Real time area light approximation (friendly for current gen gpus)

Design and implementation of a new lighting model in order to approximate area light source in real time.
This work has been done as a contractor for a 3d real time architectural previsualization.
The technical environment is DX11 and the task schedule is one month and a half for full integration into the existing shading framework and implementation of both diffuse and shadow contribution.

• Principal diffuse component attenuation uses a form factor approximation dependent on solid angle is not really costly (only a few cross and dots).

• Soft shadows are done using nvidia's PCSS algorithm enhanced to not exhibit imprecision problems inherent to filtering especially on edges in light space and cubemap faces border of the shadow map.This part can be problematic on low fillrate gpu's since it necessitate a high number of samples to look correct. I used DX11 sample compare functionnality (hardware shadows) to mitigate this.

complex material scene interaction

urban metro diffuse component only

in this scene the light area is covering a large area and would be a great input to any real time GI algorithm.

soft shadows