MKSOURCE(1)						      General Commands Manual						       MKSOURCE(1)

NAME

       mksource - compute distant sources for RADIANCE image-based lighting

SYNOPSIS

       mksource [ -d nsamps ][ -t thresh ][ -a maxang ] [ octree ]

DESCRIPTION

       Mksource  produces a RADIANCE scene description of distant illum sources corresponding to bright, concentrated regions in the given ambient
       environment.  Any local geometry is ignored in the input octree, which should be derived from a captured light probe and modeled as a  dis-
       tant  hemispherical  or	spherical  glow source.  The output sources may then be combined with this environment to produce a more efficient
       scene for rendering, faster and less prone to sampling artifacts.

       The -d option may be used to specify the number of ray samples, which defaults to 262,000.  Calculation time  is  roughly  proportional	to
       this setting, and the default is fine enough to resolve sources the size of the sun (half a degree) or larger.

       The  -t	option may be used to manually set the radiance threshold for sources, in watts/sr/meter^2.  The default uses the top 2 percentile
       of the environment, which is usally a good value.

       The -a option may be used to specify a maximum source diameter, which defaults to 15 degrees.  Mkillum silently enforces a maximum  of  180
       degrees for this option.

       If no input octree is specified, the standard input is read.

EXAMPLE

       To add sources with a maximum size of 20 degrees to the enviornment described in environ.oct:

	 mksource -a 20 environ.oct > srcs.rad
	 oconv -i environ.oct srcs.rad > env+srcs.oct

AUTHOR

       Greg Ward

SEE ALSO

       mkillum(1), rpict(1), rvu(1)

RADIANCE
							     04/11/05							       MKSOURCE(1)