Efficient Screen Space Approach for Hardware Accelerated Surfel Rendering

At present, the best way to render textured pointsampled 3D objects is doubtless the use of elliptical weighted average (EWA) surface splatting. This technique provides a high quality rendering of complex point models with anisotropic texture filtering. In this paper we present a new multi-pass approach to perform EWA surface splatting on modern PC graphics hardware. The main advantage of our approach is to be bandwidth limited because we render only one vertex by sample. To achieve this goal we efficiently use the standard OpenGL point primitive. During the first pass, visibility splatting is performed by shifting surfel backward along the viewing rays and apply a parallax depth correction on each fragment. During the second rendering pass, screen space EWA filtering is computed for each vertex and performed for each fragment. Our algorithm is implemented using programmable vertex and fragment shaders of newer PC graphics hardware.