Front Buffer

The light propagation volume algorithm works in four different steps; reflective shadow map generation, light injection, light propagation and light rendering. In the first step, the scene is rendered into reflective shadow maps to get secondary light source information. With the light sources obtained in step one, we inject the lighting information into volume textures with spherical harmonics coefficients. The lighting information is then propagated and stored in a radiance volume; this step gives the algorithm its speed and visual fidelity. The final step is rendering the radiance volume to generate lighting information for the virtual scene.