| 18 |
|
] |
| 19 |
|
.br |
| 20 |
|
.B "rpict [ options ] \-defaults" |
| 21 |
+ |
.br |
| 22 |
+ |
.B "rpict \-features [feat1 ..]" |
| 23 |
|
.SH DESCRIPTION |
| 24 |
|
.I Rpict |
| 25 |
|
generates a picture from the RADIANCE scene given in |
| 43 |
|
for the options (modified by those options present) |
| 44 |
|
are printed with a brief explanation. |
| 45 |
|
.PP |
| 46 |
+ |
In the third form, a list of supported features is sent |
| 47 |
+ |
to the standard output, one per line. |
| 48 |
+ |
If additional arguments follow, they are checked for presence in |
| 49 |
+ |
this list. |
| 50 |
+ |
If a feature includes subfeatures, these may be checked as well by |
| 51 |
+ |
specifying: |
| 52 |
+ |
.nf |
| 53 |
+ |
|
| 54 |
+ |
rpict -features FeatName=subfeat1,subfeat2 |
| 55 |
+ |
|
| 56 |
+ |
.fi |
| 57 |
+ |
If any named feature or subfeature is missing, an error is |
| 58 |
+ |
reported and the program returns an error status. |
| 59 |
+ |
If all of the named features are present, a zero status is returned. |
| 60 |
+ |
.PP |
| 61 |
|
Most options are followed by one or more arguments, which must be |
| 62 |
|
separated from the option and each other by white space. |
| 63 |
|
The exceptions to this rule are the |
| 228 |
|
Distributed ray-tracing performs anti-aliasing by randomly sampling |
| 229 |
|
over pixels. |
| 230 |
|
A value of one will randomly distribute samples over full |
| 231 |
< |
pixels. |
| 231 |
> |
pixels, and is not really recommended due to the tendency of |
| 232 |
> |
samples to (nearly) coincide. |
| 233 |
|
A value of zero samples pixel centers only. |
| 234 |
< |
A value between zero and one is usually best |
| 217 |
< |
for low-resolution images. |
| 234 |
> |
A value around 0.5-0.8 is typical. |
| 235 |
|
.TP |
| 236 |
|
.BI -pm \ frac |
| 237 |
|
Set the pixel motion blur to |
| 327 |
|
specification will be calculated. |
| 328 |
|
.TP |
| 329 |
|
.BI -dr \ N |
| 330 |
< |
Set the number of relays for secondary sources to |
| 330 |
> |
Set the number of relays for virtual sources to |
| 331 |
|
.I N. |
| 332 |
< |
A value of 0 means that secondary sources will be ignored. |
| 332 |
> |
A value of 0 means that virtual sources will be ignored. |
| 333 |
|
A value of 1 means that sources will be made into first generation |
| 334 |
< |
secondary sources; a value of 2 means that first generation |
| 335 |
< |
secondary sources will also be made into second generation secondary |
| 334 |
> |
virtual sources; a value of 2 means that first generation |
| 335 |
> |
virtual sources will also be made into second generation virtual |
| 336 |
|
sources, and so on. |
| 337 |
|
.TP |
| 338 |
|
.BI -dp \ D |
| 339 |
< |
Set the secondary source presampling density to D. |
| 339 |
> |
Set the virtual source presampling density to D. |
| 340 |
|
This is the number of samples per steradian |
| 341 |
|
that will be used to determine ahead of time whether or not |
| 342 |
|
it is worth following shadow rays through all the reflections and/or |
| 343 |
< |
transmissions associated with a secondary source path. |
| 344 |
< |
A value of 0 means that the full secondary source path will always |
| 343 |
> |
transmissions associated with a virtual source path. |
| 344 |
> |
A value of 0 means that the full virtual source path will always |
| 345 |
|
be tested for shadows if it is tested at all. |
| 346 |
|
.TP |
| 347 |
|
.BR \-dv |
| 425 |
|
This is the maximum number of diffuse bounces computed by the indirect |
| 426 |
|
calculation. A value of zero implies no indirect calculation. |
| 427 |
|
.IP |
| 428 |
< |
In photon mapping mode (see |
| 428 |
> |
This value defaults to 1 in photon mapping mode (see |
| 429 |
|
.I -ap |
| 430 |
< |
below), a positive value implies that global photon irradiance is |
| 414 |
< |
always computed via |
| 430 |
> |
below), implying that global photon irradiance is always computed via |
| 431 |
|
.I one |
| 432 |
< |
ambient bounce. A negative value enables a preview mode that directly |
| 433 |
< |
visualises the irradiance from the global photon map without any ambient |
| 434 |
< |
bounces. |
| 432 |
> |
ambient bounce; this behaviour applies to any positive number of ambient |
| 433 |
> |
bounces, regardless of the actual value specified. A negative value enables |
| 434 |
> |
a preview mode that directly visualises the irradiance from the global |
| 435 |
> |
photon map without any ambient bounces. |
| 436 |
|
.TP |
| 437 |
|
.BI -ar \ res |
| 438 |
|
Set the ambient resolution to |
| 456 |
|
Set the ambient accuracy to |
| 457 |
|
.I acc. |
| 458 |
|
This value will approximately equal the error |
| 459 |
< |
from indirect illuminance interpolation. |
| 459 |
> |
from indirect irradiance interpolation. |
| 460 |
|
A value of zero implies no interpolation. |
| 461 |
|
.TP |
| 462 |
|
.BI -ad \ N |
| 463 |
|
Set the number of ambient divisions to |
| 464 |
|
.I N. |
| 465 |
|
The error in the Monte Carlo calculation of indirect |
| 466 |
< |
illuminance will be inversely proportional to the square |
| 466 |
> |
irradiance will be inversely proportional to the square |
| 467 |
|
root of this number. |
| 468 |
|
A value of zero implies no indirect calculation. |
| 469 |
|
.TP |
| 476 |
|
.BI -af \ fname |
| 477 |
|
Set the ambient file to |
| 478 |
|
.I fname. |
| 479 |
< |
This is where indirect illuminance will be stored and retrieved. |
| 480 |
< |
Normally, indirect illuminance values are kept in memory and |
| 479 |
> |
This is where indirect irradiance will be stored and retrieved. |
| 480 |
> |
Normally, indirect irradiance values are kept in memory and |
| 481 |
|
lost when the program finishes or dies. |
| 482 |
< |
By using a file, different invocations can share illuminance |
| 482 |
> |
By using a file, different invocations can share irradiance |
| 483 |
|
values, saving time in the computation. |
| 484 |
< |
Also, by creating an ambient file during a low resolution rendering, |
| 485 |
< |
better results can be obtained in a second high resolution pass. |
| 484 |
> |
Also, by creating an ambient file during a low-resolution rendering, |
| 485 |
> |
better results can be obtained in a second high-resolution pass. |
| 486 |
> |
(It is a good idea to keep all of the calculation parameters the same, |
| 487 |
> |
changing only the dimensions of the output picture.)\0 |
| 488 |
|
The ambient file is in a machine-independent binary format |
| 489 |
|
which may be examined with |
| 490 |
|
.I lookamb(1). |
| 559 |
|
above), caustic photon irradiance is evaluated at primary rays, and |
| 560 |
|
indirect inscattering in |
| 561 |
|
.I mist |
| 562 |
< |
is accounted for by volume photons. |
| 562 |
> |
is accounted for by volume photons. Contribution photons are treated as |
| 563 |
> |
global photons by |
| 564 |
> |
.I rpict. |
| 565 |
|
.IP |
| 566 |
|
Additionally specifying |
| 567 |
|
.I bwidth2 |
| 578 |
|
is invariably looked up. |
| 579 |
|
.IP |
| 580 |
|
Using direct photons replaces the direct calculation with density estimates |
| 581 |
< |
for debugging and validation of photon emission. |
| 581 |
> |
for debugging and validation of photon emission. |
| 582 |
|
.TP |
| 583 |
|
.BI -am " frac" |
| 584 |
< |
Coefficient for maximum search radius for photon map lookups. The search |
| 585 |
< |
radius is automatically determined based on the average photon distance to the |
| 586 |
< |
distribution's centre of gravity, and scaled by this coefficient. Increase this |
| 587 |
< |
value if multiple warnings about short photon lookups are issued. |
| 584 |
> |
Maximum search radius for photon map lookups. Without this option, an |
| 585 |
> |
initial maximum search radius is estimated for each photon map from the |
| 586 |
> |
average photon distance to the distribution's centre of gravity. It is then |
| 587 |
> |
adapted to the photon density in subsequent lookups. This option imposes a |
| 588 |
> |
global fixed maximum search radius for |
| 589 |
> |
.I all |
| 590 |
> |
photon maps, thus defeating the automatic adaptation. It is useful when |
| 591 |
> |
multiple warnings about short photon lookups are issued. Note that this |
| 592 |
> |
option does not conflict with the bandwidth specified with the |
| 593 |
> |
.I \-ap |
| 594 |
> |
option; the number of photons found will not exceed the latter, but may be |
| 595 |
> |
lower if the maximum search radius contains fewer photons, thus resulting in |
| 596 |
> |
short lookups. Setting this radius too large, on the other hand, may |
| 597 |
> |
degrade performance. |
| 598 |
|
.TP |
| 599 |
+ |
.BI -ac " pagesize" |
| 600 |
+ |
Set the photon cache page size when using out-of-core photon mapping. The |
| 601 |
+ |
photon cache reduces disk I/O incurred by on-demand loading (paging) of |
| 602 |
+ |
photons, and thus increases performance. This |
| 603 |
+ |
is expressed as a (float) multiple of the density estimate bandwidth |
| 604 |
+ |
specified with |
| 605 |
+ |
.I \-ap |
| 606 |
+ |
under the assumption that photon lookups are local to a cache page. Cache |
| 607 |
+ |
performance is sensitive to this parameter: larger pagesizes will reduce the |
| 608 |
+ |
paging frequency at the expense of higher latency when paging does occur. |
| 609 |
+ |
Sensible values are in the range 4 (default) to 16. |
| 610 |
+ |
.TP |
| 611 |
+ |
.BI -aC " cachesize" |
| 612 |
+ |
Set the total number of photons cached when using out-of-core photon |
| 613 |
+ |
mapping, taking into account the pagesize specified by |
| 614 |
+ |
.I \-ac. |
| 615 |
+ |
Note that this is approximate as the number of cache pages is rounded to |
| 616 |
+ |
the nearest prime. This allows adapting the cache to the available physical |
| 617 |
+ |
memory. Cache performance is less sensitive to this parameter, and reasonable |
| 618 |
+ |
performance can obtained with as few as 10k photons. The default is 1M. This |
| 619 |
+ |
option recognises multiplier suffixes (k = 1e3, M = 1e6), both in upper and |
| 620 |
+ |
lower case. |
| 621 |
+ |
.TP |
| 622 |
|
.BI -me " rext gext bext" |
| 623 |
|
Set the global medium extinction coefficient to the indicated color, |
| 624 |
|
in units of 1/distance (distance in world coordinates). |
| 681 |
|
termination, and the |
| 682 |
|
.I -lw |
| 683 |
|
setting (below) must be positive. |
| 684 |
< |
If N is a negative integer, then this sets the upper limit |
| 685 |
< |
of reflections past which Russian roulette will be used. |
| 684 |
> |
If N is a negative integer, then this limits the maximum |
| 685 |
> |
number of reflections even with Russian roulette. |
| 686 |
|
In scenes with dielectrics and total internal reflection, |
| 687 |
|
a setting of 0 (no limit) may cause a stack overflow. |
| 688 |
|
.TP |
| 903 |
|
.PP |
| 904 |
|
rpict \-S 1 \-o frame%02d.hdr scene.oct < keyframes.vf |
| 905 |
|
.PP |
| 906 |
< |
To render ambient illuminance in photon mapping mode from a global photon |
| 906 |
> |
To render ambient irradiance in photon mapping mode from a global photon |
| 907 |
|
map global.pm via one ambient bounce, and from a caustic photon map |
| 908 |
|
caustic.pm: |
| 909 |
|
.IP "" .2i |
| 929 |
|
Greg Ward |
| 930 |
|
.SH "SEE ALSO" |
| 931 |
|
getinfo(1), lookamb(1), mkpmap(1), oconv(1), pdfblur(1), pfilt(1), |
| 932 |
< |
pinterp(1), pmblur(1), printf(3), ra_rgbe(1), rad(1), rtrace(1), rvu(1) |
| 932 |
> |
pinterp(1), pmblur(1), printf(3), ra_rgbe(1), rad(1), rpiece(1), rtpict(1), rtrace(1), rvu(1) |
