Institute for Data Analysis and Visualization

Animation and visualization of rectilinear data require interpolation schemes for smooth image generation. Piecewise trilinear interpolation, the de facto standard for interpolating rectilinear data, usually leads to significant visual artifacts in the resulting imagery. These artifacts reduce the confidence in the resulting visualization, and may even lead to false interpretations of the data. This paper is concerned with the generation of smooth isosurface image sequences, obtained by casting rays through the image plane and computing their intersections with an isosurface. We describe a novel solution to this problem: We replace trilinear interpolation by tricubic interpolation, smoothing out the artifacts in the images; and we simplify the ray-isosurface intersection calculations by rotating and resampling the original rectilinear data in a second rectilinear grid -- a grid with one family of grid planes parallel to the image plane. Our solution significantly reduces artifacts in individual images and leads to smooth animations.