Changeset 2739 for GTP

Timestamp:

06/05/08 02:49:49 (17 years ago)

Author:

mattausch

Message:

worked on randomized sampling

Location:

GTP/trunk/Lib/Vis/Preprocessing/src

Files:

• GvsPreprocessor.cpp (modified) (10 diffs)
• GvsPreprocessor.h (modified) (5 diffs)

GTP/trunk/Lib/Vis/Preprocessing/src/GvsPreprocessor.cpp

@@ -176 +176 @@
         // discrepancy between predicted and actual hit point large => this is likely to be a discontinuity
 
-        // matt: problem: this does only find CLOSER discontinuities, but not discontinuities which are FARTHER away
+        // matt: problem: this only finds CLOSER discontinuities, but not discontinuities which are FARTHER away
         if ((predictedLen - len) < mThreshold)
-        //if ((fabs(predictedLen - len) < mThreshold)
         // q: rather use relative distance?
         //if ((predictedLen / len) < mThreshold)
@@ -208 +207 @@
                         CastRayBundle16(simpleRay, reverseRays, scale);
         }
+
+        mGvsStats.mReverseSamples += (int)reverseRays.size();
+
+        EnqueueRays(reverseRays);
+
+        return (int)reverseRays.size();
+}
+
+
+int GvsPreprocessor::CheckDiscontinuity2(const VssRay &currentRay,
+                                                                                 const Triangle3 &hitTriangle,
+                                                                                 const VssRay &oldRay)
+{
+        // the predicted hitpoint is the point where the ray would have intersected the hit triangle
+        Vector3 predictedHit = CalcPredictedHitPoint(currentRay, hitTriangle, oldRay);
+
+        float predictedLen = Magnitude(predictedHit - currentRay.mOrigin);
+        float len = Magnitude(currentRay.mTermination - currentRay.mOrigin);
+        
+        // discrepancy between predicted and actual hit point large 
+        // => this is likely to be a discontinuity
+        if (fabs(predictedLen - len) < mThreshold)
+                return 0;
+
+        static SimpleRayContainer simpleRays;
+        simpleRays.clear();
+
+        CreateRandomizedReverseRays(currentRay.mOrigin, predictedHit, hitTriangle, simpleRays, 16);
+
+        static VssRayContainer reverseRays;
+        reverseRays.clear();
+        CastRays(simpleRays, reverseRays, false, false);
 
         mGvsStats.mReverseSamples += (int)reverseRays.size();
@@ -487 +518 @@
         }
 
+        //////////
+        //-- fill up simple rays with random rays so we can cast 16 rays at a time
+
+        const int numRandomRays = 16 - (int)simpleRays.size();
+        GenerateRays(numRandomRays, *mDistribution, simpleRays, sInvalidSamples);
+
+        generationTimer.Exit();
+
+
+        /////////////////////
+        //-- cast rays to vertices and determine visibility
+        
+        static VssRayContainer vssRays;
+        vssRays.clear();
+
+        // for the original implementation we don't cast double rays
+        const bool castDoubleRays = !mPerViewCell;
+        // cannot prune invalid rays because we have to compare adjacent rays
+        const bool pruneInvalidRays = false;
+
+        //gvsTimer.Entry();
+        castTimer.Entry();
+
+        CastRays(simpleRays, vssRays, castDoubleRays, pruneInvalidRays);
+        
+        castTimer.Exit();
+        //gvsTimer.Exit();
+
+        const int numBorderSamples = (int)vssRays.size() - numRandomRays;
+        int castRays = (int)simpleRays.size();
+
+        // handle cast rays
+        EnqueueRays(vssRays);
+
         if (0)
         {
@@ -493 +558 @@
                 dummy.enlargedTriangle = new Polygon3(enlargedTriangle);
                 dummy.originalTriangle = hitTriangle;
+        
                 vizContainer.push_back(dummy);
-        }
-
-        
-        //////////
-        //-- fill up simple rays with random rays so we can cast 16 rays at a time
-
-        const int numRandomRays = 16 - (int)simpleRays.size();
-
-        if (!mUseDeterministicGvs)
-        {
-                if (0)
-                {
-                        SimpleRay mainRay = SimpleRay(currentRay.GetOrigin(), 
-                                                          currentRay.GetNormalizedDir(), 
-                                                                                  SamplingStrategy::GVS, 
-                                                                                  1.0f);
-                        
-                        GenerateJitteredRays(simpleRays, mainRay, numRandomRays, 0, 0.01f);
-                }
-                else
-                        GenerateImportanceSamples(currentRay, hitTriangle, numRandomRays, simpleRays);
-        }
-        else
-                GenerateRays(numRandomRays, *mDistribution, simpleRays, sInvalidSamples);
-
-        generationTimer.Exit();
-
-
-        /////////////////////
-        //-- cast rays to vertices and determine visibility
-        
-        static VssRayContainer vssRays;
-        vssRays.clear();
-
-        // for the original implementation we don't cast double rays
-        const bool castDoubleRays = !mPerViewCell;
-        // cannot prune invalid rays because we have to compare adjacent rays
-        const bool pruneInvalidRays = false;
-
-        //gvsTimer.Entry();
-        castTimer.Entry();
-
-        CastRays(simpleRays, vssRays, castDoubleRays, pruneInvalidRays);
-        
-        castTimer.Exit();
-        //gvsTimer.Exit();
-
-        const int numBorderSamples = (int)vssRays.size() - numRandomRays;
-        int castRays = (int)simpleRays.size();
-
-        // handle cast rays
-        EnqueueRays(vssRays);
-
-        if (0)
-        {
+        
                 // set flags
                 VssRayContainer::const_iterator rit, rit_end = vssRays.end();
@@ -556 +568 @@
         }
 
-        for (size_t i = 0; i < vssRays.size(); ++ i)
-        {
-                // check for discontinuity and cast reverse rays if necessary
-                castRays += CheckDiscontinuity(*vssRays[i], hitTriangle, currentRay);
-        }
-        
-
     // recursivly subdivide each edge
         for (int i = 0; i < numBorderSamples; ++ i)
         {
+                castRays += CheckDiscontinuity(*vssRays[i], hitTriangle, currentRay);
+
                 castRays += SubdivideEdge(hitTriangle,
                                                                   enlargedTriangle[i], 
@@ -638 +645 @@
         const int numRandomRays = 16 - ((int)simpleRays.size() % 16);
 
-                if (!mUseDeterministicGvs)
-        {
-                if (0)
-                {
-                        SimpleRay mainRay = SimpleRay(currentRay.GetOrigin(), 
-                                                          currentRay.GetNormalizedDir(), 
-                                                                                  SamplingStrategy::GVS, 
-                                                                                  1.0f);
-                        
-                        GenerateJitteredRays(simpleRays, mainRay, numRandomRays, 0, 0.01f);
-                }
-                else
-                        GenerateImportanceSamples(currentRay, hitTriangle, numRandomRays, simpleRays);
-        }
-        else
-                GenerateRays(numRandomRays, *mDistribution, simpleRays, sInvalidSamples);
-
+        GenerateImportanceSamples(currentRay, hitTriangle, numRandomRays, simpleRays);
+        
         generationTimer.Exit();
 
@@ -689 +681 @@
         {
                 // check for discontinuity and cast reverse rays if necessary
-                castRays += CheckDiscontinuity(*vssRays[i], hitTriangle, currentRay);
+                castRays += CheckDiscontinuity2(*vssRays[i], hitTriangle, currentRay);
         }
 
@@ -794 +786 @@
 
         //////////////
-        //-- for per view cell sampling, we must check for intersection
+        //-- for per view cell sampling, we must intersect
         //-- with the current view cell
 
     if (mPerViewCell)
         {
-                // send ray to view cell
-                static Ray ray;
-
-                ray.Clear();
-                ray.Init(newOrigin, -newDir, Ray::LOCAL_RAY);
-                
-                // check if ray intersects view cell
-                if (!mCurrentViewCell->CastRay(ray))
+                if (!IntersectViewCell(newOrigin, newDir))
                         return false;
-
-                Ray::Intersection &hit = ray.intersections[0];
-        
-                // the ray starts from the view cell
-                newOrigin = ray.Extrap(hit.mT);
         }
 
         reverseRay = SimpleRay(newOrigin, newDir, SamplingStrategy::GVS, 1.0f);
+
+        return true;
+}
+
+
+bool GvsPreprocessor::IntersectViewCell(Vector3 &origin, Vector3 &dir) const
+{
+        // send ray to view cell
+        static Ray testRay;
+
+        testRay.Clear();
+        testRay.Init(origin, -dir, Ray::LOCAL_RAY);
+
+        // check if ray intersects view cell
+        if (!mCurrentViewCell->CastRay(testRay))
+                return false;
+
+        Ray::Intersection &hit = testRay.intersections[0];
+
+        // the ray starts from the view cell
+        origin = testRay.Extrap(hit.mT);
 
         return true;
@@ -908 +909 @@
                 mRayQueue.pop();
                 
-                if (0)
+                if (mUseDeterministicGvs)
                         castSamples += AdaptiveBorderSampling(*ray);
                 else
                         castSamples += AdaptiveBorderSamplingOpt(*ray);
+
                 // note: don't have to delete because handled by ray pool
         }
@@ -2033 +2035 @@
 
 
-}
+void GvsPreprocessor::CreateRandomizedReverseRays(const Vector3 &origin, 
+                                                                                                  const Vector3 &termination, 
+                                                                                                  const Triangle3 &triangle,                   
+                                                                                                  SimpleRayContainer &rays, 
+                                                                                                  int number)
+{
+        size_t currentNumber = rays.size();
+
+        while ((rays.size() - currentNumber) < number)
+        {
+                SimpleRay ray;
+                if (CreateRandomizedReverseRay(origin, termination, triangle, ray))
+                        rays.push_back(ray);
+        }
+}
+
+
+bool GvsPreprocessor::CreateRandomizedReverseRay(const Vector3 &origin, 
+                                                                                                 const Vector3 &termination, 
+                                                                                                 const Triangle3 &triangle,                   
+                                                                                                 SimpleRay &ray)
+{
+        Vector3 nd = triangle.GetNormal();
+  
+        // Compute right handed coordinate system from direction
+        Vector3 U, V;
+        nd.RightHandedBase(U, V);
+        
+        float rr[2];
+
+        rr[0] = RandomValue(0, 1);
+        rr[1] = RandomValue(0, 1);
+
+        Vector2 vr2(rr[0], rr[1]);
+        const float sigma = triangle.GetBoundingBox().Radius() * mRadiusOfInfluence;
+        Vector2 gaussvec2;
+
+        GaussianOn2D(vr2, sigma, // input
+                         gaussvec2); // output
+        
+        const Vector3 shift = gaussvec2.xx * U + gaussvec2.yy * V;
+
+        Vector3 newOrigin = origin;
+
+        //cout << "t: " << termination;
+        newOrigin += shift;
+        //cout << " new t: " << termination << endl;
+        Vector3 direction = termination - newOrigin;
+
+        const float len = Magnitude(direction);
+        
+        if (len < Limits::Small)
+                return false;
+  
+        direction /= len;
+
+        if (!IntersectViewCell(newOrigin, direction))
+                return false;
+
+        // $$ jb the pdf is yet not correct for all sampling methods!
+        const float pdf = 1.0f;
+        ray = SimpleRay(newOrigin, direction, SamplingStrategy::GVS, pdf);
+        
+        return true;
+}
+
+
+}

GTP/trunk/Lib/Vis/Preprocessing/src/GvsPreprocessor.h

@@ -121 +121 @@
 
 protected:
-#if 0
-        struct PendingRay
-        {
-                PendingRay(VssRay *ray, const bool d)
-                        : mRay(ray), mFoundDiscontinuity(d) 
-                {}
-
-                VssRay *mRay;
-                bool mFoundDiscontinuity;
-        };
-
-        typedef stack<PendingRay> PendingQueue;
-#endif
+
         typedef stack<VssRay *> RayQueue;
 
@@ -140 +128 @@
                 by the queue and continues as long it finds new visible geometry 
                 (i.e., the queue is     not empty).
-
                 @returns the number of samples cast.
         */
         int ProcessQueue();
-
         /** Generates the rays starting the adaptive visibility sampling process.
         */
         int CastInitialSamples(int numSamples);
-
         /** Uses the information gained from the ray for doing adaptive border sampling.
                 This function tries to find the border of the triangle found visible by the
@@ -163 +148 @@
         */      
         int AdaptiveBorderSampling(const VssRay &currentRay);
+
         int AdaptiveBorderSamplingOpt(const VssRay &currentRay);
         /** The reverse sampling step. It is started once the cast
@@ -179 +165 @@
                                                    const Triangle3 &hitTriangle,
                                                    const VssRay &oldRay);
+        /** Returns true if we sampled a closer triangle than with the previous ray. 
+                Does reverse sampling if gap found.
+        */
+        int CheckDiscontinuity2(const VssRay &currentRay, 
+                                    const Triangle3 &hitTriangle,
+                                                        const VssRay &oldRay);
         /** Adds new samples to the ray queue and classifies them
                 with respect to the previous ray.
@@ -300 +292 @@
 
         void PrepareProbablyVisibleSampling();
+        
+        void CreateRandomizedReverseRays(const Vector3 &origin, 
+                                             const Vector3 &termination, 
+                                                                         const Triangle3 &triangle,                   
+                                                                         SimpleRayContainer &rays, 
+                                                                         int number);
+
+        bool CreateRandomizedReverseRay(const Vector3 &origin, 
+                                            const Vector3 &termination,
+                                                                        const Triangle3 &triangle,
+                                                                        SimpleRay &ray);
+
+        inline bool IntersectViewCell(Vector3 &origin, Vector3 &dir) const;