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{ RCSid $Id$ } |
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{ |
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BAD fog simulation effect using a converted z-file, eg: |
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|
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pvalue -r -df -b -h `getinfo -d < scene.pic` scene.z | \ |
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pcomb -e VIS:20 -f fog.cal scene.pic - > foggy.pic |
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|
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The constant VIS must be set to the visibility distance, |
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ie. the distance at which half the contrast is lost. |
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|
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Substitute a local brightness model for fog_v to improve |
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the effect. |
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} |
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|
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dist = gi(2); { distance given by second file } |
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|
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fog_v : .5; { fog particles are uniform grey } |
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|
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prob = 1 - 2^-(dist/VIS); { probability of intercepting fog particle } |
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|
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fog(v) = prob*fog_v + (1-prob)*v; |
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|
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ro = fog(ri(1)); |
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go = fog(gi(1)); |
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bo = fog(bi(1)); |