ViewVC Help

View File | Revision Log | Show Annotations | Download File | Root Listing

root/Development/ray/doc/man/man1/rtcontrib.1

Comparing ray/doc/man/man1/rtcontrib.1 (file contents):
Revision 1.2 by greg, Thu May 26 18:53:04 2005 UTC vs.
Revision 1.11 by greg, Sat Jul 23 19:53:36 2005 UTC

#	Line 1 | Line 1
1		.\" RCSid "$Id$"
2	<	.TH RPIECE 1 5/25/05 RADIANCE
2	>	.TH RTCONTRIB 1 5/25/05 RADIANCE
3		.SH NAME
4	<	rtcontrib - compute contributions in a RADIANCE scene
4	>	rtcontrib - compute contribution coefficients in a RADIANCE scene
5		.SH SYNOPSIS
6		.B rtcontrib
7		[
8		.B "\-n nprocs"
9		][
10	+	.B \-r
11	+	][
12		.B "\-e expr"
13		][
14		.B "\-f source"
15		][
16	<	.B "\-o fspec"
16	>	.B "\-o ospec"
17		][
18		.B "\-b binv"
19		]
20	<	.B "\-m mod .."
20	>	{
21	>	.B "\-m mod | \-M file"
22	>	}
23	>	..
24		[
25		.B $EVAR
26		]
#	Line 26 | Line 31 | rtcontrib - compute contributions in a RADIANCE scene
31		rtrace options
32		]
33		.B octree
34	+	.br
35	+	.B "rtcontrib [ options ] \-defaults"
36		.SH DESCRIPTION
37		.I Rtcontrib
38		computes ray contributions (i.e., color coefficients)
#	Line 35 | Line 42 | settings.
42		These modifiers are usually materials associated with
43		light sources or sky domes, and must directly modify some geometric
44		primitives to be considered in the output.
45	<	The computed contributions can then be used in linear combination to
45	>	A modifier list may also be read from a file using the
46	>	.I \-M
47	>	option.
48	>	The RAYPATH environment variable determines directories to search for
49	>	this file.
50	>	(No search takes place if a file name begins with a '.', '/' or '~'
51	>	character.)\0
52	>	.PP
53	>	The output of
54	>	.I rtcontrib
55	>	has many potential uses.
56	>	Source contributions can be used as components in linear combination to
57		reproduce any desired variation, e.g., simulating lighting controls or
58		changing sky conditions via daylight coefficients.
59		More generally,
60		.I rtcontrib
61	<	may be used to compute input-output relationships in optical
62	<	systems, such as light pipes and shading devices.
61	>	can be used to compute arbitrary input-output relationships in optical
62	>	systems, such as luminaires, light pipes, and shading devices.
63		.PP
64		.I Rtcontrib
65		calls
66		.I rtrace(1)
67	<	to calculate the contributions for each input ray,
68	<	and the output tallies are sent to one or more files according to the
67	>	with the -oTW option to calculate the daughter ray
68	>	contributions for each input ray, and the output tallies
69	>	are sent to one or more destinations according to the given
70		.I \-o
71		specification.
72	+	If a destination begins with an exclamation mark ('!'), then
73	+	a pipe is opened to a command and data is sent to its standard input.
74	+	Otherwise, the destination is treated as a file.
75	+	An existing file of the same name is clobbered, unless the
76	+	.I \-r
77	+	option is specified, in which case data recovery is attempted.
78		If an output specification contains a "%s" format, this will be
79		replaced by the modifier name.
80		The
#	Line 58 | Line 83 | option may be used to further define
83		a "bin number" within each object if finer resolution is needed, and
84		this will be applied to a "%d" format in the output file
85		specification if present.
86	<	(The actual bin number is computed at run time based on ray direction
87	<	and surface intersection, as described below.)\0
86	>	The actual bin number is computed at run time based on ray direction
87	>	and surface intersection, as described below.
88		The most recent
89		.I \-b
90		and
#	Line 80 | Line 105 | the variables Px, Py, and Pz, and the normalized ray d
105		will be assigned to Dx, Dy, and Dz.
106		These parameters may be combined with definitions given in
107		.I \-e
108	<	options and files read in
108	>	arguments and files read using the
109		.I \-f
110	<	options, to compute the bin, which will be
110	>	option.
111	>	The computed bin value will be
112		rounded to the nearest whole number.
113		This mechanism allows the user to define precise regions or directions
114		they wish to accumulate, such as the Tregenza sky discretization,
115		which would be otherwise impossible to specify
116		as a set of RADIANCE primitives.
117	+	The rules and predefined functions available for these expressions are
118	+	described in the
119	+	.I rcalc(1)
120	+	man page.
121	+	Unlike
122	+	.I rcalc,
123	+	.I rtcontrib
124	+	will search the RADIANCE library directories for each file given in a
125	+	.I \-f
126	+	option.
127		.PP
128		If no
129		.I \-o
130		specification is given, results are written on the standard output in order
131		of modifier (as given on the command line) then bin number.
132	<	Concatenated data is also sent to a lone output file (i.e., an initial
132	>	Concatenated data is also sent to a single destination (i.e., an initial
133		.I \-o
134		specification without formatting strings).
135		If a "%s" format appears but no "%d" in the
#	Line 168 | Line 204 | pcomb -c 100 90 75 c_light1.pic -c 50 55 57 c_light2.p
204		.PP
205		To compute an array of illuminance contributions according to a Tregenza sky:
206		.IP "" .2i
207	<	rtcontrib -b tbin -o sky.dat -m skyglow -b 0 -o ground.dat -m groundglow
207	>	rtcontrib -I+ -b tbin -o sky.dat -m skyglow -b 0 -o ground.dat -m groundglow
208		@render.opt -f tregenza.cal scene.oct < test.dat
209	+	.SH ENVIRONMENT
210	+	RAYPATH         path to search for -f and -M files
211		.SH AUTHOR
212		Greg Ward
213		.SH "SEE ALSO"

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines (old)
>	Changed lines (new)