| 586 |
|
3 red green blue |
| 587 |
|
</pre> |
| 588 |
|
|
| 589 |
+ |
While alternate materials that are reflective will appear as normal, |
| 590 |
+ |
indirect rays will use the mirror's reflectance rather than the |
| 591 |
+ |
alternate type. |
| 592 |
+ |
Transmitting materials are an exception, where both transmission and |
| 593 |
+ |
reflection will use the alternate type for all rays not specifically |
| 594 |
+ |
targeting virtual light sources. |
| 595 |
+ |
In this case, it is important that any reflections be purely specular |
| 596 |
+ |
(mirror-like) and equal to the mirror's reflectivity |
| 597 |
+ |
to maintain a valid result. |
| 598 |
+ |
A pure diffuse reflection may be added if desired. |
| 599 |
+ |
|
| 600 |
+ |
<p> |
| 601 |
+ |
|
| 602 |
+ |
The mirror material type reflects light sources only from the front side |
| 603 |
+ |
of a surface, regardless of any alternate material. |
| 604 |
+ |
If virtual source generation is desired on both sides, two coincident |
| 605 |
+ |
surfaces with opposite normal orientations may be employed to achieve |
| 606 |
+ |
this effect. |
| 607 |
+ |
The reflectance and alternate material type may be |
| 608 |
+ |
different for the overlapped surfaces, |
| 609 |
+ |
and the two sides will behave accordingly. |
| 610 |
+ |
|
| 611 |
|
<p> |
| 612 |
|
|
| 613 |
|
<dt> |
