Interactive reflections on curved objects

25th SIGGRAPH 1998 | , pp. 333-342

Global view-dependent illumination phenomena, in particular reflections, greatly enhance the realism of computer-generated imagery. Current interactive rendering methods do not provide satisfactory support for reflections on curved objects.
In this paper we present a novel method for interactive computation of reflections on curved objects. We transform potentially reflected scene objects according to reflectors, to generate virtual objects. These are rendered by the graphics system as ordinary objects, creating a reflection image that is blended with the primary image. Virtual objects are created by tessellating scene objects and computing a virtual vertex for each resulting scene vertex. Virtual vertices are computed using a novel space subdivision, the reflection subdivision. For general polygonal mesh reflectors, we present an associated approximate acceleration scheme, the explosion map. For specific types of objects (e.g., linear extrusions of planar curves) the reflection subdivision can be reduced to a 2-D one that is utilized more accurately and efficiently.