| 947 |
|
Unlike other data-driven material types, the BSDF type is fully |
| 948 |
|
supported and all parts of the distribution are properly sampled. |
| 949 |
|
.LP |
| 950 |
< |
.UL sBSDF |
| 950 |
> |
.UL aBSDF |
| 951 |
|
.PP |
| 952 |
< |
The sBSDF material is identical to the BSDF type with two important |
| 952 |
> |
The aBSDF material is identical to the BSDF type with two important |
| 953 |
|
differences. |
| 954 |
|
First, proxy geometry is not supported, so there is no thickness parameter. |
| 955 |
< |
Second, an sBSDF is assumed to have some specular through component, which |
| 955 |
> |
Second, an aBSDF is assumed to have some specular through component |
| 956 |
> |
(the 'a' stands for "aperture"), which |
| 957 |
|
is treated specially during the direct calculation and when viewing the |
| 958 |
|
material. |
| 959 |
|
Based on the BSDF data, the coefficient of specular transmission is |
| 960 |
|
determined and used for modifying unscattered shadow and view rays. |
| 961 |
|
.DS |
| 962 |
< |
mod sBSDF id |
| 962 |
> |
mod aBSDF id |
| 963 |
|
5+ BSDFfile ux uy uz funcfile transform |
| 964 |
|
0 |
| 965 |
|
0|3|6|9 |
| 969 |
|
.DE |
| 970 |
|
.LP |
| 971 |
|
If a material has no specular transmitted component, it is much better |
| 972 |
< |
to use the BSDF type with a zero thickness than to use sBSDF. |
| 972 |
> |
to use the BSDF type with a zero thickness than to use aBSDF. |
| 973 |
|
.LP |
| 974 |
|
.UL Antimatter |
| 975 |
|
.PP |
