61 |
|
If the |
62 |
|
.I \-n |
63 |
|
option is specified with a value greater than 1, multiple |
64 |
– |
.I rtrace |
64 |
|
processes will be used to accelerate computation on a shared |
65 |
|
memory machine. |
66 |
|
Note that there is no benefit to using more processes |
128 |
|
systems, such as luminaires, light pipes, and shading devices. |
129 |
|
.PP |
130 |
|
.I Rcontrib |
131 |
< |
calls |
132 |
< |
.I rtrace(1) |
134 |
< |
with the \-oTW (or \-oTV) option to calculate the daughter ray |
135 |
< |
contributions for each input ray, and the output tallies |
136 |
< |
are sent to one or more destinations according to the given |
131 |
> |
sends the accumulated rays tallies |
132 |
> |
to one or more destinations according to the given |
133 |
|
.I \-o |
134 |
|
specification. |
135 |
|
If a destination begins with an exclamation mark ('!'), then |
158 |
|
specification if present. |
159 |
|
The actual bin number is computed at run time based on ray direction |
160 |
|
and surface intersection, as described below. |
161 |
< |
If the number of bins is known in advance, it should be specified with the |
161 |
> |
The number of bins must be specified in advance with the |
162 |
|
.I \-bn |
163 |
|
option, and this is critical for output files containing multiple values |
164 |
|
per record. |
192 |
|
.I \-b |
193 |
|
expression is defined for a particular modifier, |
194 |
|
the bin number will be evaluated at run time for each |
195 |
< |
ray contribution from |
200 |
< |
.I rtrace. |
195 |
> |
ray contribution. |
196 |
|
Specifically, each ray's world intersection point will be assigned to |
197 |
|
the variables Px, Py, and Pz, and the normalized ray direction |
198 |
|
will be assigned to Dx, Dy, and Dz. |