Add Heterogeneous implementation.

Assignments/Assignment2/Application2.cpp

@@ -1,9 +1,13 @@
 #include "Application2.h"
 #include "embree4/rtcore_common.h"
 #include "helper.hpp"
+#include "lights/light.h"
+#include "math/vec2.h"
+#include "math/vec3fa.h"
 #include "random_sampler.hpp"
 #include "ray.hpp"
 #include <cmath>
+#include <cstdio>
 
 #define EPS 0.0001f
 
@@ -135,11 +139,126 @@ Vec3fa Application2::renderPixel(float x, float y, const ISPCCamera& camera, Ray
         return renderPixelOrig(x, y, camera, stats, sampler);
     } else if (selected == 1) {
         return renderPixelHomogeneous(x, y, camera, stats, sampler);
+    } else if (selected == 2) {
+        return renderPixelHeterogeneous(x, y, camera, stats, sampler);
     } else {
         return Vec3fa(0.0f);
     }
 }
 
+Vec3fa Application2::renderPixelHeterogeneous(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSampler& sampler) {
+
+    Vec3fa L = Vec3fa(0.0f);
+    Vec3fa Lw = Vec3fa(1.0f);
+
+    bool in_volume = false;
+    float max_density = 1.32 * density; // tested
+
+    /* initialize ray */
+    Ray ray(Vec3fa(camera.xfm.p), Vec3fa(normalize(x * camera.xfm.l.vx + y * camera.xfm.l.vy + camera.xfm.l.vz)), 0.0f,
+            inf);
+
+    for (int i = 0; i < ray_depth; i++) {
+
+
+        /* intersect ray with scene */
+        RTCIntersectArguments iargs;
+        rtcInitIntersectArguments(&iargs);
+        iargs.feature_mask = RTC_FEATURE_FLAG_TRIANGLE;
+        rtcIntersect1(data.g_scene, RTCRayHit_(ray), &iargs);
+        RayStats_addRay(stats);
+
+        const Vec3fa wo = neg(ray.dir);
+
+        float t;
+        if (!in_volume | (density == 0)) {
+            t = inf;
+        } else {
+            // printf("%f\n", density);
+            t = - std::log(1.0 - RandomSampler_get1D(sampler)) / max_density;
+        }
+
+        if (t > 0.0 && t < ray.tfar) {
+
+            if (ray.geomID == RTC_INVALID_GEOMETRY_ID) {
+                break;
+            }
+
+            float r = RandomSampler_get1D(sampler);
+            Vec3fa p = ray.org + t * ray.dir;
+            // printf("%f\t%f\t(%f,%f,%f)\n", t, ray.tfar, p.x, p.y, p.z);
+            float s = data.densityGrid->sampleW(p);
+            // if (s != -1.0) {
+            //     printf("(%f,%f,%f)\tt: %f\ttfar: %f\tr: %f\t%f\ts: %f\t%f\tp:%f\n",p.x, p.y, p.z, t, ray.tfar, r, r * max_density, s, s * density, (s * density) / max_density);
+            // }
+            // if (s > 0.5) {
+            //     printf("(%f,%f,%f)\tr: %f\t%f\ts: %f\t%f\tp:%f\n",p.x, p.y, p.z , r, r * max_density, s, s * density, (s * density) / max_density);
+            // }
+
+            if (RandomSampler_get1D(sampler) * max_density < s * density) {
+
+                
+                float pdf;
+                Vec3fa o = sample_phase_function(-ray.dir, scattering_parameter, RandomSampler_get2D(sampler), pdf);
+
+                float temp = data.tempGrid->sampleW(p); // Sample density from the grid
+                // float temp = 20;
+                float redWavelength = 700;
+                float greenWavelength = 530;
+                float blueWavelength = 470;
+                Vec3fa emissive = Vec3fa(0.0, 0.0, 0.0);
+                if (temp != -1.0f && temp > 0.001) {
+                    temp *= tempearture_multiplier;
+                    emissive = Vec3f(blackbody_radiance_normalized(redWavelength, temp),
+                                     blackbody_radiance_normalized(greenWavelength, temp),
+                                     blackbody_radiance_normalized(blueWavelength, temp));
+                }
+                L += Lw * absorbtion * emissive;
+                Lw *= 1.0 - absorbtion;
+
+                ray = Ray(ray.org + t * ray.dir,o,EPS,inf);
+                
+            } else {
+                // printf("volume(%f,%f,%f), t: %f, tfar: %f\n", ray.org.x, ray.org.y, ray.org.z, t, ray.tfar);
+                ray = Ray(ray.org + t * ray.dir, ray.dir, EPS, inf);
+                i--;
+            }
+
+        } else if (ray.geomID != RTC_INVALID_GEOMETRY_ID) {
+
+            Sample sample = createSample(ray);
+            int matId = data.scene->geometries.at(ray.geomID)->materialID;
+            unsigned lightID = data.scene->geometries.at(ray.geomID)->lightID;
+            
+            if (lightID != unsigned(-1)) {
+                const Light* l = data.scene->lights[lightID];
+                Light_EvalRes evalRes = Lights_eval(l, sample, -wo);
+                L += Lw * evalRes.value;
+                break;
+            }
+            
+            /* calculate BRDF */
+            BRDF brdf;
+            std::vector<Material *> material_array = data.scene->materials;
+            Material__preprocess(material_array, matId, brdf, wo, sample);
+            if (brdf.name == "default") {
+                // printf("surface\n");
+
+                in_volume = !in_volume;
+                // in_volume = dot(normalize(ray.Ng), ray.dir) < 0;
+                
+                ray = Ray(ray.org + ray.tfar * ray.dir, ray.dir, EPS, inf);
+
+                i--;
+
+            }
+        }
+
+    }
+    
+    return L;
+}
+
 Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSampler& sampler) {
     /* radiance accumulator and weight */
     Vec3fa L = Vec3fa(0.0f);
@@ -162,16 +281,12 @@ Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera&
 
         const Vec3fa wo = neg(ray.dir);
 
-        float mu_t = mu_a + mu_s;
-        if (!in_volume) {
-            mu_t = 0;
-        }
         float t;
-        if (mu_t == 0) {
+        if (!in_volume | (density == 0)) {
             t = inf;
         } else {
-            // printf("%f\n", mu_t);
+            // printf("%f\n", density);
-            t = - std::log(1.0 - RandomSampler_get1D(sampler)) / mu_t;
+            t = - std::log(1.0 - RandomSampler_get1D(sampler)) / density;
         }
     
         // if (t != t | t <= 0) {
@@ -222,7 +337,7 @@ Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera&
 
                 if (shadow.geomID == RTC_INVALID_GEOMETRY_ID) {
                     if (shadow_in_volume) {
-                        Lwscatter *= std::pow(M_E, - mu_t * (shadow.tfar - shadow.tnear()));
+                        Lwscatter *= std::pow(M_E, - density * (shadow.tfar - shadow.tnear()));
                     }
                     break;
                 }
@@ -237,7 +352,7 @@ Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera&
                 if (brdf.name == "default") {
                     
                     if (shadow_in_volume) {
-                        Lwscatter *= std::pow(M_E, - mu_t * (shadow.tfar - shadow.tnear()));
+                        Lwscatter *= std::pow(M_E, - density * (shadow.tfar - shadow.tnear()));
                     }
 
                     shadow_in_volume = dot(normalize(shadow.Ng), shadow.dir) < 0;
@@ -262,7 +377,7 @@ Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera&
             /* add light contribution if not occluded (NEE) */
             if (Lwscatter > 0.0) {
                 // L += Lw * light_diffuse * ls.weight;
-                L += Lw * Lwscatter * scatter * (mu_s / mu_t) * ls.weight * dot(sample.Ng, ls.dir) / data.scene->lights.size();
+                L += Lw * Lwscatter * scatter * (1.0 - absorbtion) * ls.weight * dot(sample.Ng, ls.dir) / data.scene->lights.size();
                 // L += Lw * light_diffuse * ls.weight/ data.scene->lights.size();
             }
 
@@ -271,7 +386,7 @@ Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera&
             float pdf;
             Vec3fa o = sample_phase_function(-ray.dir, scattering_parameter, RandomSampler_get2D(sampler), pdf);
 
-            Lw *= mu_s / mu_t;
+            Lw *= 1.0 - absorbtion;
 
             ray = Ray(ray.org + t * ray.dir,o,EPS,inf);
             
@@ -343,7 +458,7 @@ Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera&
 
                     if (shadow.geomID == RTC_INVALID_GEOMETRY_ID) {
                         if (shadow_in_volume) {
-                            Lwscatter *= std::pow(M_E, - mu_t * (shadow.tfar - shadow.tnear()));
+                            Lwscatter *= std::pow(M_E, - density * (shadow.tfar - shadow.tnear()));
                         }
                         break;
                     }
@@ -358,7 +473,7 @@ Vec3fa Application2::renderPixelHomogeneous(float x, float y, const ISPCCamera&
                     if (brdf.name == "default") {
                         
                         if (shadow_in_volume) {
-                            Lwscatter *= std::pow(M_E, - mu_t * (shadow.tfar - shadow.tnear()));
+                            Lwscatter *= std::pow(M_E, - density * (shadow.tfar - shadow.tnear()));
                         }
 
                         shadow_in_volume = dot(normalize(shadow.Ng), shadow.dir) < 0;

Assignments/Assignment2/Application2.h

@@ -13,6 +13,7 @@ private:
     Vec3fa renderPixel(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSampler& sampler) override;
     Vec3fa renderPixelOrig(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSampler& sampler);
     Vec3fa renderPixelHomogeneous(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSampler& sampler);
+    Vec3fa renderPixelHeterogeneous(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSampler& sampler);
 
     void drawGUI() override {
         ImGui::Checkbox("Bounding Box", &boundingBox);
@@ -23,19 +24,22 @@ private:
             ray_depth = 1;
         }
 
-        const char* items[] = {"Original", "Homogeneous"};
+        const char* items[] = {"Original", "Homogeneous", "Heterogeneous"};
-        if (ImGui::Combo("Version", &selected, items, 2))
+        if (ImGui::Combo("Version", &selected, items, 3))
             clear();
 
-        if (ImGui::SliderFloat("mu_a", &mu_a, 0.0, 1.0))
+        if (ImGui::SliderFloat("density", &density, 0.0, 1.0))
             clear();
 
-        if (ImGui::SliderFloat("mu_s", &mu_s, 0.0, 1.0))
+        if (ImGui::SliderFloat("absorbtion", &absorbtion, 0.0, 1.0))
             clear();
         
         if (ImGui::SliderFloat("scattering parameter", &scattering_parameter, -1.0, 1.0))
             clear();
 
+        if (ImGui::SliderFloat("temperature", &tempearture_multiplier, 1.0, 10000.0))
+            clear();
+
         const char* scenes[] = {"Gnome", "Horse", "Heterogenous"};
         if (ImGui::Combo("Scenes", &scene, scenes, 3)) {
             Data_Destructor(&data);
@@ -70,7 +74,8 @@ private:
     bool boundingBox = true;
     int selected = 0;
     int scene = 0;
-    float mu_a = 0.0;
+    float density = 0.0;
-    float mu_s = 0.0;
+    float absorbtion = 0.0;
+    float tempearture_multiplier = 1000.0;
     float scattering_parameter = 0.4;
 };

Framework/include/application.h

@@ -130,7 +130,7 @@ protected:
     double clickX = 0;
     double clickY = 0;
 
-    float speed = 10;
+    float speed = 400;
     Vec3f moveDelta = {0, 0, 0};
 
     RayStats* g_stats = nullptr;

Framework/scenegraph/grid.h

@@ -54,6 +54,11 @@ namespace embree
 
 			data.resize(res.x * res.y * res.z);
 			file.read(reinterpret_cast<char*>(data.data()), data.size() * sizeof(float));
+			float max = 0;
+			for (size_t i = 0; i < res.x * res.y * res.z; i++) {
+				max = std::max(data[i], max);
+			}
+			printf("max:\t%f\n", max);
 			file.close();
 		}