Local irradiance estimation for use in rendering an image

摘要

Relightable free-viewpoint rendering allows a novel view of a scene to be rendered and relit based on multiple views of the scene from multiple camera viewpoints. Cast shadows in the scene are handled to allow local occlusion to be taken into account when determining irradiance estimates for the sample positions in the scene. This is achieved by determining an initial estimate of irradiance by ignoring local occlusion, then using that initial irradiance estimate with knowledge of the scene geometry to determine an angle-dependent radiance estimate for the scene. This radiance estimate can then be used with the knowledge of the scene geometry to determine local irradiance estimates at the sample positions within the scene.

主权项

1. A method of determining local irradiance estimates for a scene in an image processing system, the method comprising:
obtaining initial irradiance estimates for sample positions on one or more surfaces in the scene, the initial irradiance estimates being based on a global irradiance estimate for the scene; obtaining visibility indications which indicate the visibility of the sample positions in the scene in dependence on viewing angle; calculating an angle-dependent radiance estimate for the scene using the obtained initial irradiance estimates and the obtained visibility indications; and determining local irradiance estimates at the sample positions using the radiance estimate and the visibility indications.