| 70 |
|
to the letter 'c'. |
| 71 |
|
This view is like a standard perspective vertically, but projected |
| 72 |
|
on a cylinder horizontally (like a soupcan's-eye view). |
| 73 |
< |
Two fisheye views are provided as well; 'h' yields a hemispherical fisheye |
| 74 |
< |
view and 'a' results in angular fisheye distortion. |
| 73 |
> |
Three fisheye views are provided as well; 'h' yields a hemispherical fisheye |
| 74 |
> |
view, 'a' results in angular fisheye distortion, and 's' |
| 75 |
> |
results in a planisphere (stereographic) projection. |
| 76 |
|
A hemispherical fisheye is a projection of the hemisphere onto a circle. |
| 77 |
|
The maximum view angle for this type is 180 degrees. |
| 78 |
|
An angular fisheye view is defined such that distance from the center of |
| 79 |
|
the image is proportional to the angle from the central view direction. |
| 80 |
|
An angular fisheye can display a full 360 degrees. |
| 81 |
+ |
A planisphere fisheye view maintains angular relationships between lines, |
| 82 |
+ |
and is commonly used for sun path analysis. |
| 83 |
+ |
This is more commonly known as a |
| 84 |
+ |
"stereographic projection," but we avoid the term here so as not to |
| 85 |
+ |
confuse it with a stereoscopic pair. |
| 86 |
+ |
A planisphere fisheye can display up to (but not including) 360 degrees, |
| 87 |
+ |
although distortion becomes extreme as this limit is approached. |
| 88 |
|
Note that there is no space between the view type |
| 89 |
|
option and its single letter argument. |
| 90 |
|
.TP |
| 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 |
| 571 |
|
.TP |
| 572 |
|
.BI -lr \ N |
| 573 |
|
Limit reflections to a maximum of |
| 574 |
< |
.I N. |
| 574 |
> |
.I N, |
| 575 |
> |
if N is a positive integer. |
| 576 |
|
If |
| 577 |
|
.I N |
| 578 |
|
is zero, then Russian roulette is used for ray |
| 580 |
|
.I -lw |
| 581 |
|
setting (below) must be positive. |
| 582 |
|
If N is a negative integer, then this sets the upper limit |
| 583 |
< |
of reflections past which Russian roulette will not be used. |
| 583 |
> |
of reflections past which Russian roulette will be used. |
| 584 |
|
In scenes with dielectrics and total internal reflection, |
| 585 |
|
a setting of 0 (no limit) may cause a stack overflow. |
| 586 |
|
.TP |
| 797 |
|
The default is to print warnings, so the first appearance of |
| 798 |
|
this option turns them off. |
| 799 |
|
.SH EXAMPLE |
| 800 |
< |
rpict \-vp 10 5 3 \-vd 1 \-.5 0 scene.oct > scene.pic |
| 800 |
> |
rpict \-vp 10 5 3 \-vd 1 \-.5 0 scene.oct > scene.hdr |
| 801 |
|
.PP |
| 802 |
< |
rpict \-S 1 \-o frame%02d.pic scene.oct < keyframes.vf |
| 802 |
> |
rpict \-S 1 \-o frame%02d.hdr scene.oct < keyframes.vf |
| 803 |
|
.SH ENVIRONMENT |
| 804 |
|
RAYPATH the directories to check for auxiliary files. |
| 805 |
|
.SH FILES |
