| 101 |
|
\fInphotons\fR with a very low average reflectance. |
| 102 |
|
|
| 103 |
|
.IP "\fB\-api \fIxmin ymin zmin xmax ymax zmax\fR" |
| 104 |
< |
Define a region of interested within which to store photons exclusively; |
| 104 |
> |
Define a region of interest within which to store photons exclusively; |
| 105 |
|
photons will only be stored within the volume bounded by the given minimum |
| 106 |
|
and maximum coordinates. Multiple instances of this option may be specified |
| 107 |
|
with cumulative effect to define compound regions of interest. This is |
| 118 |
|
|
| 119 |
|
.IP "\fB\-apM \fImaxprepass\fR" |
| 120 |
|
Maximum number of iterations of the distribution prepass before terminating |
| 121 |
< |
if some photon maps are still empty. This option is rarely needed as a |
| 122 |
< |
an aborted prepass indicates an anomaly in the geometry or an |
| 121 |
> |
if some photon maps are still empty. This option is rarely needed as |
| 122 |
> |
an aborted prepass may indicate an anomaly in the geometry or an |
| 123 |
|
incompatibility with the specified photon map types (see \fBNOTES\fR below). |
| 124 |
|
|
| 125 |
|
.IP "\fB\-apo \fImod\fR" |
| 146 |
|
\fB\-app\fR option. |
| 147 |
|
|
| 148 |
|
.IP "\fB\-apr \fIseed\fR" |
| 149 |
< |
Seed for the random number generator. This is necessary for generating |
| 150 |
< |
different photon distributions for the same octree and photon map size. |
| 149 |
> |
Seed for the random number generator. This is useful for generating |
| 150 |
> |
different photon distributions for the same octree and photon map size, |
| 151 |
> |
notably in progressive applications. |
| 152 |
|
|
| 153 |
|
.IP "\fB\-aps \fImod\fR" |
| 154 |
|
Specifies a modifier \fImod\fR defined as \fIantimatter\fR material to act |
| 169 |
|
Read virtual receiver surface modifiers from the file \fImodfile\fR as a more |
| 170 |
|
convenient alternative to multiple instances of \fB\-aps\fR. |
| 171 |
|
|
| 172 |
+ |
.IP "\fB\-ae \fImod\fR" |
| 173 |
+ |
Add \fImod\fR to the ambient exclude list, so that it will be ignored by the |
| 174 |
+ |
photon map. Objects having \fImod\fR as their modifier will not have |
| 175 |
+ |
photons deposited on them. Multiple modifiers may be given, each as separate |
| 176 |
+ |
instances of this option. |
| 177 |
+ |
.IP |
| 178 |
+ |
\fBWARNING: this is an optimisation option for advanced users and may yield |
| 179 |
+ |
biased results. It may also significantly increase photon distribution |
| 180 |
+ |
times. Use with caution!\fR |
| 181 |
+ |
|
| 182 |
+ |
.IP "\fB\-aE \fIfile\fR" |
| 183 |
+ |
Same as \fI-ae\fR, except modifiers to be exluded are read from \fIfile\fR, |
| 184 |
+ |
separated by whitespace. The RAYPATH environment variable determines which |
| 185 |
+ |
directories are searched for this file. |
| 186 |
+ |
|
| 187 |
+ |
.IP "\fB\-ai \fImod\fR" |
| 188 |
+ |
Add \fImod\fR to the ambient include list, so that it will contribute to the |
| 189 |
+ |
photon map. Only objects having \fImod\fR as their modifier will have |
| 190 |
+ |
photons deposited on them. Multiple modifiers may be given, each as separate |
| 191 |
+ |
instances of this option. Note that the ambient include and exclude options |
| 192 |
+ |
are mutually exclusive. |
| 193 |
+ |
.IP |
| 194 |
+ |
\fBWARNING: this is an optimisation option for advanced users and may yield |
| 195 |
+ |
biased results. It may also significantly increase photon distribution |
| 196 |
+ |
times. Use with caution!\fR |
| 197 |
+ |
|
| 198 |
+ |
.IP "\fB\-aI \fIfile\fR" |
| 199 |
+ |
Same as \fI-ai\fR, except modifiers to be included are read from \fIfile\fR, |
| 200 |
+ |
separated by whitespace. The RAYPATH environment variable determines which |
| 201 |
+ |
directories are searched for this file. |
| 202 |
+ |
|
| 203 |
|
.IP "\fB\-bv\fR[\fB+\fR|\fB-\fR]" |
| 204 |
|
Toggles backface visibility; enabling this causes photons to be stored and |
| 205 |
|
possibly scattered if they strike the back of a surface, otherwise they |
| 306 |
|
\fB\-apM\fR option. |
| 307 |
|
|
| 308 |
|
.SS Material Support |
| 309 |
< |
The \fIplasfunc\fR, \fImetfunc\fR, \fItransfunc\fR, \fIbrtdfunc\fR, |
| 310 |
< |
\fIplasdata\fR, \fImetdata\fR and \fItransdata\fR materials are not |
| 311 |
< |
supported by the photon mapping extension. Use the newer \fIbsdf\fR material |
| 309 |
> |
Not all materials are fully supported by the photon map extension. The |
| 310 |
> |
\fIplasfunc\fR, \fImetfunc\fR, \fItransfunc\fR, \fIplasdata\fR, |
| 311 |
> |
\fImetdata\fR and \fItransdata\fR materials currently only scatter photons |
| 312 |
> |
diffusely, and will not produce caustics. The \fIbrtdfunc\fR material only |
| 313 |
> |
produces caustics via ideal (mirror) specular reflection and transmission. |
| 314 |
> |
For more realistic scattering behaviour, use the newer \fIbsdf\fR material |
| 315 |
|
instead. |
| 316 |
|
.PP |
| 317 |
|
Virtual light sources (normally enabled with the \fImirror\fR material) are |
