Footprint evaluation for volume rendering-英文文献.pdf

~ ComputerGraphics,Volume24, Number4, August 1990 Footprint Evaluation for Volume Rendering Lee Westover Numerical Design Limited The University of North Carolina at Chapel Hill ABSTRACT This distinction principly manifests itself in how and This paper presents a forward mapping rendering algo- when reconstruction of the three-dimensional signal is rithm to display regular volumetric grids that may not done. Convolution can be thought of as either generat- have the same spacings in the three grid directions. It ing an output sample from many input samples or as takes advantage of the fact that convolution can be spreading one input sample to many output samples. thought of as distributing energy from input samples into Backward mapping algorithms typically reconstruct the space. The renderer calculates an image plane footprint signal at a point in space by looking at that points for each data sample and uses the footprint to spread the nearest data samples and performing some type of inter- samples energy onto the image plane. A result of the polation. Forward mapping algorithms differ in that they technique is that the forward mapping algorithm can incrementally reconstruct the original signal by spread- support perspective without excessive cost, and support ing each data samples energy into space. adaptive resampling of the three-dimensional data se