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.\" RCSid "$Id: pmapdump.1,v 1.6 2015/01/13 17:29:13 taschreg Exp taschreg $" |
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.TH PMAPDUMP 1 "$Date: 2015/01/13 17:29:13 $ $Revision: 1.6 $" RADIANCE |
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|
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.SH NAME |
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pmapdump - generate RADIANCE scene description of photon map distribution |
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|
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.SH SYNOPSIS |
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pmapdump [\fB-n\fR \fInspheres1\fR] [\fB-r\fR \fIradscale1\fR] \fIpmap1\fR |
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[\fB-n\fR \fInspheres2\fR] [\fB-r\fR \fIradscale2\fR] \fIpmap2\fR ... |
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|
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.SH DESCRIPTION |
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\fIpmapdump\fR takes one or more photon map files generated with |
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\fImkpmap(1)\fR as input and sends a RADIANCE scene description of their |
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photon distributions to the standard output. This can be visualised with |
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e.g. \fIobjview(1)\fR, \fIrpict(1)\fR, or \fIrvu(1)\fR to assess the |
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location and local density of photons in relation to the scene geometry. |
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.PP |
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An arbitrary number of photon maps can be specified on the command line and |
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the respective photon type is determined automagically. The different |
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photon types are visualised as colour coded spheres according to the |
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following schema: |
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.IP |
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\fIBlue\fR: global photons |
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.br |
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\fICyan\fR: precomputed global photons |
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.br |
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\fIRed\fR: caustic photons |
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.br |
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\fIGreen\fR: volume photons |
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.br |
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\fIMagenta\fR: direct photons |
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.br |
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\fIYellow\fR: contribution photons |
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|
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.SH OPTIONS |
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Options are effective for the photon map file immediately following on the |
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command line, and are reset to their defaults after completion of each dump. |
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As such they may be set individually for each photon map. |
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|
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.IP "\fB-n \fInspheres\fR" |
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Specifies the number of spheres to dump for the next photon map. The dump |
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is performed by random sampling with \fInspheres\fR as target count, hence |
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the number actually output will be approximate. \fINspheres\fR may be |
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followed by a multiplier suffix for convenience, where \fIk\fR = 10^3 and |
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\fIm\fR = 10^6, although the latter may lead to problems when processing the |
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output geometry with \fIoconv(1)\fR. The default number of spheres is 10k. |
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|
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.IP "\fB-r \fIradscale\fR" |
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Specifies a relative scale factor \fIradscale\fR for the sphere radius. The |
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sphere radius is determined automatically from an estimated average distance |
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between spheres so as to reduce clustering, assuming a uniform distribution. |
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In cases where the distribution is substantially nonuniform (e.g. highly |
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localised caustics) the radius can be manually corrected with this option. |
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The default value is 1.0. |
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|
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.SH NOTES |
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The output may contain many overlapping spheres in areas with high photon |
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density, particularly in caustics. This results in inefficient and slow |
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octree generation with \fIoconv(1)\fR. Generally this can be improved by |
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reducing \fInspheres\fR and/or \fIradscale\fR. |
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|
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.SH EXAMPLES |
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To visualise the distribution of global and caustic photons superimposed |
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on the scene geometry with 5000 and 10000 spheres, respectively: |
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.IP |
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pmapdump -n 5k global.pm -n 10k caustic.pm | |
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oconv - scene.rad > scene_pmdump.oct |
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.PP |
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Alternatively, the dump may be viewed on its own by piping the output of |
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\fIpmapdump\fR directly into \fIobjview(1)\fR (using the default number of |
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spheres in this example): |
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.IP |
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pmapdump zombo.pm | objview |
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|
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.SH AUTHOR |
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Roland Schregle (roland.schregle@{hslu.ch,gmail.com}) |
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|
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.SH COPYRIGHT |
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(c) Fraunhofer Institute for Solar Energy Systems, Lucerne University of |
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Applied Sciences and Arts. |
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|
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.SH ACKNOWLEDGEMENT |
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Development of the RADIANCE photon mapping extension was sponsored by the |
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German Research Foundation (DFG) and the Swiss National Science Foundation |
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(SNF). |
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|
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.SH "SEE ALSO" |
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mkpmap(1), objview(1), oconv(1), rpict(1), rvu(1), |
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\fIThe RADIANCE Photon Map Manual\fR |
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