Real-time geometric deformation displacement maps using programmable hardware

Abstract

Striving for photorealism, texture mapping, and its more advanced variations, bump and displacement mapping, have all become fundamental tools in computer graphics. Recently, the introduction of programmable graphics hardware has enabled the employment of displacement mapping in real-time applications. While displacement mapping facilitates the actual modification of the underlying geometry, it is constrained by being an injective mapping. Further, it is also limited because it usually maps the geometry of the (low-resolution) smooth base surfaces, typically by displacing their vertices. Drawing from recent work on deformation displacement mapping (DDM) [4], in this paper we offer real-time solutions to both these limitations. Our solutions make it possible to employ the DDM paradigm on programmable graphics hardware. By reversing the roles of the base surfaces and their geometric details, both the one-to-one constraint and the base surface resolution limitation are resolved. Furthermore, this role reversal also paves the way for other benefits such as a tremendous decrease in the memory consumption of geometric detail information in the DDM and the ability to animate the details over the base surface. We show that the presented scheme can be used effectively to generate highly complex renderings and animations, in real time, on modern graphics hardware. The capabilities of the proposed method are demonstrated for both rational parametric base surfaces and polygonal base surfaces.