new file mode 100644

Binary files /dev/null and b/doc/04_ray_resume.tga differ

@@ -19,6 +19,7 @@ using namespace glm;

 /// Constants

 auto const infinity = std::numeric_limits<float>::infinity();

+auto const delta    = 0.001F;

 /// Types

@@ -28,6 +29,15 @@ struct Ray

     vec3  origin;

     vec3  direction;

     float range;

+    vec3 point(float distance) const

+    {

+        return origin + direction * distance;

+    }

+    Ray resumed(float distance) const

+    {

+        distance += delta;

+        return {point(distance), direction, range - distance};

+    }

 };

 //// Trace

@@ -254,10 +264,16 @@ int main(int argc, char const * argv[])

     //// Render

     framebuffer.render(viewport, depth_range, [&](vec4 const & frag_coord)

     {

-        auto const ray   = camera.ray(frag_coord, depth_range);

-        auto const trace = scene.trace(ray);

-        auto const rgb   = vec3(1.0F / (1.0F + trace.distance));

-        auto const alpha = (bool)trace;

+        auto ray    = camera.ray(frag_coord, depth_range);

+        auto trace  = Trace{};

+        auto traces = 0;

+        while ((trace = scene.trace(ray)))

+        {

+            ++traces;

+            ray = ray.resumed(trace.distance);

+        }

+        auto const rgb   = vec3(1.0F / (1.0F + (float)traces));

+        auto const alpha = (bool)traces;

         return vec4(rgb, alpha);

     });

     //// Finalize