Due to the current gap in continued funding from the U.S. National Science Foundation (NSF), the NSF Unidata Program Center has temporarily paused most operations. See NSF Unidata Pause in Most Operations for details.
Due to the current gap in continued funding from the U.S. National Science Foundation (NSF), the NSF Unidata Program Center has temporarily paused most operations. See NSF Unidata Pause in Most Operations for details.
Hi Bob, > Another question(s) about colors: > One of the parameters to the Gridded3DSet.makeIsoSurface() method looks > like an R,G,B tuple for each point in the gridded set. My question(s) is, > > 1) Where are these values computed? In other words, what class(es) is/are > responsible for this? and Values from various RealTypes are collected in doTransform() implementations in various subclasses of ShadowType, then these are assembled into R, G, B and A components in ShadowType.assembleColor(). This is pretty complex, because there can be any number of RealTypes mapped to Red, Green, Blue, Aalpha, RGB, RGBA, Cyan, Magenta, Yellow, CMY, Hue, Saturation, Value and HSV. Multiple RealTypes may be mapped to any one of the DisplayRealTypes. > 2> How are these values computed (conceptually)? Or perhaps another way > of asking would be, on what basis are these color values computed? > Is there a mapping from grid values to color values? and It all depends on which RealTypes are mapped to the color DisplayRealTypes listed above. > 3) Could the inverse computation be done? Could one write a function that > computed the original sample point from the color values (within some > margin of error)? Not in general, because multiple RealTypes can be mapped to DisplayRealTyoes (in which case they are added and this is not invertible). The various direct manipulation renderers (e.g., visad.java3d.DirectManipulationRendererJ3D) check on ScalarMaps and through Exceptions if spatial mappings are not invertible. It would be possible to write DataRenderer extensions that check to insure that color mappings are invertible, and then exploit it in some way. Cheers, Bill ---------------------------------------------------------- Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI 53706 hibbard@xxxxxxxxxxxxxxxxx 608-263-4427 fax: 608-263-6738 http://www.ssec.wisc.edu/~billh/vis.html
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