NAME
compamb - compute good ambient value for a rad input file
SYNOPSIS
compamb [ -c ][ -e ] rad_input_file
DESCRIPTION
Compamb computes a good ambient value for the specified rad(1) variable
file and appends it to the file as a "render= -av" option. If the -c
option is specified, then compamb includes color information in the
computed ambient value, rather than estimating a grey value to avoid
rendering color shifts. If the -e option is specified, then compamb
also computes a good exposure value for this scene, and appends it to
the rad file as well.
Compamb is a shell script that makes calls to other RADIANCE programs
and utilities to do the actual work. A substantial amount of time may
be required to complete this script, since compamb calls rpict(1) to
render low resolution frames for each view in the rad file, setting
"QUALITY=High" to compute interreflections. The resulting ambient file
is thrown away, since it would disagree with the new -av setting used
for the final renderings. This method is preferable to setting the -aw
option of rpict, which frequently results in splotchy artifacts.
AUTHOR
Greg Ward Larson
SEE ALSO
lookamb(1), rad(1), rpict(1)