Least Squares Vertex Baking

We investigate the representation of signals defined on triangle meshes using linearly interpolated vertex attributes. Compared to texture mapping, storing data only at vertices yields significantly lower memory overhead and less expensive runtime reconstruction. However, standard approaches to determine vertex values such as point sampling (a) or averaging triangle samples (b) lead to suboptimal approximations. We discuss how an optimal solution can be efficiently calculated using continuous least-squares (c); compare to ground truth per-pixel rendering (d). In addition, we propose a regularization term that allows us to minimize gradient discontinuities and mach banding artifacts while staying close to the optimum. Our method has been integrated in a game production lighting tool and we present examples of representing signals such as ambient occlusion and precomputed radiance transfer in real game scenes, where vertex baking was used to free up resources for other game components.

Ladislav Kavan, Adam W. Bargteil, Peter-Pike Sloan. Least Squares Vertex Baking. Computer Graphics Forum 30(4) [Proceedings of EGSR], 2011.  

We thank the anonymous reviewers for their feedback and helpful comments. Many thanks to Jeff Grills, Robert Kovach and Tony Bratton for help with integration in production tools and Peter Shirley for careful proofreading.