| 1 |
greg |
1.6 |
.\" RCSid "$Id: mksource.1,v 1.5 2007/09/04 17:36:40 greg Exp $"
|
| 2 |
greg |
1.1 |
.TH MKSOURCE 1 04/11/05 RADIANCE
|
| 3 |
|
|
.SH NAME
|
| 4 |
|
|
mksource - compute distant sources for RADIANCE image-based lighting
|
| 5 |
|
|
.SH SYNOPSIS
|
| 6 |
|
|
.B mksource
|
| 7 |
|
|
[
|
| 8 |
|
|
.B "\-d nsamps"
|
| 9 |
|
|
][
|
| 10 |
|
|
.B "\-t thresh"
|
| 11 |
|
|
][
|
| 12 |
|
|
.B "\-a maxang"
|
| 13 |
|
|
]
|
| 14 |
|
|
[
|
| 15 |
|
|
.B octree
|
| 16 |
|
|
]
|
| 17 |
|
|
.SH DESCRIPTION
|
| 18 |
|
|
.I Mksource
|
| 19 |
|
|
produces a RADIANCE scene description of distant illum
|
| 20 |
|
|
sources corresponding to bright, concentrated regions in
|
| 21 |
|
|
the given ambient environment.
|
| 22 |
|
|
Any local geometry is ignored in the input octree, which
|
| 23 |
greg |
1.2 |
should be derived from a captured light probe and modeled
|
| 24 |
|
|
as a distant hemispherical or spherical glow source.
|
| 25 |
greg |
1.1 |
The output sources may then be combined with this environment
|
| 26 |
|
|
to produce a more efficient scene for rendering, faster and
|
| 27 |
|
|
less prone to sampling artifacts.
|
| 28 |
|
|
.PP
|
| 29 |
|
|
The
|
| 30 |
|
|
.I \-d
|
| 31 |
|
|
option may be used to specify the number of ray samples, which
|
| 32 |
|
|
defaults to 262,000.
|
| 33 |
greg |
1.3 |
Calculation time is roughly proportional to this setting, and the
|
| 34 |
|
|
default is fine enough to resolve sources the size of the sun
|
| 35 |
greg |
1.1 |
(half a degree) or larger.
|
| 36 |
|
|
.PP
|
| 37 |
|
|
The
|
| 38 |
|
|
.I \-t
|
| 39 |
|
|
option may be used to manually set the radiance threshold for
|
| 40 |
|
|
sources, in watts/sr/meter^2.
|
| 41 |
greg |
1.4 |
The default uses the top 2 percentile of the environment, which
|
| 42 |
greg |
1.1 |
is usally a good value.
|
| 43 |
|
|
.PP
|
| 44 |
|
|
The
|
| 45 |
|
|
.I \-a
|
| 46 |
|
|
option may be used to specify a maximum source diameter,
|
| 47 |
|
|
which defaults to 15 degrees.
|
| 48 |
|
|
.I Mkillum
|
| 49 |
|
|
silently enforces a maximum of 180 degrees for this option.
|
| 50 |
|
|
.PP
|
| 51 |
|
|
If no input octree is specified, the standard input is read.
|
| 52 |
|
|
.SH EXAMPLE
|
| 53 |
|
|
To add sources with a maximum size of 20 degrees
|
| 54 |
greg |
1.6 |
to the environment described in environ.oct:
|
| 55 |
greg |
1.1 |
.IP "" .2i
|
| 56 |
greg |
1.5 |
mksource \-a 20 environ.oct > srcs.rad
|
| 57 |
greg |
1.1 |
.br
|
| 58 |
greg |
1.5 |
oconv \-i environ.oct srcs.rad > env+srcs.oct
|
| 59 |
greg |
1.1 |
.SH AUTHOR
|
| 60 |
|
|
Greg Ward
|
| 61 |
|
|
.SH "SEE ALSO"
|
| 62 |
|
|
mkillum(1), rpict(1), rvu(1)
|
