.\" RCSid "$Id: compamb.1,v 1.3 2007/09/04 17:36:40 greg Exp $"

.TH COMPAMB 1 1/23/98 RADIANCE

.SH NAME

compamb - compute good ambient value for a rad input file

.SH SYNOPSIS

.B compamb

[

.B \-c

][

.B \-e

]

.B rad_input_file

.SH DESCRIPTION

.I Compamb

computes a good ambient value for the specified

.I rad(1)

variable file and appends it to the file as a "render= \-av" option.

If the

.I \-c

option is specified, then

.I compamb

includes color information in the computed ambient value, rather than

estimating a grey value to avoid rendering color shifts.

If the

.I \-e

option is specified, then

.I compamb

also computes a good exposure value for this scene, and appends it to

the

.I rad

file as well.

.PP

.I 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

.I compamb

calls

.I rpict(1)

to render low resolution frames for each view in the

.I 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

.I \-aw

option of

.I rpict,

which frequently results in splotchy artifacts.

.SH AUTHOR

Greg Ward Larson

.SH "SEE ALSO"

lookamb(1), rad(1), rpict(1)