Enhanced Billboards for Model Simplification

Abstract

A set of billboards can represent 3D models for extreme simplification in real-time rendering. Unlike conventional polygon method, billboard-based technique has the rendering time of the model proportional to its contribution to the image. Thus, it has an automatically built-in Level of Detail. However, previous techniques still have limited viewing angle and do not accurately represent the model. We present an adaptive rendering method using enhanced billboards. First, each enhanced billboard, representing portion of the model, is defined to have four maps: depth map, normal map, color map and transparency map. The model is then projected onto a number of viewing planes in different viewing directions. Consequently, these enhanced billboards are rendered based on ray-height-field intersection algorithm implemented on GPU. This representation can maintain the geometry and the silhouette of the model with no limit in viewing direction. Moreover, real-time rendering is supported.