Browsing by Author "KE, HR"

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RAY-CAST VOLUME RENDERING ACCELERATED BY INCREMENTAL TRILINEAR INTERPOLATION AND CELL TEMPLATES
(1995)
KE, HR
;
CHANG, RC
;
資訊工程學系
;
Department of Computer Science
Two related ideas for improving the speed of ray-cast volume rendering are studied in this paper. The first is an incremental algorithm for trilinear interpolation, a method commonly used in ray-cast volume rendering to calculate sample values. The incremental algorithm can expedite trilinear interpolation when many samples along a ray are located in one cell. The second is an efficient hybrid volume rendering restricted to parallel projection. In the preprocessing stage, a cell template is created to store the information used by the incremental trilinear interpolation. When a cell is parallel projected, the information is retrieved from the template to compute the cell contribution. Because the algorithm with only one template may cause aliasing, an antialiasing technique exploiting multiple cell templates is proposed. With our method, ray-cast volume rendering can be accelerated considerably.
SAMPLE BUFFER - A PROGRESSIVE REFINEMENT RAY-CASTING ALGORITHM FOR VOLUME RENDERING
(1993-05-01)
KE, HR
;
CHANG, RC
;
資訊工程學系
;
Department of Computer Science
Ray-casting has been shown to be an excellent technique for rendering volume data. This paper describes a new ray-casting algorithm that employs the concept of progressive refinement for volume rendering. Volume data are embedded into a complete octree, and when the volume data are rendered, the octree is traversed according to a user-defined threshold. By reducing this threshold gradually, we can render increasingly refined images. Ray-casting is used to explore the octree, and a data structure called a sample buffer (SB) is introduced to reduce the time required to render a series of images. With this method, a satisfactory balance between image quality and computation time can be achieved.