| 139 |
|
.TP |
| 140 |
|
.BR n |
| 141 |
|
Do not produce any secondary sources. |
| 142 |
< |
All input will be passed to the output unaffected. |
| 142 |
> |
All input will be passed to the output unaffected, except any |
| 143 |
> |
void surfaces will be removed. |
| 144 |
|
.TP |
| 145 |
|
.BI b =real |
| 146 |
|
Do not produce a secondary source for a surface if its average |
| 174 |
|
is zero, then a diffuse source is assumed and no distribution is |
| 175 |
|
created. |
| 176 |
|
.TP |
| 177 |
+ |
.BI d =string |
| 178 |
+ |
Set the surface Bidirectional Scattering Distribution Function (BSDF) |
| 179 |
+ |
to the given file. |
| 180 |
+ |
The RADIANCE library path will be searched if the file does not begin |
| 181 |
+ |
with a '.' or '~' character. |
| 182 |
+ |
This file must contain an LBNL Window 6 XML specification of a valid |
| 183 |
+ |
BSDF for the given surface, and all rays will be interpreted through |
| 184 |
+ |
this function. |
| 185 |
+ |
The orientation of the BSDF may be controlled with the |
| 186 |
+ |
.I u |
| 187 |
+ |
setting, described below. |
| 188 |
+ |
The thickness of the surface may be controlled with the |
| 189 |
+ |
.I t |
| 190 |
+ |
setting. |
| 191 |
+ |
If this variable has no setting or an integer is specified, |
| 192 |
+ |
.I mkillum |
| 193 |
+ |
returns to the default behavior of computing the output distribution |
| 194 |
+ |
directly. |
| 195 |
+ |
.TP |
| 196 |
|
.BI s =integer |
| 197 |
|
Set the number of ray samples per direction to |
| 198 |
|
.I integer. |
| 213 |
|
as its alternate material. |
| 214 |
|
The default is |
| 215 |
|
.I l-. |
| 216 |
+ |
.TP |
| 217 |
+ |
.BI u =[+|-]{X|Y|Z} |
| 218 |
+ |
The given axis will be considered "up" for the purposes of interpreting |
| 219 |
+ |
BSDF data specified with the |
| 220 |
+ |
.I d |
| 221 |
+ |
variable. |
| 222 |
+ |
The BSDF will be reoriented relative to the surface as necessary to keep |
| 223 |
+ |
the up vector in the vertical plane that contains this axis and the |
| 224 |
+ |
surface normal. |
| 225 |
+ |
The default value is +Z. |
| 226 |
+ |
.TP |
| 227 |
+ |
.BI t =real |
| 228 |
+ |
Set the surface thickness to |
| 229 |
+ |
.I real |
| 230 |
+ |
in world coordinates. |
| 231 |
+ |
This value is used for determining where to start rays that need to begin |
| 232 |
+ |
on the opposite side of the surface, specifically to compute the incoming |
| 233 |
+ |
distribution for a BSDF computation. |
| 234 |
+ |
The default value is 0. |
| 235 |
|
.SH EXAMPLES |
| 236 |
|
The following command generates illum's corresponding to geometry |
| 237 |
|
in the files "it1.rad" and "it2.rad": |
| 240 |
|
.PP |
| 241 |
|
The output file "illums.rad" would then be combined with the original |
| 242 |
|
scene geometry to create a more easily rendered composite. |
| 243 |
+ |
.SH ENVIRONMENT |
| 244 |
+ |
RAYPATH the directories to check for auxiliary files. |
| 245 |
|
.SH AUTHOR |
| 246 |
|
Greg Ward |
| 247 |
|
.SH ACKNOWLEDGEMENT |
