pathtracer adjustments

src/gui/manager.h

@@ -89,7 +89,7 @@ private:
     void frame(Scene &scene, Camera &cam);
 
     static inline const char *scene_file_types = "dae,obj,fbx,glb,gltf,3ds,blend,stl,ply";
-    static inline const char *image_file_types = "exr,jpg,jpeg,png,tga,bmp,psd,gif";
+    static inline const char *image_file_types = "exr,hdr,hdri,jpg,jpeg,png,tga,bmp,psd,gif";
 
     void render_selected(Scene_Object &obj);
     void load_scene(Scene &scene, Undo &undo, bool clear);

src/gui/widgets.cpp

@@ -635,7 +635,7 @@ std::string Widget_Render::step(Animate &animate, Scene &scene) {
                     return "Failed to write output!";
                 }
 
-                pathtracer.begin_render(scene, cam, true);
+                pathtracer.begin_render(scene, cam);
                 next_frame++;
             }
         }

src/rays/pathtracer.cpp

@@ -20,35 +20,6 @@ Pathtracer::Pathtracer(Gui::Widget_Render &gui, Vec2 screen_dim)
 
 Pathtracer::~Pathtracer() { thread_pool.stop(); }
 
-void Pathtracer::refit_scene(Scene &layout_scene) {
-
-    std::unordered_map<Scene_ID, Object> obj_map;
-    std::vector<Object> objs = scene.destructure();
-    for (auto &o : objs)
-        obj_map.insert({o.id(), std::move(o)});
-
-    std::set<Scene_ID> light_ids;
-    for (auto &l : lights)
-        light_ids.insert(l.id());
-
-    layout_scene.for_items([&](const Scene_Item &item) {
-        auto entry = obj_map.find(item.id());
-        if (entry != obj_map.end()) {
-            entry->second.set_trans(item.pose().transform());
-            if (light_ids.count(entry->first)) {
-                obj_map.erase(entry);
-            }
-        }
-    });
-
-    objs.clear();
-    for (auto &o : obj_map)
-        objs.push_back(std::move(o.second));
-
-    build_lights(layout_scene, objs);
-    scene.build(std::move(objs));
-}
-
 void Pathtracer::build_lights(Scene &layout_scene, std::vector<Object> &objs) {
 
     lights.clear();
@@ -160,7 +131,7 @@ void Pathtracer::build_scene(Scene &layout_scene) {
                     obj_list.push_back(
                         Object(std::move(shape), obj.id(), idx, obj.pose.transform()));
                 } else {
-                    Tri_Mesh mesh(obj.posed_mesh());
+                    Tri_Mesh mesh(obj.posed_mesh(), obj.get_mesh().flipped());
                     std::lock_guard<std::mutex> lock(obj_mut);
                     obj_list.push_back(
                         Object(std::move(mesh), obj.id(), idx, obj.pose.transform()));
@@ -236,7 +207,7 @@ size_t Pathtracer::visualize_bvh(GL::Lines &lines, GL::Lines &active, size_t dep
     return scene.visualize(lines, active, depth, Mat4::I);
 }
 
-void Pathtracer::begin_render(Scene &layout_scene, const Camera &cam, bool refit) {
+void Pathtracer::begin_render(Scene &layout_scene, const Camera &cam) {
 
     size_t n_threads = std::thread::hardware_concurrency();
     size_t samples_per_epoch = std::max(size_t(1), n_samples / (n_threads * 10));
@@ -247,10 +218,7 @@ void Pathtracer::begin_render(Scene &layout_scene, const Camera &cam, bool refit
     total_epochs = n_samples / samples_per_epoch + !!(n_samples % samples_per_epoch);
 
     build_time = SDL_GetPerformanceCounter();
-    if (refit)
-        refit_scene(layout_scene);
-    else
-        build_scene(layout_scene);
+    build_scene(layout_scene);
     render_time = SDL_GetPerformanceCounter();
     build_time = render_time - build_time;
 

src/rays/pathtracer.h

@@ -32,7 +32,7 @@ public:
     const GL::Tex2D &get_output_texture(float exposure);
     size_t visualize_bvh(GL::Lines &lines, GL::Lines &active, size_t level);
 
-    void begin_render(Scene &scene, const Camera &camera, bool refit = false);
+    void begin_render(Scene &scene, const Camera &camera);
     void cancel();
     bool in_progress() const;
     float progress() const;
@@ -41,7 +41,6 @@ public:
 private:
     // Internal
     void build_scene(Scene &scene);
-    void refit_scene(Scene &scene);
     void build_lights(Scene &scene, std::vector<Object> &objs);
     void do_trace(size_t samples);
     void accumulate(const HDR_Image &sample);

src/rays/tri_mesh.h

@@ -32,7 +32,7 @@ private:
 class Tri_Mesh {
 public:
     Tri_Mesh() = default;
-    Tri_Mesh(const GL::Mesh &mesh);
+    Tri_Mesh(const GL::Mesh &mesh, bool flip = false);
 
     BBox bbox() const;
     Trace hit(const Ray &ray) const;
@@ -44,6 +44,7 @@ public:
 private:
     std::vector<Tri_Mesh_Vert> verts;
     BVH<Triangle> triangles;
+    bool flip_normals = false;
 };
 
 } // namespace PT

src/student/shapes.cpp

@@ -25,6 +25,10 @@ Trace Sphere::hit(const Ray &ray) const {
     // but only the _later_ one is within ray.time_bounds, you should
     // return that one!
 
+    // Note: ray.dir is not necessarily a unit vector if this object has a scale transform.
+    // If you want it to be so, you should use ray.dir.unit(), and also note that you will
+    // have to re-scale ret.time to be the distance along the original non-unit ray.dir.
+
     Trace ret;
     ret.hit = false;       // was there an intersection?
     ret.time = 0.0f;       // at what time did the intersection occur?

src/student/tri_mesh.cpp

@@ -57,11 +57,15 @@ void Tri_Mesh::build(const GL::Mesh &mesh) {
     triangles.build(std::move(tris), 4);
 }
 
-Tri_Mesh::Tri_Mesh(const GL::Mesh &mesh) { build(mesh); }
+Tri_Mesh::Tri_Mesh(const GL::Mesh &mesh, bool flip) { build(mesh); flip_normals = flip; }
 
 BBox Tri_Mesh::bbox() const { return triangles.bbox(); }
 
-Trace Tri_Mesh::hit(const Ray &ray) const { return triangles.hit(ray); }
+Trace Tri_Mesh::hit(const Ray &ray) const { 
+    Trace t = triangles.hit(ray); 
+    if(flip_normals) t.normal = -t.normal;
+    return t;
+}
 
 size_t Tri_Mesh::visualize(GL::Lines &lines, GL::Lines &active, size_t level,
                            const Mat4 &trans) const {