Fast Screen Space Curvature Estimation on GPU

Curvature is an important geometric property in computer graphics that provides information about the behavior of object surfaces. The exact curvature can only be calculated for a limited set of surfaces description. Most of the time, we deal with triangles, point sets or some other discrete representation of the surface. For those, curvature computation is problematic. Moreover, most of existing algorithms were developed for static geometry and can be slow for interactive modeling. This paper proposes a screen space method which estimates the mean and Gaussian curvature at interactive rates. The algorithm uses positions and normals to estimate the curvature from the second fundamental form matrix. Using the screen space has advantages over the classical approach: low-poly geometry can be used and additional detail can be added with normal and bump maps. The screen space curvature can be easily added to existing rendering pipelines. The proposed algorithm was tested on several models and it outperforms current state-of-the-art GPU approaches.