Real-time Reflection and Refraction on a Per-vertex Basis

This paper proposes a novel method for real-time rendering of polygon mesh surfaces with reflection or refraction. The basic process is similar to dynamic environment mapping or cube mapping. Our proposed method is superior to those in that the accurate ray direction is reflected in the resulted image at every vertex on the mesh. Existing real-time techniques suffer from the differences between the viewpoint for the environment map and each reflection point. The proposed method minimizes this by finding an optimal viewpoint for the reflective or refractive mesh. With a sufficient number of vertices and map image resolutions, the users can render reflected images as accurate as ray tracing for all practical purposes, except for reflected objects around ray converging points of reflection on concave surfaces or refraction through convex lenses. The method can be applied to areas which require accuracy such as industrial design. Experiments with a CAD model of a car rear-view mirror and spectacle lenses exhibited results of sufficient quality for design verification.