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.\" RCSid "$Id: rpiece.1,v 1.4 2018/03/20 02:40:38 greg Exp $" |
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.TH RXPIECE 1 6/4/2025 RADIANCE |
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.SH NAME |
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rxpiece - render tiles in a RADIANCE picture/depth buffer |
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.SH SYNOPSIS |
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.B rxpiece |
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[ |
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.B "\-n nproc" |
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][ |
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.B "\-x xres" |
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][ |
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.B "\-y yres" |
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][ |
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.B "\-X xdiv" |
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][ |
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.B "\-Y ydiv" |
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][ |
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.B "\-f{f|c}" |
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][ |
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.B "\-d ref_depth/unit" |
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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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rpict options |
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] |
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.B "\-o picture" |
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.B octree |
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.SH DESCRIPTION |
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.I Rxpiece |
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renders a RADIANCE picture a tile at a time. |
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This is useful for running multiple cooperating |
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processes to create a single picture. |
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Output is written to a memory-mapped file specified with the |
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.I \-o |
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argument. |
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The format will be determined by the |
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.I \-p |
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and |
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.I \-f |
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options. |
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The first is detailed in the |
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.I rpict(1) |
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man page, and the second may be |
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.I \-fc |
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for uncompressed common-exponent format or |
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.I \-ff |
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for float picture (matrix) output. |
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An output depth map may be given as well with the |
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.I \-z |
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option, which will be stored as raw float by default, |
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but can be written as a 16-bit/depth encoding if the |
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.I \-d |
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option is used to specify a reference depth/unit. |
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(See |
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.I rcode_depth(1).) |
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.PP |
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The overall picture dimensions will be |
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.I xres |
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by |
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.I yres |
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or smaller, depending on the |
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.I \-pa |
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option and other view options, and the picture will be rendered in |
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.I xdiv |
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by |
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.I ydiv |
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tiles. |
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.PP |
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If the output picture file already exists, new tiles will |
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be rendered into it. |
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In this way, multiple invocations of |
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.I rxpiece |
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may be used with or without the |
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.I \-n |
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multiprocessing option. |
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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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.SH EXAMPLE |
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Run 8 |
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.I rxpiece |
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processes and create an encoded depth map with a 10-meter reference: |
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.IP "" .2i |
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rxpiece -n 8 -d 10/meter -z scene.dpt -o scene.hdr scene.oct |
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.SH NOTES |
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Unfortunately, memory-mapped files are not supported across a |
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network, so |
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.I rxpiece |
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only works on a single machine. |
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If network rendering is desired, use |
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.I rpiece(1), |
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instead. |
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.PP |
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The main advantage of |
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.I rxpiece |
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over |
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.I rpiece |
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is the |
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.I \-n |
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multiprocessing option, which requires only a single invocation |
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to render a tiled picture efficiently. |
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.I Rxpiece |
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also supports more output types and options, such as float and |
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depth map results. |
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Because it avoids the need for a sync file, preferring a shared |
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memory map, tile assignment and recovery is faster and more robust |
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on a single machine. |
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.PP |
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The output picture is not run-length encoded, and can be quite |
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large. |
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Once the picture is finished, the |
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.I ra_rgbe(1) |
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program with the \-r option may be used to convert to a run\-length |
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encoded picture for more efficient storage, although |
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.I pfilt(1) |
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or any of the other Radiance picture filters will do the same |
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thing. |
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.PP |
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The ALRM signal may be used to gracefully terminate an |
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.I rxpiece |
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process after it finishes the tile it is working on. |
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This permits other currently running or subsequently started |
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.I rxpiece |
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process(es) to continue rendering tiles with no lost effort. |
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.SH AUTHOR |
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Greg Ward |
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.SH "SEE ALSO" |
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getinfo(1), pfilt(1), ra_rgbe(1), rcode_depth(1), rcomb(1), |
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rmtxop(1), rpict(1), rpiece(1), rtpict(1), ximage(1) |