View-dependent multiresolutional flow texture advection

Abstract

Existing texture advection techniques will produce unsatisfactory rendering results when there is a discrepancy between the resolution of the flow field and that of the output image. This is because many existing texture advection techniques such as Line Integral Convolution (LIC) are inherently none view-dependent, that is, the resolution of the output textures depends only on the resolution of the input field, but not the resolution of the output image. When the resolution of the flow field after projection is much higher than the screen resolution, aliasing will happen unless the flow textures are appropriately filtered through some expensive post processing. On the other hand, when the resolution of the flow field is much lower than the screen resolution, a blocky or blurred appearance will be present in the rendering because the flow texture does not have enough samples. In this paper we present a view-dependent multiresolutional flow texture advection method for structured recti- and curvi-linear meshes. Our algorithm is based on a novel intermediate representation of the flow field, called trace slice, which allows us to compute the flow texture at a desired resolution interactively based on the run-time viewing parameters. As the user zooms in and out of the field, the resolution of the resulting flow texture will adapt automatically so that enough flow details will be presented while aliasing is avoided. Our implementation utilizes mipmapping and programmable GPUs available on modern programmable graphics hardware.