Programmable shading is a common technique for production animation, but interactive programmable shading is not yet widely available. We support interactive programmable shading on virtually any 3D graphics hardware using a scene graph library on top of OpenGL. We treat the OpenGL architecture as a general SIMD computer, and translate the high-level shading description into OpenGL rendering passes. While our system uses OpenGL, the techniques described are applicable to any retained mode interface with appropriate extension mechanisms and hardware API with provisions for recirculating data through the graphics pipeline.

We present a bumpmappingmethod that requires minimal hardware beyond that necessary for Phong shading. We eliminate the costly per-pixel steps of reconstructing a tangent space and perturbing the interpolated normal vector by a) interpolating vectors that havebeen transformed into tangent space at polygon vertices and b) storing a precomputed, perturbed normal map as a texture. This represents a considerable savings in hardware or rendering speed compared to a straightforward implementation of bump mapping. CR categories and subject descriptors: I.3.3 [Computer Graphics]: Picture/Image generation

We present a general linear transform method for handling full spectral information in computer graphics rendering.In this framework, any spectral power distribution in a scene is described with respect to a set of fixed orthonormal basis functions.The lighting computations follow simply from this decision, and they can be viewed as a generalization of point sampling.Because any basis functions can be chosen, they can be tailored to the scenes that are to be rendered.We discuss efficient point sampling for scenes with smoothly varying spectra, and we present the use of characteristic vector analysis to select sets of basis functions that deal efficiently with irregular spectral power distributions.As an example of this latter method, we render a scene illuminated with fluorescent light.

New display technologies have begun to provide more innovative and potentially powerful methods to present information to a viewer. However, many of these techniques struggle to deliver accurate full color. In this paper, we address this difficulty by employing the dichromatic theory of color reflection, which implies that many objects can be rendered accurately using only two primaries. Complex display systems with two primaries can be produced with significantly less work than is required for the traditional three primaries. We discuss methods for selecting objects that can be rendered accurately on two-color displays, and we present our experiments with a two-color display using monochromatic primaries.>