Ubuntu Manpage: rsensor - compute sensor signal from a RADIANCE scene

Provided by: radiance_4R1+20120125-1.1_amd64

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 direction. 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 systems 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