reflections

ssloy · Jan 20, 2019 · c80479d · cl0ne · Jan 27, 2019 · ssloy
1 parent ef70d13
commit c80479d
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Showing 2 changed files with 15 additions and 10 deletions.
diff --git a/out.jpg b/out.jpg
diff --git a/tinyraytracer.cpp b/tinyraytracer.cpp
@@ -12,9 +12,9 @@ struct Light {
 };
 
 struct Material {
-    Material(const Vec2f &a, const Vec3f &color, const float &spec) : albedo(a), diffuse_color(color), specular_exponent(spec) {}
-    Material() : albedo(1,0), diffuse_color(), specular_exponent() {}
-    Vec2f albedo;
+    Material(const Vec3f &a, const Vec3f &color, const float &spec) : albedo(a), diffuse_color(color), specular_exponent(spec) {}
+    Material() : albedo(1,0,0), diffuse_color(), specular_exponent() {}
+    Vec3f albedo;
     Vec3f diffuse_color;
     float specular_exponent;
 };
@@ -58,14 +58,18 @@ bool scene_intersect(const Vec3f &orig, const Vec3f &dir, const std::vector<Sphe
     return spheres_dist<1000;
 }
 
-Vec3f cast_ray(const Vec3f &orig, const Vec3f &dir, const std::vector<Sphere> &spheres, const std::vector<Light> &lights) {
+Vec3f cast_ray(const Vec3f &orig, const Vec3f &dir, const std::vector<Sphere> &spheres, const std::vector<Light> &lights, size_t depth=0) {
     Vec3f point, N;
     Material material;
 
-    if (!scene_intersect(orig, dir, spheres, point, N, material)) {
+    if (depth>4 || !scene_intersect(orig, dir, spheres, point, N, material)) {
         return Vec3f(0.2, 0.7, 0.8); // background color
     }
 
+    Vec3f reflect_dir = reflect(dir, N).normalize();
+    Vec3f reflect_orig = reflect_dir*N < 0 ? point - N*1e-3 : point + N*1e-3; // offset the original point to avoid occlusion by the object itself
+    Vec3f reflect_color = cast_ray(reflect_orig, reflect_dir, spheres, lights, depth + 1);
+
     float diffuse_light_intensity = 0, specular_light_intensity = 0;
     for (size_t i=0; i<lights.size(); i++) {
         Vec3f light_dir      = (lights[i].position - point).normalize();
@@ -80,7 +84,7 @@ Vec3f cast_ray(const Vec3f &orig, const Vec3f &dir, const std::vector<Sphere> &s
         diffuse_light_intensity  += lights[i].intensity * std::max(0.f, light_dir*N);
         specular_light_intensity += powf(std::max(0.f, -reflect(-light_dir, N)*dir), material.specular_exponent)*lights[i].intensity;
     }
-    return material.diffuse_color * diffuse_light_intensity * material.albedo[0] + Vec3f(1., 1., 1.)*specular_light_intensity * material.albedo[1];
+    return material.diffuse_color * diffuse_light_intensity * material.albedo[0] + Vec3f(1., 1., 1.)*specular_light_intensity * material.albedo[1] + reflect_color*material.albedo[2];
 }
 
 void render(const std::vector<Sphere> &spheres, const std::vector<Light> &lights) {
@@ -114,14 +118,15 @@ void render(const std::vector<Sphere> &spheres, const std::vector<Light> &lights
 }
 
 int main() {
-    Material      ivory(Vec2f(0.6,  0.3), Vec3f(0.4, 0.4, 0.3),   50.);
-    Material red_rubber(Vec2f(0.9,  0.1), Vec3f(0.3, 0.1, 0.1),   10.);
+    Material      ivory(Vec3f(0.6,  0.3, 0.1), Vec3f(0.4, 0.4, 0.3),   50.);
+    Material red_rubber(Vec3f(0.9,  0.1, 0.0), Vec3f(0.3, 0.1, 0.1),   10.);
+    Material     mirror(Vec3f(0.0, 10.0, 0.8), Vec3f(1.0, 1.0, 1.0), 1425.);
 
     std::vector<Sphere> spheres;
     spheres.push_back(Sphere(Vec3f(-3,    0,   -16), 2,      ivory));
-    spheres.push_back(Sphere(Vec3f(-1.0, -1.5, -12), 2, red_rubber));
+    spheres.push_back(Sphere(Vec3f(-1.0, -1.5, -12), 2,      mirror));
     spheres.push_back(Sphere(Vec3f( 1.5, -0.5, -18), 3, red_rubber));
-    spheres.push_back(Sphere(Vec3f( 7,    5,   -18), 4,      ivory));
+    spheres.push_back(Sphere(Vec3f( 7,    5,   -18), 4,     mirror));
 
     std::vector<Light>  lights;
     lights.push_back(Light(Vec3f(-20, 20,  20), 1.5));