Implementing the render cache and the edge-and-point image on graphics hardware

The render cache and the edge-and-point image (EPI) are alternative point-based rendering techniques that combine interactive performance with expensive, high quality shading for complex scenes. They use sparse sampling and intelligent reconstruction to enable fast framerates and to decouple shading from the display update.We present a hybrid CPU/GPU multi-pass system that accelerates these techniques by utilizing programmable graphics processing units (GPUs) to achieve better framerates while freeing the CPU for other uses such as high-quality shading (including global illumination). Because the render cache and EPI differ from the traditional graphics pipeline in interesting ways, we encountered several challenges in using the GPU effectively. We discuss our optimizations to achieve good performance, limitations with the current generation hardware, as well as possibilities for future improvements.