Non-Pinhole Approximations for Interactive Rendering

Depth images have been used to approximate scene geometry in a variety of interactive 3-D graphics applications. In previous work, images were constructed using orthographic or perspective projection which limits approximation quality to what is visible along a single view direction or from a single viewpoint. This paper shows that images constructed with non-pinhole cameras improve approximation quality at little additional cost provided that the non-pinhole camera offers fast projection. For such a camera, the fundamental operation of ray depth-image intersection proceeds efficiently by searching along the onedimensional projection of the ray onto the image. In the context of two-camera configurations, our work extends epipolar geometry constraints to non-pinholes. We demonstrate the advantages of non-pinhole depth images in the context of reflections, refractions, relief texture mapping, and ambient occlusion.