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.\" RCSid "$Id: mksource.1,v 1.5 2007/09/04 17:36:40 greg Exp $" |
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.TH MKSOURCE 1 04/11/05 RADIANCE |
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.SH NAME |
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mksource - compute distant sources for RADIANCE image-based lighting |
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.SH SYNOPSIS |
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.B mksource |
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[ |
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.B "\-d nsamps" |
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][ |
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.B "\-t thresh" |
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][ |
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.B "\-a maxang" |
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] |
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[ |
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.B octree |
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] |
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.SH DESCRIPTION |
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.I Mksource |
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produces a RADIANCE scene description of distant illum |
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sources corresponding to bright, concentrated regions in |
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the given ambient environment. |
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Any local geometry is ignored in the input octree, which |
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should be derived from a captured light probe and modeled |
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as a distant hemispherical or spherical glow source. |
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The output sources may then be combined with this environment |
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to produce a more efficient scene for rendering, faster and |
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less prone to sampling artifacts. |
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.PP |
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The |
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.I \-d |
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option may be used to specify the number of ray samples, which |
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defaults to 262,000. |
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Calculation time is roughly proportional to this setting, and the |
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default is fine enough to resolve sources the size of the sun |
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(half a degree) or larger. |
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.PP |
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The |
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.I \-t |
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option may be used to manually set the radiance threshold for |
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sources, in watts/sr/meter^2. |
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The default uses the top 2 percentile of the environment, which |
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is usally a good value. |
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.PP |
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The |
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.I \-a |
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option may be used to specify a maximum source diameter, |
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which defaults to 15 degrees. |
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.I Mkillum |
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silently enforces a maximum of 180 degrees for this option. |
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.PP |
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If no input octree is specified, the standard input is read. |
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.SH EXAMPLE |
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To add sources with a maximum size of 20 degrees |
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to the environment described in environ.oct: |
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.IP "" .2i |
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mksource \-a 20 environ.oct > srcs.rad |
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.br |
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oconv \-i environ.oct srcs.rad > env+srcs.oct |
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.SH AUTHOR |
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Greg Ward |
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.SH "SEE ALSO" |
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mkillum(1), rpict(1), rvu(1) |
