Input data can be volume information (from MRI-scanners, computer tomographs) or geometric objects (CSG-, triangle data from CAD-systems) and is dragged along the pipeline. Every step depends on the result of the previous one. The visualization process takes as long as the sum of every single step.
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data acquisition | to import selected features. |
| data reduction | to reduce number of vertices, to reduce resolution. | |
| visibility transformation | coloring, transparency and hidden volume removal. | |
to select camera position, viewing direction. |
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to calculate a 2D-image. |
Fig.: Visualization Pipeline
The pipeline describes the necessary steps to generate an image from memory stored data.
We distinguish between volume data and geometric objects. Volume data are scanned density values, which give 3D-informations about the inside of a solid. Geometric objects are produced by the computer. A unique visualization pipeline must be traversed for each data type.
The pipeline has to be computed for every frame in order to visualize an interactive motion. The possible frame rate depends primarily on the data complexity.
