GI using Reflective Shadow Maps


  • Implemented a custom GI lighting engine on top of the Unity 5 lighting engine by using the image obtained from the direct lighting phase of Unity 5 and adding GI to it.
  • Generated the first bounce reflective shadow map from the perspective view of the spotlight, calculated an average position and normal from the first bounce VPLs to orient the second bounce camera in the average normal direction and placing it in the average VPL position to obtain an approximate secound bounce diffuse lighting.
  • Obtained a final image with indirect diffuse illumination by additively blending together the 3 textures : direct lighting, first bounce indirect diffuse and second bounce indirect diffuse.
  • Two major problems associated with RSM : (1) No sharp reflections as the surfaces are assumed to be perfectly diffuse, and (2) No occlusion of light coming from VPLs is computed.
  • Simulated local reflections using SSR and approximated occlusion using SSAO.


July, 2016