| 428 |
|
Transmitting materials are an exception, where both transmission and |
| 429 |
|
reflection will use the alternate type for all rays not specifically |
| 430 |
|
targeting virtual light sources. |
| 431 |
< |
Therefore, transmitting alternate types should only have pure specular |
| 432 |
< |
reflection if they reflect at all, to maintain a valid calculation. |
| 431 |
> |
In this case, it is important that any reflections be purely specular |
| 432 |
> |
(mirror-like) and equal to the mirror's reflectivity |
| 433 |
> |
to maintain a valid result. |
| 434 |
> |
A pure diffuse reflection may be added if desired. |
| 435 |
|
.PP |
| 436 |
|
The mirror material type reflects light sources only from the front side |
| 437 |
|
of a surface, regardless of any alternate material. |
