Pre-Integrated Volume Rendering for Multi-Dimensional Transfer Functions
Computer Graphics and Visualization Group, Technische Universität München, Germany
This work presents an efficient extension of pre-integrated volume rendering for multi-dimensional transfer functions. Since even two-dimensional transfer functions can result in strong rendering artifacts that cannot be resolved by standard ray casting, we propose a space-covering volume sampling scheme that does not require additional samples of the volume data. Based on this sampling scheme, our approach computes box integrals of the transfer functions, which are evaluated with the help of a small number of texture lookups in tabulated integral functions. We demonstrate the achieved performance and improvements in image quality with a prototypical GPU (graphics processing unit) implementation.