| 11 |
|
][ |
| 12 |
|
.B "\-r 'rcontrib opts...'" |
| 13 |
|
][ |
| 14 |
+ |
.B "\-W" |
| 15 |
+ |
][ |
| 16 |
+ |
.B "\-s 'x=string;y=string'" |
| 17 |
+ |
][ |
| 18 |
|
.B "\-t{3|4} Nlog2" |
| 19 |
|
][ |
| 20 |
+ |
.B "{+|-}C" |
| 21 |
+ |
][ |
| 22 |
+ |
.B "{+|-}a" |
| 23 |
+ |
][ |
| 24 |
|
.B "{+|-}forward" |
| 25 |
|
][ |
| 26 |
|
.B "{+|-}backward" |
| 34 |
|
[ |
| 35 |
|
.B "geom .." |
| 36 |
|
] |
| 37 |
+ |
.br |
| 38 |
+ |
or |
| 39 |
+ |
.br |
| 40 |
+ |
.B genBSDF |
| 41 |
+ |
.B "\-recover tempdir" |
| 42 |
|
.SH DESCRIPTION |
| 43 |
|
.I GenBSDF |
| 44 |
|
computes a bidirectional scattering distribution function from |
| 67 |
|
To turn off backward components, use the |
| 68 |
|
.I \-backward |
| 69 |
|
option. |
| 70 |
< |
Computing both components takes about twice as long as one component. |
| 70 |
> |
Computing both components takes about twice as long as one component, but |
| 71 |
> |
is recommended when rays will be impinging from either side. |
| 72 |
|
.PP |
| 73 |
+ |
The |
| 74 |
+ |
.I \+C |
| 75 |
+ |
option specifies that the output XML should include tristimulus |
| 76 |
+ |
color information, which is interpreted by the rendering programs. |
| 77 |
+ |
The default option |
| 78 |
+ |
.I \-C |
| 79 |
+ |
reduces all BSDF data to grayscale. |
| 80 |
+ |
If the input is spectral and a |
| 81 |
+ |
.I \-cs |
| 82 |
+ |
parameter of 9 or more is specified as part of the rendering |
| 83 |
+ |
.I \-r |
| 84 |
+ |
option list, then full spectral result will be |
| 85 |
+ |
reduced to an XYZ-equivalent CIE color space in the XML output. |
| 86 |
+ |
.PP |
| 87 |
+ |
The |
| 88 |
+ |
.I \-a |
| 89 |
+ |
option turns off reciprocity averaging for tensor tree output. |
| 90 |
+ |
Normally on (+a), this ensures that each tensor-tree hemisphere follows symmetry |
| 91 |
+ |
implied by Helmholtz reciprocity, and is designed to reduce ray sampling noise. |
| 92 |
+ |
However, for some systems, reciprocity averaging can actually make the output worse. |
| 93 |
+ |
.PP |
| 94 |
|
The geometry must fit a rectangular profile, whose width is along the X-axis, |
| 95 |
|
height is in the Y-axis, and depth is in the Z-axis. |
| 96 |
|
The positive Z-axis points into the room, and the input geometry should |
| 116 |
|
This value defaults to 2000 samples distributed over the incoming plane |
| 117 |
|
for each of the 145 Klems hemisphere directions. |
| 118 |
|
.PP |
| 119 |
< |
In some cases, the processing time may be reduced by the |
| 119 |
> |
On multi-core machines, processing time may be reduced by the |
| 120 |
|
.I \-n |
| 121 |
|
option, which specifies the number of simultaneous |
| 87 |
– |
.I rtrace(1) |
| 122 |
|
processes to run in |
| 123 |
|
.I rcontrib(1). |
| 124 |
|
The |
| 129 |
|
command line. |
| 130 |
|
.PP |
| 131 |
|
The |
| 132 |
+ |
.I \-W |
| 133 |
+ |
option is passed to |
| 134 |
+ |
.I wrapBSDF(1) |
| 135 |
+ |
to prepare the XML file for WINDOW6. |
| 136 |
+ |
Any |
| 137 |
+ |
.I \-s |
| 138 |
+ |
parameters are passed to the |
| 139 |
+ |
.I \-f |
| 140 |
+ |
option of |
| 141 |
+ |
.I wrapBSDF, |
| 142 |
+ |
controlling XML fields such as |
| 143 |
+ |
the Manufacturer (e.g., -s m=MF) and device Name (e.g, -s n=NM). |
| 144 |
+ |
.PP |
| 145 |
+ |
The |
| 146 |
|
.I \-t4 |
| 147 |
|
mode computes a non-uniform BSDF represented as a rank 4 tensor tree, |
| 148 |
|
suitable for use in the Radiance rendering tools. |
| 177 |
|
Again, the parameter to this option sets the maximum resolution as |
| 178 |
|
a power of 2 in each dimension, but in this case there is one less |
| 179 |
|
dimension being sampled. |
| 180 |
+ |
.PP |
| 181 |
+ |
The |
| 182 |
+ |
.I \-recover |
| 183 |
+ |
option is available for continuing calculations that were killed by |
| 184 |
+ |
the system or the user. |
| 185 |
+ |
Unfortunately, genBSDF puts its temporary files in a directory |
| 186 |
+ |
that is often cleaned up after reboot, so this may not always work. |
| 187 |
|
.SH EXAMPLE |
| 188 |
|
To create a BSDF description including geometry from a set of venetian blinds: |
| 189 |
|
.IP "" .2i |
| 206 |
|
.SH AUTHOR |
| 207 |
|
Greg Ward |
| 208 |
|
.SH "SEE ALSO" |
| 209 |
< |
dctimestep(1), genklemsamp(1), genskyvec(1), mkillum(1), |
| 210 |
< |
pkgBSDF(1), rcontrib(1), rtrace(1) |
| 209 |
> |
dctimestep(1), gendaymtx(1), genklemsamp(1), genskyvec(1), mkillum(1), |
| 210 |
> |
pkgBSDF(1), rcomb(1), rcontrib(1), rfluxmtx(1), rmtxop(1), rtrace(1) wrapBSDF(1) |
