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] |
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.br |
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.B "rpict [ options ] \-defaults" |
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+ |
.br |
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.B "rpict \-features [feat1 ..]" |
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.SH DESCRIPTION |
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.I Rpict |
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generates a picture from the RADIANCE scene given in |
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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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In the third form, a list of supported features is sent |
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to the standard output, one per line. |
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If additional arguments follow, they are checked for presence in |
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this list. |
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If a feature includes subfeatures, these may be checked as well by |
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specifying: |
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.nf |
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|
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rpict -features FeatName=subfeat1,subfeat2 |
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|
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.fi |
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If any named feature or subfeature is missing, an error is |
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reported and the program returns an error status. |
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If all of the named features are present, a zero status is returned. |
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.PP |
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Most options are followed by one or more arguments, which must be |
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separated from the option and each other by white space. |
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The exceptions to this rule are the |
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Distributed ray-tracing performs anti-aliasing by randomly sampling |
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over pixels. |
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A value of one will randomly distribute samples over full |
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pixels. |
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pixels, and is not really recommended due to the tendency of |
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samples to (nearly) coincide. |
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A value of zero samples pixel centers only. |
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A value between zero and one is usually best |
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for low-resolution images. |
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> |
A value around 0.5-0.8 is typical. |
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.TP |
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.BI -pm \ frac |
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Set the pixel motion blur to |
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specification will be calculated. |
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.TP |
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.BI -dr \ N |
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Set the number of relays for secondary sources to |
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> |
Set the number of relays for virtual sources to |
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.I N. |
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A value of 0 means that secondary sources will be ignored. |
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> |
A value of 0 means that virtual sources will be ignored. |
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A value of 1 means that sources will be made into first generation |
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secondary sources; a value of 2 means that first generation |
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secondary sources will also be made into second generation secondary |
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virtual sources; a value of 2 means that first generation |
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> |
virtual sources will also be made into second generation virtual |
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sources, and so on. |
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.TP |
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.BI -dp \ D |
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Set the secondary source presampling density to D. |
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> |
Set the virtual source presampling density to D. |
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This is the number of samples per steradian |
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that will be used to determine ahead of time whether or not |
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it is worth following shadow rays through all the reflections and/or |
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transmissions associated with a secondary source path. |
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A value of 0 means that the full secondary source path will always |
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> |
transmissions associated with a virtual source path. |
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> |
A value of 0 means that the full virtual source path will always |
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be tested for shadows if it is tested at all. |
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.TP |
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.BR \-dv |
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Set the ambient accuracy to |
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.I acc. |
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This value will approximately equal the error |
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from indirect illuminance interpolation. |
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from indirect irradiance interpolation. |
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A value of zero implies no interpolation. |
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|
.TP |
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|
.BI -ad \ N |
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Set the number of ambient divisions to |
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.I N. |
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The error in the Monte Carlo calculation of indirect |
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< |
illuminance will be inversely proportional to the square |
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> |
irradiance will be inversely proportional to the square |
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|
root of this number. |
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|
A value of zero implies no indirect calculation. |
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|
.TP |
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|
.BI -af \ fname |
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Set the ambient file to |
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|
.I fname. |
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< |
This is where indirect illuminance will be stored and retrieved. |
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< |
Normally, indirect illuminance values are kept in memory and |
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> |
This is where indirect irradiance will be stored and retrieved. |
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> |
Normally, indirect irradiance values are kept in memory and |
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|
lost when the program finishes or dies. |
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< |
By using a file, different invocations can share illuminance |
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> |
By using a file, different invocations can share irradiance |
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|
values, saving time in the computation. |
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< |
Also, by creating an ambient file during a low resolution rendering, |
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< |
better results can be obtained in a second high resolution pass. |
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> |
Also, by creating an ambient file during a low-resolution rendering, |
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> |
better results can be obtained in a second high-resolution pass. |
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> |
(It is a good idea to keep all of the calculation parameters the same, |
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> |
changing only the dimensions of the output picture.)\0 |
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|
The ambient file is in a machine-independent binary format |
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|
which may be examined with |
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.I lookamb(1). |
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.I \-ac. |
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|
Note that this is approximate as the number of cache pages is rounded to |
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|
the nearest prime. This allows adapting the cache to the available physical |
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< |
memory. In conjunction with the |
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< |
.I \-n |
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option, this is the cache size |
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< |
.I per parallel process. |
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< |
Cache performance is less sensitive to this parameter, |
| 603 |
< |
and reasonable performance can obtained with as few as 10k photons. The |
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< |
default is 1M. This option recognises multiplier suffixes (k = 1e3, M = |
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< |
1e6), both in upper and lower case. |
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> |
memory. Cache performance is less sensitive to this parameter, and reasonable |
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> |
performance can obtained with as few as 10k photons. The default is 1M. This |
| 619 |
> |
option recognises multiplier suffixes (k = 1e3, M = 1e6), both in upper and |
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> |
lower case. |
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|
.TP |
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|
.BI -me " rext gext bext" |
| 623 |
|
Set the global medium extinction coefficient to the indicated color, |
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|
divided by the given |
| 700 |
|
.I frac. |
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|
.TP |
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+ |
.BI -cs \ Ns |
| 703 |
+ |
Use |
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+ |
.I Ns |
| 705 |
+ |
bands for spectral sampling rather than the default RGB calculation space. |
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+ |
The maximum setting is controlled by the compiler macro MAXCSAMP, and |
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+ |
defaults to 24. |
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+ |
Larger values for Ns will be reduced to MAXCSAMP. |
| 709 |
+ |
.TP |
| 710 |
+ |
.BI -cw " nmA nmB" |
| 711 |
+ |
Set extrema to the given wavelengths for spectral sampling. |
| 712 |
+ |
The default is 380 and 780 nanometers. |
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+ |
The order specified does not matter. |
| 714 |
+ |
.TP |
| 715 |
+ |
.BI -pc " xr yr xg yg xb yb xw yw" |
| 716 |
+ |
Use the specified chromaticity pairs for output primaries and white |
| 717 |
+ |
point rather than the standard RGB color space. |
| 718 |
+ |
.TP |
| 719 |
+ |
.BR \-pRGB |
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+ |
Output standard RGB values (the default). |
| 721 |
+ |
.TP |
| 722 |
+ |
.BR \-pXYZ |
| 723 |
+ |
Output standard CIE XYZ tristimulus values rather than RGB. |
| 724 |
+ |
.TP |
| 725 |
|
.BI -S \ seqstart |
| 726 |
|
Instead of generating a single picture based only on the view |
| 727 |
|
parameters given on the command line, this option causes |
| 926 |
|
.PP |
| 927 |
|
rpict \-S 1 \-o frame%02d.hdr scene.oct < keyframes.vf |
| 928 |
|
.PP |
| 929 |
< |
To render ambient illuminance in photon mapping mode from a global photon |
| 929 |
> |
To render ambient irradiance in photon mapping mode from a global photon |
| 930 |
|
map global.pm via one ambient bounce, and from a caustic photon map |
| 931 |
|
caustic.pm: |
| 932 |
|
.IP "" .2i |
