Robust Diffuse Final Gathering on the GPU Tamás Umenhoffer, László Szirmay-Kalos Department of Control Engineering and Information Technology, Budapest University of Technology, Hungary

Indirect Illumination

Angle between illumination direction and surface normals Rendering Equation Angle between illumination direction and surface normals at x and y Incoming radiance to x Visibility indicator between x and y

Ray Casting illuminating points eye pixel sample point

Environment Mapping radiance, distance

Virtual area light sources Virtual lights group lights Area lights

Cubemap downsample 256 x 256 x 6 4 x 4 x 6 Average radiance and distance values Downsample 4 x 4 x 6 one pixel – one area light

Point to point form factor

Polygon to point form factor

Polygon to point form factor tangent plane + + -

Results Point to point Polygon to point

Classic Point to point Polygon to point Mental Ray 600 FPS 60 FPS 11 FPS 30 sec

Results

Results

Conclusion Robust diffuse final gathering Cube map GPU Interactive / real-time

Thank you for your attention!