View-independent environment maps

Abstract

Environment maps are widely used for approximating reflections in hardware-accelerated rendering applications. Unfortunately, the parameterizations for environment maps used in today’s graphics hardware severely undersample certain directions, and can thus not be used from multiple viewing directions. Other parameterizations exist, but require operations that would be too expensive for hardware implementations. In this paper we introduce an inexpensive new parameterization for environment maps that allows us to reuse the environment map for any given viewing direction. We describe how, under certain restrictions, these maps can be used today in standard OpenGL implementations. Furthermore, we explore how OpenGL could be extended to support this kind of environment map more directly. CR Categories: 1.3.1 [Computer Graphics]: Hardware Architecture-Graphics processors; 1.3.3 [Computer Graphics]: Picture/Image Generation-Bitmap and framebuffer operations; 1.3.6 [Computer Graphics]: Methodology and Techniques--Standards 1.3.7 [Computer Graphics]: ThreeDimensional Graphics and Realism-Color, Shading, Shadowing and Texture 1.4.1 [Image Processing and Computer Vision]: Digitization and Image Capture ~-Sampling