| 1 |
.\" RCSid "$Id$" |
| 2 |
.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 |
should be derived from a captured light probe. |
| 24 |
The output sources may then be combined with this environment |
| 25 |
to produce a more efficient scene for rendering, faster and |
| 26 |
less prone to sampling artifacts. |
| 27 |
.PP |
| 28 |
The |
| 29 |
.I \-d |
| 30 |
option may be used to specify the number of ray samples, which |
| 31 |
defaults to 262,000. |
| 32 |
Calculation time is roughly proportional to accuracy, and the |
| 33 |
default is fine enough to find sources the size of the sun |
| 34 |
(half a degree) or larger. |
| 35 |
.PP |
| 36 |
The |
| 37 |
.I \-t |
| 38 |
option may be used to manually set the radiance threshold for |
| 39 |
sources, in watts/sr/meter^2. |
| 40 |
The default uses the top 1 percentile of the environment, which |
| 41 |
is usally a good value. |
| 42 |
.PP |
| 43 |
The |
| 44 |
.I \-a |
| 45 |
option may be used to specify a maximum source diameter, |
| 46 |
which defaults to 15 degrees. |
| 47 |
.I Mkillum |
| 48 |
silently enforces a maximum of 180 degrees for this option. |
| 49 |
.PP |
| 50 |
If no input octree is specified, the standard input is read. |
| 51 |
.SH EXAMPLE |
| 52 |
To add sources with a maximum size of 20 degrees |
| 53 |
to the enviornment described in environ.oct: |
| 54 |
.IP "" .2i |
| 55 |
mksource -a 20 environ.oct > srcs.rad |
| 56 |
.br |
| 57 |
oconv -i environ.oct srcs.rad > env+srcs.oct |
| 58 |
.SH AUTHOR |
| 59 |
Greg Ward |
| 60 |
.SH "SEE ALSO" |
| 61 |
mkillum(1), rpict(1), rvu(1) |
