assignment 4 part 2

.gitignore

@@ -1,4 +1,5 @@
 /build
+/build_debug
 .DS_Store
 /nori
 /warptest

include/nori/accel.h

@@ -35,6 +35,8 @@ NORI_NAMESPACE_BEGIN
  */
 class Accel {
 public:
+    Accel(std::vector<Mesh*> *ms) : m_meshes(ms) {}
+
     /**
      * \brief Register a triangle mesh for inclusion in the acceleration
      * data structure
@@ -82,7 +84,8 @@ class Accel {
     bool rayIntersect(const Ray3f &ray, Intersection &its, bool shadowRay) const;
 
 private:
-    Mesh         *m_mesh = nullptr; ///< Mesh (only a single one for now)
+    //Mesh         *m_mesh = nullptr; ///< Mesh (only a single one for now)
+    std::vector<Mesh*> *m_meshes = nullptr;
     BoundingBox3f m_bbox;           ///< Bounding box of the entire scene
 
 #ifdef USE_OCTREE_ACCEL

include/nori/emitter.h

@@ -36,9 +36,10 @@ struct EmitterQueryRecord {
         : ref(r)
     {}
 
-    EmitterQueryRecord(const Point3f &r, const Point3f &p)
+    EmitterQueryRecord(const Point3f &r, const Point3f &p, const Normal3f &n)
         : ref(r)
         , pos(p)
+        , n(n)
     {
         wi = (pos - ref).normalized();
     }

include/nori/scene.h

@@ -58,6 +58,9 @@ class Scene : public NoriObject {
     /// Return a reference to an array containing all meshes
     const std::vector<Mesh *> &getMeshes() const { return m_meshes; }
 
+    /// Return a reference to an array of emitters
+    std::vector<Emitter *> &getEmitters() { return m_emitters; }
+
     /// Return a random light
     const Emitter *getRandomEmitter(const float &xi, float &pdf) const;
 

src/accel.cpp

@@ -26,10 +26,12 @@
 NORI_NAMESPACE_BEGIN
 
 void Accel::addMesh(Mesh *mesh) {
+    /*
     if (m_mesh)
         throw NoriException("Accel: only a single mesh is supported!");
     m_mesh = mesh;
     m_bbox = m_mesh->getBoundingBox();
+    */
 }
 
 #ifdef USE_OCTREE_ACCEL
@@ -78,6 +80,7 @@ void Accel::build() {
     rtcSetSceneFlags(m_scene, RTC_SCENE_FLAG_ROBUST);
     rtcSetSceneBuildQuality(m_scene, RTC_BUILD_QUALITY_HIGH);
 
+    /*
     RTCGeometry geom = rtcNewGeometry(m_device, RTC_GEOMETRY_TYPE_TRIANGLE);
     rtcSetSharedGeometryBuffer(geom, RTC_BUFFER_TYPE_VERTEX, 0,
         RTC_FORMAT_FLOAT3, m_mesh->getVertexPositionsPtr(), 0, sizeof(float) * 3,
@@ -88,6 +91,20 @@ void Accel::build() {
     rtcCommitGeometry(geom);
     rtcAttachGeometryByID(m_scene, geom, 0); // ID 0 since we only have one mesh now
     rtcReleaseGeometry(geom);
+    */
+
+    for (size_t i = 0; const auto mesh_ptr : *m_meshes) {
+        RTCGeometry geom = rtcNewGeometry(m_device, RTC_GEOMETRY_TYPE_TRIANGLE);
+        rtcSetSharedGeometryBuffer(geom, RTC_BUFFER_TYPE_VERTEX, 0,
+            RTC_FORMAT_FLOAT3, mesh_ptr->getVertexPositionsPtr(), 0, sizeof(float) * 3,
+            mesh_ptr->getVertexCount());
+        rtcSetSharedGeometryBuffer(geom, RTC_BUFFER_TYPE_INDEX, 0,
+            RTC_FORMAT_UINT3, mesh_ptr->getIndicesPtr(), 0, sizeof(uint32_t) * 3,
+            mesh_ptr->getTriangleCount());
+        rtcCommitGeometry(geom);
+        rtcAttachGeometryByID(m_scene, geom, i++);
+        rtcReleaseGeometry(geom);
+    }
 
     rtcCommitScene(m_scene);
 
@@ -154,7 +171,8 @@ bool Accel::rayIntersect(const Ray3f &ray_, Intersection &its, bool shadowRay) c
 
         its.t = rayhit.ray.tfar;
         its.uv = Point2f(rayhit.hit.u, rayhit.hit.v);
-        its.mesh = m_mesh;
+        //its.mesh = m_mesh;
+        its.mesh = m_meshes->at(rayhit.hit.geomID);
         f = rayhit.hit.primID;
         foundIntersection = true;
     }

src/area.cpp

@@ -38,6 +38,11 @@ void AreaLight::setParent(NoriObject *parent) {
 Color3f AreaLight::sample(Sampler *sampler, EmitterQueryRecord &erec, float &pdf) const {
     m_mesh->sample(sampler, erec.pos, erec.n, pdf);
     erec.wi = (erec.pos - erec.ref).normalized();
+    float cosTheta = erec.n.dot(-erec.wi);
+    if (cosTheta > 0.f) {
+        auto distance2 = (erec.pos - erec.ref).squaredNorm();
+        pdf = pdf * distance2 / cosTheta;
+    }
 
     if (pdf > 0.f)
         return eval(erec) / pdf;

src/mesh.cpp

@@ -24,6 +24,7 @@
 #include <nori/bbox.h>
 #include <nori/bsdf.h>
 #include <nori/emitter.h>
+#include <nori/scene.h>
 #include <nori/warp.h>
 #include <Eigen/Geometry>
 #include <tbb/parallel_for.h>

src/scene.cpp

@@ -26,7 +26,8 @@
 NORI_NAMESPACE_BEGIN
 
 Scene::Scene(const PropertyList &) {
-    m_accel = new Accel();
+    //m_accel = new Accel();
+    m_accel = new Accel(&m_meshes);
 }
 
 Scene::~Scene() {
@@ -60,6 +61,11 @@ void Scene::activate() {
             NoriObjectFactory::createInstance("independent", PropertyList()));
     }
 
+    for (const auto mesh : m_meshes) {
+        if (mesh->isEmitter())
+            m_emitters.push_back(mesh->getEmitter());
+    }
+
     cout << endl;
     cout << "Configuration: " << toString() << endl;
     cout << endl;
@@ -69,14 +75,15 @@ void Scene::addChild(NoriObject *obj) {
     switch (obj->getClassType()) {
         case EMesh: {
                 Mesh *mesh = static_cast<Mesh *>(obj);
-                m_accel->addMesh(mesh);
+                //m_accel->addMesh(mesh);
                 m_meshes.push_back(mesh);
             }
             break;
 
         case EEmitter: {
-                Emitter *emitter = static_cast<Emitter *>(obj);
-                m_emitters.push_back(emitter);
+                //Emitter *emitter = static_cast<Emitter *>(obj);
+                /* TBD */
+                throw NoriException("Scene::addChild(): You need to implement this for emitters");
             }
             break;
 

src/whitted.cpp

@@ -18,7 +18,7 @@ class WhittedIntegrator : public Integrator {
         // Calculate Le if primary ray hit emitter
         Color3f Le(0.f);
         if (its.mesh->isEmitter()) {
-            EmitterQueryRecord erec(ray.o, its.p);
+            EmitterQueryRecord erec(ray.o, its.p, its.shFrame.n);
             Le = its.mesh->getEmitter()->eval(erec);
         }
 
@@ -29,18 +29,19 @@ class WhittedIntegrator : public Integrator {
         float lpdf;
         auto Ls = emitter->sample(sampler, erec, lpdf);
 
-        Ray3f shadow_ray;
-        shadow_ray.o = its.p;
-        auto light_dir = (erec.pos - its.p).normalized();
-        shadow_ray.d = light_dir;
+        auto light_vec = (erec.pos - its.p);
+        auto light_dir = light_vec.normalized();
+        Ray3f shadow_ray(its.p, light_dir, Epsilon, light_vec.norm() - Epsilon);
         if (scene->rayIntersect(shadow_ray))
             return Le;
 
         auto bsdf = its.mesh->getBSDF();
-        BSDFQueryRecord brec(light_dir);
-        auto f = bsdf->eval(brec);
+        BSDFQueryRecord brec(its.toLocal(-ray.d), its.toLocal(erec.wi), ESolidAngle);
+        Color3f f = bsdf->eval(brec);
         auto cosTheta = Frame::cosTheta(its.shFrame.toLocal(light_dir));
-        auto Li = f * Ls * cosTheta / pdf;
+        if (cosTheta < 0.f)
+            cosTheta = 0.f;
+        Color3f Li = f * Ls * cosTheta / pdf;
 
         return Le + Li;
     }

tests/integrator/normal_integrator.cpp

@@ -8,7 +8,7 @@
 using namespace nori;
 
 int main() {
-    filesystem::path path("../scenes/pa2/ajax-normals.xml");
+    filesystem::path path("../scenes/pa4/cbox/cbox-distributed.xml");
 
     try {
         getFileResolver()->prepend(path.parent_path());
@@ -24,7 +24,7 @@ int main() {
     if (root->getClassType() == NoriObject::EScene) {
         auto scene = static_cast<Scene*>(root.get());
         std::unique_ptr<Sampler> sampler(scene->getSampler()->clone());
-        Point2f pixelSample = Point2f(250.f, 698.f) + sampler->next2D();
+        Point2f pixelSample = Point2f(400.f, 60.f) + sampler->next2D();
         Point2f apertureSample = sampler->next2D();
 
         Ray3f ray;