Update hierarchical integrator to consider both indirect and direct l…

…ighting at sample points.
tatsy · Mar 21, 2016 · c66c084 · c66c084
1 parent b7930be
commit c66c084
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Showing 6 changed files with 261 additions and 247 deletions.
diff --git a/example/pathtracing_example.cc b/example/pathtracing_example.cc
@@ -36,8 +36,8 @@ int main(int argc, char **argv) {
     //VolPathIntegrator integr(camera, sampler);
     //PathIntegrator integr(camera, sampler);
 
-    IrradCacheIntegrator integr(camera, sampler);
-    //HierarchicalIntegrator integr(camera, sampler);
+    //IrradCacheIntegrator integr(camera, sampler);
+    HierarchicalIntegrator integr(camera, sampler);
     //PPMProbIntegrator integr(camera, sampler);
     integr.render(scene, params);
 

diff --git a/sources/bxdf/bssrdf.cc b/sources/bxdf/bssrdf.cc
@@ -384,7 +384,7 @@ double DiffusionReflectance::Ft(const Vector3d& w) const {
 double DiffusionReflectance::Fdr() const {
     if (eta_ >= 1.0) {
         return -1.4399 / (eta_ * eta_) + 0.7099 / eta_ + 0.6681 +
-               0.0636f * eta_;
+               0.0636 * eta_;
     } else {
         return -0.4399f + 0.7099 / eta_ - 0.3319 / (eta_ * eta_) +
                0.0636 / (eta_ * eta_ * eta_);    

diff --git a/sources/core/sampling.cc b/sources/core/sampling.cc
@@ -184,6 +184,87 @@ void sampleUniformHemisphere(const Normal3d& normal, Vector3d* direction, const
     *direction = (u * cos(t) * z2s + v * sin(t) * z2s + w * sqrt(1.0 - z2)).normalized();        
 }
 
+void samplePoissonDisk(const Scene& scene, const Point3d& pCamera,
+                       double minDist, std::vector<Interaction>* points) {
+    std::vector<Triangle> tris;
+    for (const auto& p : scene.primitives()) {
+        if (p->material()->isSubsurface()) {
+            auto ts = p->triangulate();
+            tris.insert(tris.end(), ts.begin(), ts.end());
+        }
+    }
+
+    // Initialize utility variables in this method
+    const auto seed = static_cast<unsigned int>(time(0));
+    Random rng(seed);
+
+    // Sample random points on trimesh
+    Bounds3d bounds;
+    std::vector<Point3d> candPoints;
+    std::vector<Normal3d> candNormals;
+    for (int i = 0; i < tris.size(); i++) {
+        const Triangle& tri = tris[i];
+        const double A = tri.area();
+        const int nSample = static_cast<int>(std::ceil(4.0 * A / (minDist * minDist)));
+        for (int k = 0; k < nSample; k++) {
+            double u = rng.nextReal();
+            double v = rng.nextReal();
+            if (u + v >= 1.0) {
+                u = 1.0 - u;
+                v = 1.0 - v;
+            }
+            Point3d  p = (1.0 - u - v) * tri[0] + u * tri[1] + v * tri[2];
+            Normal3d n = (1.0 - u  -v) * tri.normal(0) + u * tri.normal(1) + 
+                         v * tri.normal(2);
+            candPoints.push_back(p);
+            candNormals.push_back(n);
+            bounds.merge(p);
+        }
+    }
+
+    // Create hash grid
+    const int numCands = static_cast<int>(candPoints.size());
+    Vector3d bsize = bounds.posMax() - bounds.posMin();
+    const double scale = 1.0 / (2.0 * minDist);
+    const int numPoints = candPoints.size();
+    HashGrid<int> hashgrid;
+    hashgrid.init(numPoints, scale, bounds);
+
+    RandomQueue<int> que;
+    for (int i = 0; i < numCands; i++) {
+        que.push(i);
+    }
+
+    std::vector<int> sampledIDs;
+    Vector3d margin(2.0 * minDist, 2.0 * minDist, 2.0 * minDist);
+    while (!que.empty()) {
+        int id = que.pop();
+        Point3d v = candPoints[id];
+        const std::vector<int>& cellvs = hashgrid[v];
+
+        bool accept = true;
+        for (int k = 0; k < cellvs.size(); k++) {
+            if ((candPoints[cellvs[k]] - v).squaredNorm() < minDist * minDist) {
+                accept = false;
+                break;
+            }
+        }
+
+        if (accept) {
+            Point3d boxMin = v - margin;
+            Point3d boxMax = v + margin;
+            hashgrid.add(id, boxMin, boxMax);
+            sampledIDs.push_back(id);
+        }
+    }
+
+    // Store sampled points
+    std::vector<int>::iterator it;
+    for (auto i : sampledIDs) {
+        points->emplace_back(candPoints[i], candNormals[i]);
+    }
+}
+
 void samplePoissonDisk(const Scene& scene, const Point3d& pCamera,
                        double minDist, std::vector<SurfaceInteraction>* points) {
     // Initialize utility variables in this method

diff --git a/sources/core/sampling.h b/sources/core/sampling.h
@@ -63,6 +63,10 @@ SPICA_EXPORTS Vector3d sampleCosineHemisphere(const Point2d& rands);
 SPICA_EXPORTS inline double   cosineHemispherePdf(double cosTheta) { return cosTheta * INV_PI; }
 SPICA_EXPORTS void sampleUniformHemisphere(const Normal3d& normal, Vector3d* direction, const Point2d& rands);
 
+SPICA_EXPORTS
+void samplePoissonDisk(const Scene& scene, const Point3d& pCamera, 
+                       double minDist, std::vector<Interaction>* points);
+
 SPICA_EXPORTS
 void samplePoissonDisk(const Scene& scene, const Point3d& pCamera, 
                        double minDist, std::vector<SurfaceInteraction>* points);