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.