| 9 |
|
][ |
| 10 |
|
.B \-V |
| 11 |
|
][ |
| 12 |
+ |
.B "\-c count" |
| 13 |
+ |
][ |
| 14 |
|
.B \-fo |
| 15 |
|
| |
| 16 |
|
.B \-r |
| 58 |
|
(No search takes place if a file name begins with a '.', '/' or '~' |
| 59 |
|
character.)\0 |
| 60 |
|
.PP |
| 61 |
+ |
If the |
| 62 |
+ |
.I \-n |
| 63 |
+ |
option is specified with a value greater than 1, multiple |
| 64 |
+ |
.I rtrace |
| 65 |
+ |
processes will be used to accelerate computation on a shared |
| 66 |
+ |
memory machine. |
| 67 |
+ |
Note that there is no benefit to using more processes |
| 68 |
+ |
than there are local CPUs available to do the work, and the |
| 69 |
+ |
.I rtcontrib |
| 70 |
+ |
process itself may use a considerable amount of CPU time. |
| 71 |
+ |
.PP |
| 72 |
|
By setting the boolean |
| 73 |
|
.I \-V |
| 74 |
|
option, you may instruct |
| 97 |
|
.I \-V- |
| 98 |
|
coefficients contain an additonal factor of PI. |
| 99 |
|
.PP |
| 100 |
+ |
The |
| 101 |
+ |
.I \-c |
| 102 |
+ |
option tells |
| 103 |
+ |
.I rtcontrib |
| 104 |
+ |
how many rays to accumulate for each record. |
| 105 |
+ |
The default value is 1, meaning a full record will be produced for |
| 106 |
+ |
each input ray. |
| 107 |
+ |
For values greater than 1, contributions will be averaged together |
| 108 |
+ |
over the given number of input rays. |
| 109 |
+ |
If set to zero, only a single record will be produced at the very |
| 110 |
+ |
end, corresponding to the sum of all rays given on the input |
| 111 |
+ |
(rather than the average). |
| 112 |
+ |
This is equivalent to passing all the output records through a program like |
| 113 |
+ |
.I total(1) |
| 114 |
+ |
to sum RGB values together, but is much more efficient. |
| 115 |
+ |
Using this option, it is possible to reverse sampling, sending rays from |
| 116 |
+ |
a parallel source such as the sun to a diffuse surface, for example. |
| 117 |
+ |
Note that output flushing via zero-direction rays is disabled |
| 118 |
+ |
for accumulated evaluations. |
| 119 |
+ |
.PP |
| 120 |
|
The output of |
| 121 |
|
.I rtcontrib |
| 122 |
|
has many potential uses. |
| 145 |
|
If instead the |
| 146 |
|
.I \-r |
| 147 |
|
option is specified, data recovery is attempted on existing files. |
| 148 |
+ |
(If |
| 149 |
+ |
.I "\-c 0" |
| 150 |
+ |
is used together with the |
| 151 |
+ |
.I \-r |
| 152 |
+ |
option, existing files are read in and new ray evaluations are added |
| 153 |
+ |
to the previous results, providing a convenient means for |
| 154 |
+ |
progressive simulation.)\0 |
| 155 |
|
If an output specification contains a "%s" format, this will be |
| 156 |
|
replaced by the modifier name. |
| 157 |
|
The |
| 166 |
|
.I \-bn |
| 167 |
|
option, and this is critical for output files containing multiple values |
| 168 |
|
per record. |
| 169 |
+ |
A variable or constant name may be given for this parameter if |
| 170 |
+ |
it has been defined via a previous |
| 171 |
+ |
.I \-f |
| 172 |
+ |
or |
| 173 |
+ |
.I \-e |
| 174 |
+ |
option. |
| 175 |
|
Since bin numbers start from 0, the bin count is always equal to |
| 176 |
|
the last bin plus 1. |
| 177 |
|
Set the this value to 0 if the bin count is unknown (the default). |
| 182 |
|
.I \-o |
| 183 |
|
options to the left of each |
| 184 |
|
.I \-m |
| 185 |
< |
setting affect only that modifier. |
| 186 |
< |
(The ordering of other options is unimportant.)\0 |
| 185 |
> |
setting are the ones used for that modifier. |
| 186 |
> |
The ordering of other options is unimportant, except for |
| 187 |
> |
.I \-x |
| 188 |
> |
and |
| 189 |
> |
.I \-y |
| 190 |
> |
if the |
| 191 |
> |
.I \-c |
| 192 |
> |
is 0, when they control the resolution string |
| 193 |
> |
produced in the corresponding output. |
| 194 |
|
.PP |
| 195 |
|
If a |
| 196 |
|
.I \-b |
| 265 |
|
.I pcomb(1) |
| 266 |
|
and related tools. |
| 267 |
|
.PP |
| 215 |
– |
If the |
| 216 |
– |
.I \-n |
| 217 |
– |
option is specified with a value greater than 1, multiple |
| 218 |
– |
.I rtrace |
| 219 |
– |
processes will be used to accelerate computation on a shared |
| 220 |
– |
memory machine. |
| 221 |
– |
Note that there is no benefit to using more processes |
| 222 |
– |
than there are local CPUs available to do the work, and the |
| 223 |
– |
.I rtcontrib |
| 224 |
– |
process itself may use a considerable amount of CPU time. |
| 225 |
– |
.PP |
| 268 |
|
Options may be given on the command line and/or read from the |
| 269 |
|
environment and/or read from a file. |
| 270 |
|
A command argument beginning with a dollar sign ('$') is immediately |
| 282 |
|
.IP "" .2i |
| 283 |
|
vwrays \-ff \-x 1024 \-y 1024 \-vf best.vf | |
| 284 |
|
rtcontrib \-ffc `vwrays \-d \-x 1024 \-y 1024 \-vf best.vf` |
| 285 |
< |
@render.opt \-o c_%s.pic \-m light1 \-m light2 scene.oct |
| 285 |
> |
@render.opt \-o c_%s.hdr \-m light1 \-m light2 scene.oct |
| 286 |
|
.PP |
| 287 |
|
These images may then be recombined using the desired outputs |
| 288 |
|
of light1 and light2: |
| 289 |
|
.IP "" .2i |
| 290 |
< |
pcomb \-c 100 90 75 c_light1.pic \-c 50 55 57 c_light2.pic > combined.pic |
| 290 |
> |
pcomb \-c 100 90 75 c_light1.hdr \-c 50 55 57 c_light2.hdr > combined.hdr |
| 291 |
|
.PP |
| 292 |
|
To compute an array of illuminance contributions according to a Tregenza sky: |
| 293 |
|
.IP "" .2i |
| 298 |
|
.SH AUTHOR |
| 299 |
|
Greg Ward |
| 300 |
|
.SH "SEE ALSO" |
| 301 |
< |
cnt(1), getinfo(1), pcomb(1), pfilt(1), ra_rgbe(1), |
| 302 |
< |
rcalc(1), rpict(1), rtrace(1), vwrays(1), ximage(1) |
| 301 |
> |
cnt(1), genklemsamp(1), getinfo(1), pcomb(1), pfilt(1), ra_rgbe(1), |
| 302 |
> |
rcalc(1), rpict(1), rtrace(1), total(1), vwrays(1), ximage(1) |
