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Comparing ray/doc/man/man1/rtcontrib.1 (file contents):
Revision 1.7 by greg, Thu Jun 2 04:47:26 2005 UTC vs.
Revision 1.15 by greg, Sun Feb 5 22:22:20 2006 UTC

# Line 7 | Line 7 | rtcontrib - compute contribution coefficients in a RAD
7   [
8   .B "\-n nprocs"
9   ][
10 + .B \-V
11 + ][
12 + .B \-fo
13 + |
14 + .B \-r
15 + ][
16   .B "\-e expr"
17   ][
18   .B "\-f source"
# Line 14 | Line 20 | rtcontrib - compute contribution coefficients in a RAD
20   .B "\-o ospec"
21   ][
22   .B "\-b binv"
23 + ][
24 + .B "\-bn nbins"
25   ]
26 < .B "\-m mod .."
26 > {
27 > .B "\-m mod | \-M file"
28 > }
29 > ..
30   [
31   .B $EVAR
32   ]
# Line 30 | Line 41 | rtrace options
41   .B "rtcontrib [ options ] \-defaults"
42   .SH DESCRIPTION
43   .I Rtcontrib
44 < computes ray contributions (i.e., color coefficients)
44 > computes ray coefficients
45   for objects whose modifiers are named in one or more
46   .I \-m
47   settings.
48   These modifiers are usually materials associated with
49   light sources or sky domes, and must directly modify some geometric
50   primitives to be considered in the output.
51 + A modifier list may also be read from a file using the
52 + .I \-M
53 + option.
54 + The RAYPATH environment variable determines directories to search for
55 + this file.
56 + (No search takes place if a file name begins with a '.', '/' or '~'
57 + character.)\0
58 + .PP
59 + By setting the boolean
60 + .I \-V
61 + option, you may instruct
62 + .I rtcontrib
63 + to report the contribution from each material rather than the ray
64 + coefficient.
65 + This is particularly useful for light sources with directional output
66 + distributions, whose value would otherwise be lost in the shuffle.
67 + With the default
68 + .I -V-
69 + setting, the output of rtcontrib is a coefficient that must be multiplied
70 + by the radiance of each material to arrive at a final contribution.
71 + This is more convenient for computing daylight coefficeints, or cases
72 + where the actual radiance is not desired.
73 + Use the
74 + .I -V+
75 + setting when you wish to simply sum together contributions
76 + (with possible adjustment factors) to obtain a final radiance value.
77 + Combined with the
78 + .I \-i
79 + or
80 + .I \-I
81 + option, irradiance contributions are reported by
82 + .I \-V+
83 + rather than radiance, and
84 + .I \-V-
85 + coefficients contain an additonal factor of PI.
86 + .PP
87   The output of
88   .I rtcontrib
89   has many potential uses.
# Line 51 | Line 98 | systems, such as luminaires, light pipes, and shading
98   .I Rtcontrib
99   calls
100   .I rtrace(1)
101 < with the -oTW option to calculate the daughter ray
101 > with the -oTW (or -oTV) option to calculate the daughter ray
102   contributions for each input ray, and the output tallies
103   are sent to one or more destinations according to the given
104   .I \-o
# Line 59 | Line 106 | specification.
106   If a destination begins with an exclamation mark ('!'), then
107   a pipe is opened to a command and data is sent to its standard input.
108   Otherwise, the destination is treated as a file.
109 < (An existing file of the same name is clobbered.)\0
109 > An existing file of the same name will not be clobbered, unless the
110 > .I \-fo
111 > option is given.
112 > If instead the
113 > .I \-r
114 > option is specified, data recovery is attempted on existing files.
115   If an output specification contains a "%s" format, this will be
116   replaced by the modifier name.
117   The
# Line 70 | Line 122 | this will be applied to a "%d" format in the output fi
122   specification if present.
123   The actual bin number is computed at run time based on ray direction
124   and surface intersection, as described below.
125 + If the number of bins is known in advance, it should be specified with the
126 + .I \-bn
127 + option, and this is critical for output files containing multiple values
128 + per record.
129 + Since bin numbers start from 0, the bin count is always equal to
130 + the last bin plus 1.
131 + Set the this value to 0 if the bin count is unknown (the default).
132   The most recent
133 < .I \-b
133 > .I \-b,
134 > .I \-bn
135   and
136   .I \-o
137   options to the left of each
# Line 109 | Line 169 | Unlike
169   will search the RADIANCE library directories for each file given in a
170   .I \-f
171   option.
112 – (No search takes place if a file name begins with a '.', '/' or '~'
113 – character.)\0
172   .PP
173   If no
174   .I \-o
# Line 191 | Line 249 | pcomb -c 100 90 75 c_light1.pic -c 50 55 57 c_light2.p
249   .PP
250   To compute an array of illuminance contributions according to a Tregenza sky:
251   .IP "" .2i
252 < rtcontrib -b tbin -o sky.dat -m skyglow -b 0 -o ground.dat -m groundglow
252 > rtcontrib -I+ -b tbin -o sky.dat -m skyglow -b 0 -o ground.dat -m groundglow
253   @render.opt -f tregenza.cal scene.oct < test.dat
254   .SH ENVIRONMENT
255 < RAYPATH         path to search for -f files
255 > RAYPATH         path to search for -f and -M files
256   .SH AUTHOR
257   Greg Ward
258   .SH "SEE ALSO"

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