Add path tracer implementation to application3

Assignments/Assignment3/Application3.cpp

@@ -1,5 +1,7 @@
 #include "Application3.h"
+#include "math/vec3fa.h"
 
+#define EPS 0.01f
 void Application3::initScene() {
     Data_Constructor(&data, 1, 8);
 
@@ -46,7 +48,7 @@ void Application3::causticScene() {
 
 	auto light = new SceneGraph::QuadLightMesh(Vec3fa(0.1, 1.0, 2.0), Vec3fa(-0.1, 1.2, 2.0),
 		Vec3fa(-0.1, 1.0, 2.0), Vec3fa(0.1, 1.2, 2.0),
-		Vec3fa(50, 50, 50));
+		Vec3fa(50, 50, 50) * 10);
 
 	sceneGraph->add(light);
 
@@ -72,6 +74,80 @@ void Application3::causticScene() {
 
 /* task that renders a single screen tile */
 Vec3fa Application3::renderPixel(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSamplerWrapper& sampler) {
+  if (method == 0) {
+    return renderPixelPT(x,y , camera, stats, sampler);
+  } else if (method == 1) {
+    return renderPixelNEE(x,y , camera, stats, sampler);
+  } else {
+    return Vec3fa(0.0);
+  }
+}
+
+Vec3fa Application3::renderPixelPT(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSamplerWrapper& sampler) {
+  /* radiance accumulator and weight */
+    Vec3fa L = Vec3fa(0.0f);
+    Vec3fa Lw = Vec3fa(1.0f);
+
+    /* 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);
+
+        /* shade pixels */
+        if (ray.geomID == RTC_INVALID_GEOMETRY_ID) {
+            break;
+        }
+
+        
+        Vec3fa Ns = normalize(ray.Ng);
+        Sample sample;
+        sample.P = ray.org + ray.tfar * ray.dir;
+        sample.Ng = ray.Ng;
+        sample.Ns = Ns;
+        int matId = data.scene->geometries[ray.geomID]->materialID;
+        unsigned lightID = data.scene->geometries[ray.geomID]->lightID;
+        sample.Ng = face_forward(ray.dir, normalize(sample.Ng));
+        sample.Ns = face_forward(ray.dir, normalize(sample.Ns));
+
+        // evaluate light
+        if (lightID != unsigned(-1)) {
+            const Light* l = data.scene->lights[lightID];
+            Light_EvalRes evalRes = Lights_eval(l, sample, -wo);
+            return Lw * evalRes.value;
+            break;
+        }
+
+        /* calculate BRDF */
+        BRDF brdf;
+        std::vector<Material *> material_array = data.scene->materials;
+        Material__preprocess(material_array, matId, brdf, wo, sample);
+
+
+        Vec2f uv = sampler.get2D();
+        Sample3f wi;
+        Vec3fa diffuse = Material__sample(material_array, matId, brdf, Lw, wo, sample, wi, uv);
+
+        Lw *= diffuse / wi.pdf;
+
+        ray = Ray(sample.P,wi.v,EPS,inf);
+
+    }
+
+    return L;
+}
+
+Vec3fa Application3::renderPixelNEE(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSamplerWrapper& sampler) {
+  
     /* radiance accumulator and weight */
     Vec3fa L = Vec3fa(0.0f);
     Vec3fa Lw = Vec3fa(1.0f);
@@ -80,67 +156,84 @@ Vec3fa Application3::renderPixel(float x, float y, const ISPCCamera& camera, 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);
 
-    /* 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);
+    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);
 
-    /* shade pixels */
+        const Vec3fa wo = neg(ray.dir);
-    if (ray.geomID != RTC_INVALID_GEOMETRY_ID) {
+
+        /* shade pixels */
+        if (ray.geomID == RTC_INVALID_GEOMETRY_ID) {
+            break;
+        }
+
+        
         Vec3fa Ns = normalize(ray.Ng);
         Sample sample;
         sample.P = ray.org + ray.tfar * ray.dir;
         sample.Ng = ray.Ng;
         sample.Ns = Ns;
-        unsigned matId = data.scene->geometries[ray.geomID]->materialID;
+        int matId = data.scene->geometries[ray.geomID]->materialID;
         unsigned lightID = data.scene->geometries[ray.geomID]->lightID;
+        sample.Ng = face_forward(ray.dir, normalize(sample.Ng));
+        sample.Ns = face_forward(ray.dir, normalize(sample.Ns));
 
+        // include direct light on first ray
         if (lightID != unsigned(-1)) {
-            const Light* l = data.scene->lights[lightID];
+            if (i == 0) {
-            Light_EvalRes evalRes = Lights_eval(l, sample, -wo);
+                const Light* l = data.scene->lights[lightID];
-
+                Light_EvalRes evalRes = Lights_eval(l, sample, -wo);
-            L += evalRes.value;
+                L += Lw * evalRes.value;
-        } else {
-            sample.Ng = face_forward(ray.dir, normalize(sample.Ng));
-            sample.Ns = face_forward(ray.dir, normalize(sample.Ns));
-
-            /* calculate BRDF */
-            BRDF brdf;
-            std::vector<Material *> material_array = data.scene->materials;
-            Material__preprocess(material_array, matId, brdf, wo, sample);
-
-            /* sample BRDF at hit point */
-            Sample3f wi1;
-            Material__sample(material_array, matId, brdf, Lw, wo, sample, wi1, sampler.get2D());
-
-            int id = (int)(sampler.get1D()* data.scene->lights.size());
-            if (id == data.scene->lights.size())
-                id = data.scene->lights.size() - 1;
-            const Light* l = data.scene->lights[id];
-
-            Light_SampleRes ls = Lights_sample(l, sample, sampler.get2D());
-
-            Vec3fa diffuse = Material__eval(material_array, matId, brdf, wo, sample, ls.dir);
-
-            /* initialize shadow ray */
-            Ray shadow(sample.P, ls.dir, 0.001f, ls.dist-0.001f, 0.0f);
-
-            /* trace shadow ray */
-            RTCOccludedArguments sargs;
-            rtcInitOccludedArguments(&sargs);
-            sargs.feature_mask = RTC_FEATURE_FLAG_TRIANGLE;
-            rtcOccluded1(data.g_scene, RTCRay_(shadow), &sargs);
-            RayStats_addShadowRay(stats);
-
-            /* add light contribution if not occluded */
-            if (shadow.tfar >= 0.0f) {
-                L += diffuse * ls.weight;
             }
+            break;
         }
+
+        /* calculate BRDF */
+        BRDF brdf;
+        std::vector<Material *> material_array = data.scene->materials;
+        Material__preprocess(material_array, matId, brdf, wo, sample);
+
+        /* Light ray  */
+        int id = (int)(sampler.get1D() * data.scene->lights.size());
+        if (id == data.scene->lights.size())
+            id = data.scene->lights.size() - 1;
+        const Light* l = data.scene->lights[id];
+
+        Light_SampleRes ls = Lights_sample(l, sample, sampler.get2D());
+
+        Vec3fa light_diffuse = Material__eval(material_array, matId, brdf, wo, sample, ls.dir);
+
+        /* initialize shadow ray */
+        Ray shadow(sample.P, ls.dir, EPS, ls.dist - EPS, 0.0f);
+
+        /* trace shadow ray */
+        RTCOccludedArguments sargs;
+        rtcInitOccludedArguments(&sargs);
+        sargs.feature_mask = RTC_FEATURE_FLAG_TRIANGLE;
+        rtcOccluded1(data.g_scene, RTCRay_(shadow), &sargs);
+        RayStats_addShadowRay(stats);
+
+        /* add light contribution if not occluded (NEE) */
+        if (shadow.tfar >= 0.0f) {
+            // L += Lw * light_diffuse * ls.weight;
+            L += Lw * light_diffuse * ls.weight * dot(sample.Ng, ls.dir) / data.scene->lights.size();
+            // L += Lw * light_diffuse * ls.weight/ data.scene->lights.size();
+        }
+
+
+        Vec2f uv = sampler.get2D();
+        Sample3f wi;
+        Vec3fa diffuse = Material__sample(material_array, matId, brdf, Lw, wo, sample, wi, uv);
+
+        Lw *= diffuse / wi.pdf;
+
+        ray = Ray(sample.P,wi.v,EPS,inf);
+
     }
 
     return L;

Assignments/Assignment3/Application3.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "helper.hpp"
 #include "application_integrator.h"
+#include "simd/vboolf4_sse2.h"
 
 
 class Application3 : public ApplicationIntegrator {
@@ -10,10 +11,34 @@ public:
 
 private:
     Vec3fa renderPixel(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSamplerWrapper& sampler) override;
+    Vec3fa renderPixelPT(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSamplerWrapper& sampler);
+    Vec3fa renderPixelNEE(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSamplerWrapper& sampler);
 
 
     void drawGUI() override {
 		ApplicationIntegrator::drawGUI(); // NEW!
+        ImGui::InputInt("Ray depth", &ray_depth);
+        if (ray_depth < 1) {
+            ray_depth = 1;
+        }
+
+        const char* methods[] = {"PT", "NEE"};
+        if (ImGui::Combo("Methods", &method, methods, 2)) {
+            resetRender();
+        }
+        
+        const char* scenes[] = {"Cornell", "Ring"};
+        int oldscene = scene;
+        ImGui::Combo("Scenes", &scene, scenes, 2);
+        if (scene != oldscene) {
+            Data_Destructor(&data);
+            Data_Constructor(&data, 1, 8);
+            if (scene == 0)
+                standardScene();
+            if (scene == 1)
+                causticScene();
+        }
+        
     }
 
     void initScene() override;
@@ -23,4 +48,7 @@ private:
     void causticScene();
 
     float colorLight[3] = {1.0f, 1.0f, 1.0f};
+    int ray_depth = 5;
+    int scene = 0;
+    int method = 0;
 };