| 172 |
|
is zero, then a diffuse source is assumed and no distribution is |
| 173 |
|
created. |
| 174 |
|
.TP |
| 175 |
– |
.BI d =string |
| 176 |
– |
Set the surface Bidirectional Scattering Distribution Function (BSDF) |
| 177 |
– |
to the given file. |
| 178 |
– |
The RADIANCE library path will be searched if the file does not begin |
| 179 |
– |
with a '.' or '~' character. |
| 180 |
– |
This file must contain an LBNL Window 6 XML specification of a valid |
| 181 |
– |
BSDF for the given surface, and all rays will be interpreted through |
| 182 |
– |
this function, which may be produced by the Radiance |
| 183 |
– |
.I genBSDF(1) |
| 184 |
– |
program. |
| 185 |
– |
The orientation of the BSDF may be controlled with the |
| 186 |
– |
.I u |
| 187 |
– |
setting, described below. |
| 188 |
– |
If this variable has no setting or an integer is specified, |
| 189 |
– |
.I mkillum |
| 190 |
– |
returns to the default behavior of computing the output distribution |
| 191 |
– |
directly. |
| 192 |
– |
.TP |
| 175 |
|
.BI s =integer |
| 176 |
|
Set the number of ray samples per direction to |
| 177 |
|
.I integer. |
| 192 |
|
as its alternate material. |
| 193 |
|
The default is |
| 194 |
|
.I l-. |
| 213 |
– |
.TP |
| 214 |
– |
.BI u =[+|-]{X|Y|Z} |
| 215 |
– |
The given axis will be considered "up" for the purposes of interpreting |
| 216 |
– |
BSDF data specified with the |
| 217 |
– |
.I d |
| 218 |
– |
variable. |
| 219 |
– |
The BSDF will be reoriented relative to the surface as necessary to keep |
| 220 |
– |
the up vector in the vertical plane that contains this axis and the |
| 221 |
– |
surface normal, corresponding to an azimuth of 90 degrees. |
| 222 |
– |
The default up vector is +Z. |
| 223 |
– |
.TP |
| 224 |
– |
.BI t =real |
| 225 |
– |
Set the surface thickness to |
| 226 |
– |
.I real |
| 227 |
– |
in world coordinates. |
| 228 |
– |
This value is used for determining where to start rays that need to begin |
| 229 |
– |
on the opposite side of a fenestration system, specifically |
| 230 |
– |
to compute the incoming distribution for a BSDF computation. |
| 231 |
– |
If the thickness is set to 0 and a BSDF contains detailed geometry, |
| 232 |
– |
it will be translated and output as part of the new description, provided the |
| 233 |
– |
.I l- |
| 234 |
– |
option is also in effect. |
| 235 |
– |
(This currently works only for rectangular polygons.)\0 |
| 236 |
– |
The default thickness is 0. |
| 195 |
|
.SH EXAMPLES |
| 196 |
|
The following command generates illum's corresponding to geometry |
| 197 |
|
in the files "it1.rad" and "it2.rad": |
