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.\" RCSid "$Id: rsensor.1,v 1.4 2010/09/26 15:41:46 greg Exp $" |
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.TH RSENSOR 1 4/11/2008 RADIANCE |
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.SH NAME |
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rsensor - compute sensor signal from a RADIANCE scene |
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.SH SYNOPSIS |
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.B rsensor |
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[ |
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.B -n nprocs |
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][ |
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.B -h |
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][ |
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.B render options |
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] |
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[ |
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.B $EVAR |
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] |
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[ |
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.B @file |
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] |
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{ |
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[ |
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.B -rd nrays |
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][ |
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.B -dn nsrc |
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][ |
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.B sensor_view |
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] |
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.B sensor_file .. |
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} |
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.B octree |
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.br |
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.B rsensor |
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[ |
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.B -h |
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] |
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{ |
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[ |
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.B -rd nrays |
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][ |
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.B sensor_view |
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] |
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.B sensor_file .. |
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} |
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.B "." |
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.br |
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.B "rsensor [ options ] \-defaults" |
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.SH DESCRIPTION |
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.I Rsensor |
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traces rays outward from one or more specified illumination |
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sensors into the RADIANCE scene given by |
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.I octree, |
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sending the computed sensor value to the standard output. |
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(The octree may be given as the output of a command enclosed in quotes |
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and preceded by a `!'.)\0 |
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In the second form, a single period ('.') is given in place of an |
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octree, and the origin and directions of the specified |
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number of rays will be printed on the standard output. |
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If these rays are later traced and added together, the results |
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will sum to a signal proportional to the given sensor distribution. |
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In the third form, the default values |
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for the options (modified by those options present) |
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are printed with a brief explanation. |
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.PP |
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Options may be given on the command line and/or read from the |
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environment and/or read from a file. |
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A command argument beginning with a dollar sign ('$') is immediately |
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replaced by the contents of the given environment variable. |
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A command argument beginning with an at sign ('@') is immediately |
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replaced by the contents of the given file. |
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.PP |
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The sensor files themselves will be searched for in the path |
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locations specified by the |
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.I RAYPATH |
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environment variable, similar to other types of Radiance |
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auxiliary files. |
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If the sensor file path begins with '/', '.' or '~', no search |
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will take place. |
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Before each sensor file, a separate view may be specified. |
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In this case, the view origin and direction will correspond to |
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the position and orientation of the sensor, and the view up |
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vector will determine the zero azimuthal direction of the sensor. |
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The fore clipping distance may be used as well, but other view |
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options will be ignored. |
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(See |
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.I rpict(1) |
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for details on how to specify a view.)\0 |
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The actual data contained in the sensor file corresponds to the |
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.I SPOT |
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tab-separated matrix specification, where the |
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column header has "degrees" in the leftmost column, followed |
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by evenly-spaced azimuthal angles. |
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Each row begins with the polar angle, and is followed by the |
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relative sensitivity values for each direction. |
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A low-resolution example of a sensor file is given below: |
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.sp |
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.nf |
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degrees 0 90 180 270 |
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0 .02 .04 .02 .04 |
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45 .01 .02 .01 .02 |
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90 .001 .002 .001 .002 |
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.fi |
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.sp |
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As well as different views, the number of samples may be changed between |
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sensors, where the |
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.I \-rd |
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option controls the number of ray samples sent at random, and the |
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.I \-dn |
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option controls the number of rays sent to each light source per sensor. |
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.PP |
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The |
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.I \-h |
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option toggles header output, which defaults to "on." |
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The |
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.I \-n |
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option may be used to specify multiple calculation processes on |
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systems with more than one CPU. |
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For additional options, consult the |
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.I rtrace(1) |
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man page. |
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The final |
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.I octree |
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argument must be given, as the octree cannot be read from the |
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standard input. |
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.SH EXAMPLES |
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To compute values for the same sensor with two different positions: |
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.IP "" .2i |
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rsensor -ab 2 -vf posA.vf mysens.dat -vf posB.vf mysens.dat scene.oct |
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.PP |
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To generate a set of rays corresponding to a given sensor and compute |
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the resulting signal with rtrace: |
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.IP "" .2i |
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rsensor -h -vf posC.vf mysens.dat . | rtrace -h scene.oct | total -m |
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.SH ENVIRONMENT |
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RAYPATH the directories to check for auxiliary files. |
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.SH AUTHOR |
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Greg Ward for Architectural Energy Corporation |
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.SH "SEE ALSO" |
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oconv(1), rpict(1), rcontrib(1), rtrace(1) |