMethod(POISSON),
+mSamplingMethod(SAMPLING_POISSON),
 mShadingMethod(DEFAULT),
 mFboIndex(0)

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/DeferredRenderer.h

@@ -53 +53 @@
         void SetUseTemporalCoherence(bool temporal);
 
-        enum SAMPLING_METHOD {POISSON, GAUSS};
+        enum SAMPLING_METHOD {SAMPLING_POISSON, SAMPLING_QUADRATIC, SAMPLING_DEFAULT};
         enum SHADING_METHOD {DEFAULT, SSAO, GI};
 

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/SampleGenerator.cpp

@@ -6 +6 @@
 using namespace CHCDemoEngine;
 
-HaltonSequence SphericalSampleGenerator::sHalton;
-HaltonSequence PoissonDiscSampleGenerator::sHalton;
-HaltonSequence PseudoRandomGenerator::sHalton;
+HaltonSequence SphericalSampleGenerator3::sHalton;
+HaltonSequence PoissonDiscSampleGenerator2::sHalton;
+HaltonSequence RandomSampleGenerator2::sHalton;
+HaltonSequence QuadraticDiscSampleGenerator2::sHalton;
 
 
@@ -16 +17 @@
 
 
-PoissonDiscSampleGenerator::PoissonDiscSampleGenerator(int numSamples, float radius):
+PoissonDiscSampleGenerator2::PoissonDiscSampleGenerator2(int numSamples, float radius):
 SampleGenerator(numSamples, radius)
 {}
 
 
-void PoissonDiscSampleGenerator::Generate(float *samples) const
+void PoissonDiscSampleGenerator2::Generate(float *samples) const
 {
-        // this is a hacky poisson sampling generator which does random dart-throwing
-        // until it is not able to place any dart for a number of tries
-        // in this case, the required min distance is reduced
+        // this is a hacky poisson sampling generator which does random dart-throwing on a disc.
+        // as a savety criterium, the min distance requirement is relaxed if we are not 
+        // able to place any dart for a number of tries
         // the solution is a possion sampling with respect to the adjusted min distance
         // better solutions have been proposed, i.e., using hierarchical sampling
-
         const float maxTries = 1000;
         const float f_reduction = 0.9f;
@@ -36 +36 @@
 
         // generates poisson distribution on disc
-        float minDist = 2.0f * mRadius / sqrt((float)mNumSamples);
+        // start with some threshold. best case: all samples lie on the circumference
+        //const float minDist = 2.0f * mRadius / sqrt((float)mNumSamples);
+        const float eps = 0.2f;
+        const float minDist = 2.0f * mRadius * M_PI * (1.0f - eps) / (float)mNumSamples;
+        float sqrMinDist = minDist * minDist;
 
         //cout << "minDist before= " << minDist << endl;
         Sample2 *s = (Sample2 *)samples;
 
+        int totalTries = 0;
+
+        // check if on disc
         for (int i = 0; i < mNumSamples; ++ i)
         {
-                int tries = 0, totalTries = 0;
+                int tries = 0;
 
                 // repeat until valid sample was found
@@ -51 +58 @@
                         ++ totalTries;
 
-                        r[0] = RandomValue(0, mRadius);
-                        r[1] = RandomValue(0, mRadius);
-                        //halton.GetNext(2, r);
+                        // note: should use halton, but seems somewhat broken
+                        //r[0] = RandomValue(.0f, mRadius);
+                        //r[1] = RandomValue(.0f, mRadius);
+                        sHalton.GetNext(2, r);
 
+                        // scale to -1 .. 1
                         const float rx = r[0] * 2.0f - 1.0f;
                         const float ry = r[1] * 2.0f - 1.0f;
@@ -68 +77 @@
                         {
                                 const float dist = 
-                                        sqrt((s[j].x - rx) * (s[j].x - rx) +
-                                             (s[j].y - ry) * (s[j].y - ry));
+                                        (s[j].x - rx) * (s[j].x - rx) +
+                                        (s[j].y - ry) * (s[j].y - ry);
                         
-                                if (dist < minDist)
+                                if (dist < sqrMinDist)
                                         sampleValid = false;
                         }
@@ -84 +93 @@
                         if (tries > maxTries)
                         {
-                                minDist *= f_reduction;
+                                sqrMinDist *= f_reduction;
                                 tries = 0;
                         }
@@ -90 +99 @@
         }
 
-        //cout << "minDist after= " << minDist << endl;
+        //cout << "minDist after= " << sqrt(sqrMinDist) << " #tries: " << totalTries << endl;
 }
 
 
-PseudoRandomGenerator::PseudoRandomGenerator(int numSamples, float radius):
+RandomSampleGenerator2::RandomSampleGenerator2(int numSamples, float radius):
 SampleGenerator(numSamples, radius)
 {}
 
 
-void PseudoRandomGenerator::Generate(float *samples) const
+void RandomSampleGenerator2::Generate(float *samples) const
 {
         Sample2 *s = (Sample2 *)samples;
@@ -105 +114 @@
         int numSamples = 0;
 
+        float r[2];
+
         while (numSamples < mNumSamples)
         {
-                const float rx = RandomValue(-mRadius, +mRadius);
-                const float ry = RandomValue(-mRadius, +mRadius);
+                //r[0] = RandomValue(-mRadius, mRadius);
+                //r[1] = RandomValue(-mRadius, mRadius);
+                sHalton.GetNext(2, r);
+                
+                const float rx = r[0] * 2.0f - 1.0f;
+                const float ry = r[1] * 2.0f - 1.0f;
 
                 // check if in disk, else exit early
@@ -122 +137 @@
 
 
-SphericalSampleGenerator::SphericalSampleGenerator(int numSamples, float radius):
+SphericalSampleGenerator3::SphericalSampleGenerator3(int numSamples, float radius):
 SampleGenerator(numSamples, radius)
 {}
 
 
-void SphericalSampleGenerator::Generate(float *samples) const
+void SphericalSampleGenerator3::Generate(float *samples) const
 {
         float r[2];
@@ -136 +151 @@
                 r[0] = RandomValue(0, 1);
                 r[1] = RandomValue(0, 1);
+
                 //sHalton.GetNext(2, r);
-                //r[0] = pSamples[i].x; r[1] = pSamples[i].y;
 
                 // create stratified samples over sphere
@@ -147 +162 @@
                 s[i].z = mRadius * cos(theta);
         }
+}
 
-        //delete [] pSamples;
+
+QuadraticDiscSampleGenerator2::QuadraticDiscSampleGenerator2(int numSamples, float radius):
+SampleGenerator(numSamples, radius)
+{}
+
+
+void QuadraticDiscSampleGenerator2::Generate(float *samples) const
+{
+        float r[2];
+        Sample2 *s = (Sample2 *)samples;
+
+        for (int i = 0; i < mNumSamples; ++ i)
+        {
+                //r[0] = samples[i * 2];
+                //r[1] = samples[i * 2 + 1];
+                sHalton.GetNext(2, r);
+
+                // create samples over disc: the sample density
+                // decreases quadratically with the distance to the origin
+                s[i].x = mRadius * r[1] * sin(2.0f * M_PI * r[0]);
+                s[i].y = mRadius * r[1] * cos(2.0f * M_PI * r[0]);
+
+                //s[i].x = mRadius * r[1] * r[1] * sin(2.0f * M_PI * r[0]);
+                //s[i].y = mRadius * r[1] * r[1] * cos(2.0f * M_PI * r[0]);
+        }
 }

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/SampleGenerator.h

@@ -47 +47 @@
 
 
-class PseudoRandomGenerator: public SampleGenerator
+class RandomSampleGenerator2: public SampleGenerator
 {
 public:
         
-        PseudoRandomGenerator(int numSamples, float radius);
+        RandomSampleGenerator2(int numSamples, float radius);
 
         virtual void Generate(float *samples) const;
@@ -65 +65 @@
         according to some d related to the number of samples.
 */
-class PoissonDiscSampleGenerator: public SampleGenerator
+class PoissonDiscSampleGenerator2: public SampleGenerator
 {
 public:
         
-        PoissonDiscSampleGenerator(int numSamples, float radius);
+        PoissonDiscSampleGenerator2(int numSamples, float radius);
 
         virtual void Generate(float *samples) const;
@@ -78 +78 @@
 };
 
-/** This class generates random spherical samples.
+
+/** This class generates random samples on a disc
+        that have the property that their density decreases quadratically
+        with the distance
 */
-class SphericalSampleGenerator: public SampleGenerator
+class QuadraticDiscSampleGenerator2: public SampleGenerator
 {
 public:
         
-        SphericalSampleGenerator(int numSamples, float radius);
+        QuadraticDiscSampleGenerator2(int numSamples, float radius);
+
+        virtual void Generate(float *samples) const;
+
+protected:
+
+        static HaltonSequence sHalton;
+};
+
+
+/** This class generates random spherical samples.
+*/
+class SphericalSampleGenerator3: public SampleGenerator
+{
+public:
+        
+        SphericalSampleGenerator3(int numSamples, float radius);
 
         virtual void Generate(float *samples) const;

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/chcdemo.cpp

@@ -171 +171 @@
 bool useLODs = true;
 
-DeferredRenderer::SAMPLING_METHOD samplingMethod = DeferredRenderer::POISSON;
+DeferredRenderer::SAMPLING_METHOD samplingMethod = DeferredRenderer::SAMPLING_POISSON;
 
 bool useAdvancedShading = false;
@@ -1180 +1180 @@
         case 'P':
         case 'p':
-                if (samplingMethod == DeferredRenderer::GAUSS)
-                        samplingMethod = DeferredRenderer::POISSON;
-                else
-                        samplingMethod = DeferredRenderer::GAUSS;
+                samplingMethod = DeferredRenderer::SAMPLING_METHOD((samplingMethod + 1) % 3);
+                cout << "ssao sampling method: " << samplingMethod << endl;
                 break;
         case 'Y':

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaderenv.h

@@ -10 +10 @@
 //#define SAMPLE_INTENSITY 40.0f
 
-// for quadradtc falloff
-//#define SAMPLE_INTENSITY 0.28f
+// for quadratic falloff
 #define SAMPLE_INTENSITY 0.32f
-//#define SAMPLE_INTENSITY 2.4f
+//#define SAMPLE_INTENSITY 0.85f
+//#define SAMPLE_INTENSITY 5.0f
 
+//#define AREA_SIZE 15e-1f
 //#define AREA_SIZE 25e-1f
-//#define AREA_SIZE 6e-1f
 #define AREA_SIZE 8e-1f
-//#define AREA_SIZE 5e-1f
 
 #define VIEW_CORRECTION_SCALE 0.0f
 //#define VIEW_CORRECTION_SCALE 0.1f
 
-//#define DISTANCE_SCALE 5e-7f
+//#define DISTANCE_SCALE 1e-4f
 #define DISTANCE_SCALE 1e-6f
-//#define DISTANCE_SCALE 0.0f
+//#define DISTANCE_SCALE 1e-8f
 
 #define ILLUM_INTENSITY 5e-1f;