Eigentransport for efficient and accurate all-frequency relighting

We present a method for creating a geometry-dependent basis for diffuse precomputed radiance transfer. Unlike previous PRT bases, ours is derived from Principal Component Analysis of the sampled transport functions at each vertex, without relying on pre-projections to secondary bases, such as the Spherical Harmonics or Haar wavelets. It allows for efficient evaluation of shading, has low memory requirements and produces accurate results with few coefficients. We are able to capture all-frequency effects from both distant and near-field dynamic lighting in real-time and present a simple and efficient rotation scheme. Reconstruction of the final shading becomes a low-order dot product and is performed on the GPU.