RSENSOR(1) General Commands Manual RSENSOR(1)
NAME
rsensor - compute sensor signal from a RADIANCE scene
SYNOPSIS
rsensor [ -n nprocs ][ -h ][ render options ] [ $EVAR ] [ @file ] { [ -rd nrays ][ -dn nsrc ][ sensor_view ] sensor_file .. } octree
rsensor [ -h ] { [ -rd nrays ][ sensor_view ] sensor_file .. } .
rsensor [ options ] -defaults
DESCRIPTION
Rsensor traces rays outward from one or more specified illumination sensors into the RADIANCE scene given by octree, sending the computed
sensor value to the standard output. (The octree may be given as the output of a command enclosed in quotes and preceded by a `!'.) In
the second form, a single period ('.') is given in place of an octree, and the origin and directions of the specified number of rays will
be printed on the standard output. If these rays are later traced and added together, the results will sum to a signal proportional to the
given sensor distribution. In the third form, the default values for the options (modified by those options present) are printed with a
brief explanation.
Options may be given on the command line and/or read from the environment and/or read from a file. A command argument beginning with a
dollar sign ('$') is immediately replaced by the contents of the given environment variable. A command argument beginning with an at sign
('@') is immediately replaced by the contents of the given file.
The sensor files themselves will be searched for in the path locations specified by the RAYPATH environment variable, similar to other
types of Radiance auxiliary files. If the sensor file path begins with '/', '.' or '~', no search will take place. Before each sensor
file, a separate view may be specified. In this case, the view origin and direction will correspond to the position and orientation of the
sensor, and the view up vector will determine the zero azimuthal direction of the sensor. The fore clipping distance may be used as well,
but other view options will be ignored. (See rpict(1) for details on how to specify a view.) The actual data contained in the sensor file
corresponds to the SPOT tab-separated matrix specification, where the column header has "degrees" in the leftmost column, followed by
evenly-spaced azimuthal angles. Each row begins with the polar angle, and is followed by the relative sensitivity values for each direc-
tion. A low-resolution example of a sensor file is given below:
degrees 0 90 180 270
0 .02 .04 .02 .04
45 .01 .02 .01 .02
90 .001 .002 .001 .002
As well as different views, the number of samples may be changed between sensors, where the -rd option controls the number of ray samples
sent at random, and the -dn option controls the number of rays sent to each light source per sensor.
The -h option toggles header output, which defaults to "on." The -n option may be used to specify multiple calculation processes on sys-
tems with more than one CPU. For additional options, consult the rtrace(1) man page. The final octree argument must be given, as the
octree cannot be read from the standard input.
EXAMPLES
To compute values for the same sensor with two different positions:
rsensor -ab 2 -vf posA.vf mysens.dat -vf posB.vf mysens.dat scene.oct
To generate a set of rays corresponding to a given sensor and compute the resulting signal with rtrace:
rsensor -h -vf posC.vf mysens.dat . | rtrace -h scene.oct | total -m
ENVIRONMENT
RAYPATH the directories to check for auxiliary files.
AUTHOR
Greg Ward for Architectural Energy Corporation
SEE ALSO
oconv(1), rpict(1), rtcontrib(1), rtrace(1)
RADIANCE
4/11/2008 RSENSOR(1)