Multi-mesh caching and hardware sampling for progressive and interactive rendering

Fournier, G., Péroche, B.

We present a framework for progressive and interactive rendering with soft shadows and indirect illumination of a triangulated scene. Our method is a multi-pass algorithm that separates the rendering of each main component of radiance in order to update the image as fast as new samples are computed. Those radiance samples are computed at the vertices of multiple recursively subdivided meshes, allowing fast hardware interpolation between the samples. These radiance samples are computed using irradiance values cached in multiple meshes. These meshes separate the direct irradiance from each light source and the indirect one. Using multiple meshes gives us the ability to better reuse samples and to better adapt the sampling density than if a unique mesh was used. We also propose to quickly compute accurate soft shadows and indirect irradiance using the graphics hardware for visibility determination.