| 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 aBSDF |
| 951 |
+ |
.PP |
| 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 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 aBSDF id |
| 963 |
+ |
5+ BSDFfile ux uy uz funcfile transform |
| 964 |
+ |
0 |
| 965 |
+ |
0|3|6|9 |
| 966 |
+ |
rfdif gfdif bfdif |
| 967 |
+ |
rbdif gbdif bbdif |
| 968 |
+ |
rtdif gtdif btdif |
| 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 aBSDF. |
| 973 |
+ |
.LP |
| 974 |
|
.UL Antimatter |
| 975 |
|
.PP |
| 976 |
|
Antimatter is a material that can "subtract" volumes from other volumes. |
| 1593 |
|
in Lausanne, Switzerland. |
| 1594 |
|
.NH 1 |
| 1595 |
|
References |
| 1596 |
+ |
.LP |
| 1597 |
+ |
Wang, Taoning, Gregory Ward, Eleanor Lee, |
| 1598 |
+ |
``Efficient modeling of optically-complex, non-coplanar |
| 1599 |
+ |
exterior shading: Validation of matrix algebraic methods,'' |
| 1600 |
+ |
.I "Energy & Buildings", |
| 1601 |
+ |
vol. 174, pp. 464-83, Sept. 2018. |
| 1602 |
+ |
.LP |
| 1603 |
+ |
Lee, Eleanor S., David Geisler-Moroder, Gregory Ward, |
| 1604 |
+ |
``Modeling the direct sun component in buildings using matrix |
| 1605 |
+ |
algebraic approaches: Methods and validation,'' |
| 1606 |
+ |
.I Solar Energy, |
| 1607 |
+ |
vol. 160, 15 January 2018, pp 380-395. |
| 1608 |
|
.LP |
| 1609 |
|
Ward, G., M. Kurt & N. Bonneel, |
| 1610 |
|
``Reducing Anisotropic BSDF Measurement to Common Practice,'' |
