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 distant
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)