Exact Projections onto the Hemisphere Inproceedings

Abstract:

Recent approaches to realistic image synthesis have split the rendering process into two passes. The first pass calculates an approximate global illumination solution, the second generates an image of high quality from a given view point using the illumination solution obtained in the first pass.
This paper discusses a new method for projecting polygons onto the hemisphere which is the central operation performed for each pixel during the local pass. The method calculates an exact hemispherical projection of all polygons considering occlusion. The chosen representation of the projected polygons facilitates the fast and accurate computation of formfactors with regard to the projection center.
The new hemispherical projection method is used to obtain an exact local pass solution.