| 7 |
|
[ |
| 8 |
|
.B "\-n nprocs" |
| 9 |
|
][ |
| 10 |
+ |
.B \-V |
| 11 |
+ |
][ |
| 12 |
+ |
.B \-fo |
| 13 |
+ |
| |
| 14 |
|
.B \-r |
| 15 |
|
][ |
| 16 |
|
.B "\-e expr" |
| 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. |
| 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. |
| 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 |
| 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, unless the |
| 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, in which case data recovery is attempted. |
| 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 |
| 233 |
|
To compute the proportional contributions from sources modified |
| 234 |
|
by "light1" vs. "light2" on a set of illuminance values: |
| 235 |
|
.IP "" .2i |
| 236 |
< |
rtcontrib -I+ @render.opt -o c_%s.dat -m light1 -m light2 scene.oct < test.dat |
| 236 |
> |
rtcontrib \-I+ @render.opt \-o c_%s.dat \-m light1 \-m light2 scene.oct < test.dat |
| 237 |
|
.PP |
| 238 |
|
To generate a pair of images corresponding to these two lights' |
| 239 |
|
contributions: |
| 240 |
|
.IP "" .2i |
| 241 |
< |
vwrays -ff -x 1024 -y 1024 -vf best.vf | |
| 242 |
< |
rtcontrib -ffc `vwrays -d -x 1024 -y 1024 -vf best.vf` |
| 243 |
< |
@render.opt -o c_%s.pic -m light1 -m light2 scene.oct |
| 241 |
> |
vwrays \-ff \-x 1024 \-y 1024 \-vf best.vf | |
| 242 |
> |
rtcontrib \-ffc `vwrays \-d \-x 1024 \-y 1024 \-vf best.vf` |
| 243 |
> |
@render.opt \-o c_%s.pic \-m light1 \-m light2 scene.oct |
| 244 |
|
.PP |
| 245 |
|
These images may then be recombined using the desired outputs |
| 246 |
|
of light1 and light2: |
| 247 |
|
.IP "" .2i |
| 248 |
< |
pcomb -c 100 90 75 c_light1.pic -c 50 55 57 c_light2.pic > combined.pic |
| 248 |
> |
pcomb \-c 100 90 75 c_light1.pic \-c 50 55 57 c_light2.pic > combined.pic |
| 249 |
|
.PP |
| 250 |
|
To compute an array of illuminance contributions according to a Tregenza sky: |
| 251 |
|
.IP "" .2i |
| 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 |
| 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 and -M files |
| 255 |
> |
RAYPATH path to search for \-f and \-M files |
| 256 |
|
.SH AUTHOR |
| 257 |
|
Greg Ward |
| 258 |
|
.SH "SEE ALSO" |
