use cosin-weighted hemisphere sampling instead

NJUCG · Jul 21, 2024 · 3f63dbe · 3f63dbe
1 parent 1800ce2
commit 3f63dbe
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Showing 8 changed files with 56 additions and 24 deletions.
diff --git a/scenes/gold-teapot/models/Mesh000.obj → scenes/micrograin-teapot/models/Mesh000.obj b/scenes/gold-teapot/models/Mesh000.obj → scenes/micrograin-teapot/models/Mesh000.obj
diff --git a/scenes/gold-teapot/models/Mesh001.obj → scenes/micrograin-teapot/models/Mesh001.obj b/scenes/gold-teapot/models/Mesh001.obj → scenes/micrograin-teapot/models/Mesh001.obj
diff --git a/scenes/gold-teapot/scene.json → scenes/micrograin-teapot/scene.json b/scenes/gold-teapot/scene.json → scenes/micrograin-teapot/scene.json
@@ -6,16 +6,34 @@
       "type":"porousLayerMicrograin",
       "bulkMaterial":
       {
-        "name":"plastic",
-        "albedo": 0.9,
-        "type" : "plastic"
+        "name":"conductor",
+        "type":"conductor",
+        "albedo":"textures/rustyMetal.jpg",
+        "eta":[2,2,2],
+        "k":[0,0,0],
+        "roughness":0.3,
+        "distribution":"ggx"
       },
       "micrograinType":"conductor",
-      "tau0":0.99,
+      "tau0":0.3,
       "beta":0.8,
       "R0":[0.588,0.294,0.001],
       "k":[0,0,0]
     },
+    {
+        "name":"conductor",
+        "type":"conductor",
+        "albedo":"textures/rustyMetal.jpg",
+        "eta":[2,2,2],
+        "k":[0,0,0],
+        "roughness":0.3,
+        "distribution":"ggx"
+    },
+    {
+        "name":"plastic",
+        "albedo":0.9,
+        "type":"plastic"
+    },
     {
       "name": "Floor",
       "albedo": {
@@ -116,7 +134,7 @@
     "enable_volume_light_sampling": true
   },
   "renderer": {
-    "output_file": "goldteapot",
+    "output_file": "micrograinTeapot",
     "resume_render_file": "RenderState.dat",
     "overwrite_output_files": false,
     "adaptive_sampling": true,
@@ -127,6 +145,6 @@
     "spp_step": 16,
     "checkpoint_interval": "0",
     "timeout": "0",
-    "hdr_output_file": "dustteapot.exr"
+    "hdr_output_file": "micrograinTeapot.exr"
   }
 }
diff --git a/scenes/gold-teapot/textures/envmap.hdr → scenes/micrograin-teapot/textures/envmap.hdr b/scenes/gold-teapot/textures/envmap.hdr → scenes/micrograin-teapot/textures/envmap.hdr
diff --git a/scenes/gold-teapot/textures/fangzexia.jpg → .../micrograin-teapot/textures/fangzexia.jpg b/scenes/gold-teapot/textures/fangzexia.jpg → .../micrograin-teapot/textures/fangzexia.jpg
diff --git a/scenes/gold-teapot/textures/rustyMetal.jpg → ...micrograin-teapot/textures/rustyMetal.jpg b/scenes/gold-teapot/textures/rustyMetal.jpg → ...micrograin-teapot/textures/rustyMetal.jpg
diff --git a/scenes/gold-teapot/textures/tau0.png → scenes/micrograin-teapot/textures/tau0.png b/scenes/gold-teapot/textures/tau0.png → scenes/micrograin-teapot/textures/tau0.png
diff --git a/src/FunctionLayer/Material/BxDF/PorousLayerBxDF.cpp b/src/FunctionLayer/Material/BxDF/PorousLayerBxDF.cpp
@@ -9,32 +9,46 @@ Spectrum PourousLayerBxDF::f(const Vec3d &out, const Vec3d &in) const {
     double beta = micrograinBRDF->GetBeta();
 
     double w = getMicrograinWeight(tau0, beta, CosTheta(in), CosTheta(out));
-    return micrograinBRDF->f(out, in) + (1. - w) * bulkBxDF->f(out, in);
+    return w * micrograinBRDF->f(out, in) + (1. - w) * bulkBxDF->f(out, in);
 }
 
 double PourousLayerBxDF::pdf(const Vec3d &out, const Vec3d &in) const {
-    double tau0 = micrograinBRDF->GetTau0();
-    double beta = micrograinBRDF->GetBeta();
+    /*double tau0 = micrograinBRDF->GetTau0();
+    double beta = micrograinBRDF->GetBeta();*/
 
-    // double w = getMicrograinWeight(tau0, beta, CosTheta(in), CosTheta(out));
-    double w = 0.5;
-    return micrograinBRDF->pdf(out, in) + (1. - w) * bulkBxDF->pdf(out, in);
+    // double w = getMicrograinWeight(tau0, beta, CosTheta(in), CosTheta(out));*/
+    /*double w = tau0;
+    return w * micrograinBRDF->pdf(out, in) + (1. - w) * bulkBxDF->pdf(out, in);*/
+
+    return CosTheta(in) / fm::pi_d;
 }
 
 BxDFSampleResult PourousLayerBxDF::sample(const Vec3d &out, const Point2d &sample) const {
-    double tau0 = micrograinBRDF->GetTau0();
-    double beta = micrograinBRDF->GetBeta();
+    // double tau0 = micrograinBRDF->GetTau0();
+    // double beta = micrograinBRDF->GetBeta();
+
+    ////double w = getMicrograinWeight(tau0, beta, CosTheta(in), CosTheta(out));
+    // BxDFSampleResult result;
+    // double w = tau0;
+    // if (rand() * 1.0 / RAND_MAX < w) {
+    //     result = micrograinBRDF->sample(out, sample);
+    // } else {
+    //     result = bulkBxDF->sample(out, sample);
+
+    //}
+    // result.bxdfSampleType = BXDFType(BXDF_REFLECTION | BXDF_GLOSSY);
+    // result.s = f(out, result.directionIn);
+    // result.pdf = pdf(out, result.directionIn);
+    // return result;
+
+    double theta = fm::acos(fm::sqrt(1 - sample[0]));
+    double phi = 2 * fm::pi_d * sample[1];
+    Vec3d in = {fm::cos(phi) * fm::sin(theta), fm::sin(phi) * fm::sin(theta), fm::cos(theta)};
 
-    // double w = getMicrograinWeight(tau0, beta, CosTheta(in), CosTheta(out));
     BxDFSampleResult result;
-    double w = 0.5;
-    if (rand() * 1.0 / RAND_MAX < w) {
-        result = micrograinBRDF->sample(out, sample);
-    } else {
-        result = bulkBxDF->sample(out, sample);
-    }
-    result.bxdfSampleType = BXDFType(BXDF_REFLECTION | BXDF_GLOSSY);
-    result.s = f(out, result.directionIn);
-    result.pdf = pdf(out, result.directionIn);
+    result.pdf = pdf(out, in);
+    result.s = f(out, in);
+    result.bxdfSampleType = BXDFType(BXDF_GLOSSY | BXDF_REFLECTION);
+    result.directionIn = in;
     return result;
 }