| 335 |
|
.I \-i |
| 336 |
|
option so that light sources do not appear in the output. |
| 337 |
|
.TP |
| 338 |
< |
.BI -sj \ frac |
| 339 |
< |
Set the specular sampling jitter to |
| 340 |
< |
.I frac. |
| 341 |
< |
This is the degree to which the highlights are sampled |
| 342 |
< |
for rough specular materials. |
| 343 |
< |
A value of one means that all highlights will be fully sampled |
| 344 |
< |
using distributed ray tracing. |
| 338 |
> |
.BI -ss \ samp |
| 339 |
> |
Set the specular sampling to |
| 340 |
> |
.I samp. |
| 341 |
> |
For values less than 1, this is the degree to which the highlights |
| 342 |
> |
are sampled for rough specular materials. |
| 343 |
> |
A value greater than one causes multiple ray samples to be sent |
| 344 |
> |
to reduce noise at a commmesurate cost. |
| 345 |
|
A value of zero means that no jittering will take place, and all |
| 346 |
|
reflections will appear sharp even when they should be diffuse. |
| 347 |
|
This may be desirable when used in combination with image sampling |
| 365 |
|
.TP |
| 366 |
|
.BR -bv |
| 367 |
|
Boolean switch for back face visibility. |
| 368 |
< |
With this switch off, back faces of opaque objects will be invisible |
| 369 |
< |
to all rays. |
| 368 |
> |
With this switch off, back faces of all objects will be invisible |
| 369 |
> |
to view rays. |
| 370 |
|
This is dangerous unless the model was constructed such that |
| 371 |
< |
all surface normals on opaque objects face outward. |
| 371 |
> |
all surface normals face outward. |
| 372 |
|
Although turning off back face visibility does not save much |
| 373 |
|
computation time under most circumstances, it may be useful as a |
| 374 |
|
tool for scene debugging, or for seeing through one-sided walls from |
| 375 |
|
the outside. |
| 376 |
– |
This option has no effect on transparent or translucent materials. |
| 376 |
|
.TP |
| 377 |
|
.BI -av " red grn blu" |
| 378 |
|
Set the ambient value to a radiance of |
| 570 |
|
.TP |
| 571 |
|
.BI -lr \ N |
| 572 |
|
Limit reflections to a maximum of |
| 573 |
< |
.I N. |
| 573 |
> |
.I N, |
| 574 |
> |
if N is a positive integer. |
| 575 |
|
If |
| 576 |
|
.I N |
| 577 |
|
is zero, then Russian roulette is used for ray |
| 579 |
|
.I -lw |
| 580 |
|
setting (below) must be positive. |
| 581 |
|
If N is a negative integer, then this sets the upper limit |
| 582 |
< |
of reflections past which Russian roulette will not be used. |
| 582 |
> |
of reflections past which Russian roulette will be used. |
| 583 |
|
In scenes with dielectrics and total internal reflection, |
| 584 |
|
a setting of 0 (no limit) may cause a stack overflow. |
| 585 |
|
.TP |
