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.\" RCSid "$Id: rtpict.1,v 1.9 2022/03/16 00:06:08 greg Exp $" |
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.TH RTPICT 1 3/19/2018 RADIANCE |
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.SH NAME |
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rtpict - generate a RADIANCE picture or layered image using rtrace |
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.SH SYNOPSIS |
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.B rtpict |
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.B "-n nproc" |
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[ |
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.B "-o[vrxlLRXnNsmM] out_dir" |
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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 "rpict options" |
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] |
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[ |
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.B @file |
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] |
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.B octree |
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.SH DESCRIPTION |
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.I Rtpict |
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is a script that generates a picture from the RADIANCE scene given in |
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.I octree |
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and sends it to the standard output, or to a file specified with the |
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.I \-o |
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option. |
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Most options and defaults are the same as |
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.I rpict(1), |
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although a few switches are silently ignored. |
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Options incompatible with multi-processing can generate an error. |
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.PP |
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The |
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.I rtrace(1) |
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tool is called with |
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.I vwrays(1) |
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to perform the actual work. |
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This enables the |
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.I \-n |
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option for multiprocessing on platforms that support it. |
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If the |
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.I \-n |
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option is not specified or is set to 1, then |
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.I rpict |
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is called directly. |
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There is no benefit in setting the number of processes to anything |
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greater than the number of virtual cores available on your machine. |
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Also, it is very important to set the |
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.I \-af |
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option if an irradiance cache is being generated; |
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otherwise, your speed-up will be far from linear. |
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.PP |
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If the |
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.I \-o |
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option has additional characters corresponding to output types from |
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.I rtrace, |
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it must be followed by the name of a directory that either exists or |
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will be created to contain image layers, one per output type. |
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The supported types are listed below, and do not include types that |
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are useless or have no convenient representation. |
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The table below shows the correspondence between output type and file name |
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in the specified directory: |
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.sp |
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.nf |
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v radiance.hdr |
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r r_refl.hdr |
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x r_unrefl.hdr |
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l d_effective.dpt |
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L d_firstsurf.dpt |
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R d_refl.dpt |
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X d_unrefl.dpt |
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n perturbed.nrm |
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N unperturbed.nrm |
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s surface.idx |
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m modifier.idx |
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M material.idx |
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.fi |
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.sp |
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Different encodings are associated with different data types. |
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Color data (from the 'v', 'r', and 'x' types) will be converted to |
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a flat RGBE picture by |
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.I pvalue(1). |
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Distances (from the 'l', 'L', 'R', and 'X' types) will be |
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converted to a 16-bit representation by |
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.I rcode_depth(1), |
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and the |
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.I \-d |
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option should be used to assign the reference (median) depth and world |
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units, which applies to the overall scene. |
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Surface normals (from the 'n' and 'N' types) will be converted |
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to a 32-bit representation by |
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.I rcode_normal(1). |
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Finally, identifiers (from the 's', 'm', and 'M' types) will be |
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converted to a 16-bit index format by |
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.I rcode_ident(1). |
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.PP |
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If the |
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.I \-i |
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option is used to turn on irradiane output, then the picture associated |
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with the 'v' type will be renamed |
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.I "irradiance.hdr" |
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and some other output types become irrelevant (i.e., 'r', 'x', 'R', and 'X'). |
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If one or more of the associated output files already exists in the |
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destination directory, an error will be printed and the command will abort. |
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.SH EXAMPLES |
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To render a scene with four processes: |
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.IP "" .2i |
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rtpict -n 4 -vf mypers.vf -ab 1 -af scene.amb scene.oct > scene_pers.hdr |
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.PP |
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To render radiance, first surface distance, and normals in a layered image: |
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.IP "" .2i |
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rtpict -n 8 -vf fish.vf @render.opt -ovLn fisholay scene.oct |
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.SH NOTES |
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Users should seriously consider using |
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.I rpiece(1) |
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for multiprocessing |
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when irradiance caching is employed with a shared ambient file. |
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If |
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.I rtpict |
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is used with |
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.I \-n |
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greater than 1, it tries to compute neighboring parts |
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of the same scanline in different processes, which can |
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result in many redundant calculations and cache entries. |
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.I Rtpict |
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will automatically run a randomly-ordered overture calculation |
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to mitigate this problem, but it is not a perfect solution. |
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.I Rpiece |
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avoids redundant cache calculations by working on separate tiles in each |
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process, which brings other benefits as well, such as enabling the |
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.I \-ps |
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option for image plane sampling. |
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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), mkpmap(1), oconv(1), pfilt(1), |
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pvalue(1), rad(1), rcode_depth(1), rcode_normal(1), rcode_ident(1), |
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rcrop(1), rpiece(1), rpict(1), rsplit(1), rtrace(1), rvu(1), vwrays(1) |
