The Normal Map Based on Area-Preserving Parameterization

TL;DR

This paper introduces a novel normal map rendering method based on area-preserving parameterization using semi-discrete Optimal Mass Transportation, which improves robustness and efficiency by avoiding surface cuts and chart packing.

Contribution

It presents a new normal map technique that preserves local area during surface unwrapping, eliminating the need for surface segmentation and chart packing.

Findings

More robust normal map rendering

Eliminates surface cutting and chart packing

Improves efficiency of normal map techniques

Abstract

In this paper, we present an approach to enhance and improve the current normal map rendering technique. Our algorithm is based on semi-discrete Optimal Mass Transportation (OMT) theory and has a solid theoretical base. The key difference from previous normal map method is that we preserve the local area when we unwrap a disk-like 3D surface onto 2D plane. Compared to the currently used techniques which is based on conformal parameterization, our method does not need to cut a surface into many small pieces to avoid the large area distortion. The following charts packing step is also unnecessary in our framework. Our method is practical and makes the normal map technique more robust and efficient.