filename     : p_Zwi02b.pdf
entry        : article
pages        : 223-238
year         : 2002
title        : EWA Splatting
author       : Matthias Zwicker and Hanspeter Pfister and Jeroen Van Baar and Markus Gross
booktitle    : IEEE Transactions on Computer Graphics and visualization
editor       :
publisher    : IEEE
language     : English
month        : July
keywords     : Rendering Systems, Volume Rendering, Texture Mapping, Splatting, Antialiasing
abstract     : In this paper, we present a framework for high quality splatting based on elliptical Gaussian kernels. To avoid aliasing artifacts, we introduce the concept of a resampling filter combining a reconstruction kernel with a low-pass filter. Because of the similarity to Heckbert's EWA (elliptical weighted average) filter for texture mapping, we call our technique EWA splatting. Our framework allows us to derive EWA splat primitives for volume data and for point-sampled surface data. It provides high image quality without aliasing artifacts or excessive blurring for volume data, and additionally features anisotropic texture filtering for point-sampled surfaces. It also handles non-spherical volume kernels efficiently, hence it is suitable for regular, rectilinear, and irregular volume datasets. Moreover, our framework introduces a novel approach to compute the footprint function, facilitating efficient perspective projection of arbitrary elliptical kernels at very little additional cost. Finally, we show that EWA volume reconstruction kernels can be reduced to surface reconstruction kernels. This makes our splat primitive universal in rendering surface and volume data.