Added distant environment lighting.

main.cpp

@@ -35,6 +35,7 @@ static vec3 ** image;
 static void scene_1(vector<Figure *> & vf, vector<Light *> & vl, mat4x4 & i_model_view);
 static void scene_2(vector<Figure *> & vf, vector<Light *> & vl, mat4x4 & i_model_view);
 static void scene_3(vector<Figure *> & vf, vector<Light *> & vl, mat4x4 & i_model_view);
+static void scene_4(vector<Figure *> & vf, vector<Light *> & vl, mat4x4 & i_model_view);
 
 int main(int argc, char ** argv) {
   FILE * out;
@@ -363,3 +364,17 @@ static void scene_3(vector<Figure *> & vf, vector<Light *> & vl, mat4x4 & i_mode
 
   i_model_view = inverse(lookAt(eye, center, up));
 }
+
+static void scene_4(vector<Figure *> & vf, vector<Light *> & vl, mat4x4 & i_model_view) {
+  Sphere * s;
+  Plane * p;
+
+  s = new Sphere(0.0f, 0.0f, -2.0f, 1.0f);
+  s->m_mat.m_diffuse = vec3(1.0f, 1.0f, 0.0f);
+  vf.push_back(static_cast<Figure *>(s));
+
+  p = new Plane(vec3(0.0f, -1.0f, 0.0f), vec3(0.0f, 1.0f, 0.0f));
+  p->m_mat.m_diffuse = vec3(1.0f);
+  p->m_mat.m_specular = vec3(0.0f);
+  vf.push_back(static_cast<Figure *>(p));
+}

path_tracer.cpp

@@ -14,7 +14,7 @@ static const float PDF = (1.0f / (2.0f * pi<float>()));
 vec3 PathTracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Light *> & v_lights, unsigned int rec_level) const {
   float t, _t;
   Figure * _f;
-  vec3 n, color, i_pos, ref, sample, dir_diff_color, dir_spec_color, ind_color;
+  vec3 n, color, i_pos, ref, sample, dir_diff_color, dir_spec_color, ind_color, amb_color;
   Ray mv_r, sr, rr;
   bool vis;
   float kr, r1, r2;
@@ -53,8 +53,8 @@ vec3 PathTracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Light *
 	}
 
 	// Evaluate the shading model accounting for visibility.
-	dir_diff_color += (vis ? 1.0f : 0.0f) * v_lights[l]->diffuse(n, r, t, _f->m_mat);
+	dir_diff_color += vis ? v_lights[l]->diffuse(n, r, t, _f->m_mat) : vec3(0.0f);
-	dir_spec_color += (vis ? 1.0f : 0.0f) * v_lights[l]->specular(n, r, t, _f->m_mat);
+	dir_spec_color += vis ? v_lights[l]->specular(n, r, t, _f->m_mat) : vec3(0.0f);
       }
 
       // If enabled, calculate indirect lighting contribution.
@@ -67,7 +67,28 @@ vec3 PathTracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Light *
 	ind_color += r1 * trace_ray(rr, v_figures, v_lights, rec_level + 1) / PDF;
       }
 
-      color += ((dir_diff_color + ind_color) * (_f->m_mat.m_diffuse / pi<float>())) + dir_spec_color;
+      // Calculate environment light contribution
+      if (BCKG_COLOR.r > 0.0f || BCKG_COLOR.g > 0.0f || BCKG_COLOR.b > 0.0f) {
+	vis = true;
+
+	r1 = random01();
+	r2 = random01();
+	sample = sample_hemisphere(r1, r2);
+	rotate_sample(sample, n);
+	rr = Ray(normalize(sample), i_pos + (sample * BIAS));
+
+	// Cast a shadow ray to determine visibility.
+	for (size_t f = 0; f < v_figures.size(); f++) {
+	  if (v_figures[f]->intersect(rr, _t)) {
+	    vis = false;
+	    break;
+	  }
+	}
+
+	amb_color = vis ? BCKG_COLOR * max(dot(n, rr.m_direction), 0.0f) / PDF : vec3(0.0f);
+      }
+      
+      color += ((dir_diff_color + ind_color + amb_color) * (_f->m_mat.m_diffuse / pi<float>())) + dir_spec_color;
 
       // Determine the specular reflection color.
       if (_f->m_mat.m_rho > 0.0f && rec_level < MAX_RECURSION) {
@@ -100,5 +121,5 @@ vec3 PathTracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Light *
     return clamp(color, 0.0f, 1.0f);
 
   } else
-    return vec3(BCKG_COLOR);
+    return /*vec3(0.0f)*/ BCKG_COLOR;
 }

sphere.cpp

@@ -1,7 +1,6 @@
 #include "sphere.hpp"
 
-using glm::normalize;
+using namespace glm;
-using glm::sqrt;
 
 bool Sphere::intersect(Ray & r, float & t) const {
   float t1, t2;

tracer.cpp

@@ -6,7 +6,7 @@
 
 using namespace glm;
 
-const vec3 BCKG_COLOR = vec3(0.0f, 0.2f, 0.6f);
+const vec3 BCKG_COLOR = vec3(1.0f);
 
 float Tracer::random01() const {
   return static_cast<float>(rand()) / static_cast<float>(RAND_MAX);