man/man1/ies2rad.1

.\" RCSid "$Id: ies2rad.1,v 1.3 2007/09/04 17:36:40 greg Exp $"
.TH IES2RAD 1 6/14/96 RADIANCE
.SH NAME
ies2rad - convert IES luminaire data to RADIANCE description
.SH SYNOPSIS
.B ies2rad
[
.B options
]
[
.B input ..
]
.SH DESCRIPTION
.I Ies2rad
converts one or more IES luminaire data files to the equivalent RADIANCE
scene description.
The light source geometry will always be centered at the origin aimed
in the negative Z direction, with the 0 degree plane along the X axis.
(Note, this means that the IES "width" is actually along the Y axis,
while "length" corresponds to the X axis.)\0
Usually, two output files will be created for every input file, one
scene file (with a ".rad" suffix) and one data file (with a ".dat"
suffix).
If the IES input file includes tilt data, then another data file
will be created (with a "+.dat" suffix).
If the
.I \-s
option is used, the scene data will be sent to the standard output
instead of being written to a file.
Since the data file does not change with other options to
.I ies2rad,
this is a convenient way to specify different lamp colors and
multipliers inline in a scene description.
If the
.I \-g
option is used, then an octree file will be created (with the ".oct"
suffix).
The root portion of the output file names will be the same as the
corresponding input file, unless the
.I \-o
option is used.
The output files will be created in the current directory (no matter
which directory the input files came from) unless the
.I \-l
or
.I \-p
options are used.
.PP
.I Ies2rad
assigns light source colors based on information in a lamp lookup table.
Since most lamps are distinctly colored,
it is often desirable to override this lookup procedure and use
a neutral value that will produced color-balanced renderings.
In general, it is important to consider lamp color when an odd assortment
of fixture types is being used to illuminate the same scene, and
the rendering can always be balanced by pfilt(1) to a specific white value
later.
.TP 10n
.BI -l \ libdir
Set the library directory path to
.I libdir.
This is where all relative pathnames will begin for output file names.
For light sources that will be used by many people, this should be
set to some central location included in the RAYPATH environment variable.
The default is the current working directory.
.TP
.BI -p \ prefdir
Set the library subdirectory path to
.I prefdir.
This is the subdirectory from the library where all output files will
be placed.
It is often most convenient to use a subdirectory for the storage of
light sources, since there tend to be many files and placing them all
in one directory is very messy.
The default value is the empty string.
.TP
.BI -o \ outname
Set the output file name root to
.I outname.
This overrides the default output file name root which is the same as the
input file.
This option may be used for only one input file, and is required when
reading data from the standard input.
.TP
.BR -s
Send the scene information to the standard output rather than a
separate file.
This is appropriate when calling
.I ies2rad
from within a scene description via an inline command.
The data file(s) will still be written based on the output file name
root, but since this information is unaffected by command line options,
it is safe to have multiple invocations of
.I ies2rad
using the same input file and different output options.
The
.I \-s
option may be used for only one input file.
.TP
.BI -d units
Output dimensions are in
.I units,
which is one of the letters 'm', 'c', 'f', or 'i' for meters,
centimeters, feet or inches, respectively.
The letter specification may be followed by a slash ('/') and an
optional divisor.
For example,
.I \-dm/1000
would be millimeters.
The default output is in meters, regardless of the original units in
the IES input file.
Note that there is no space in this option.
.TP
.BI -i \ rad
Ignore the crude geometry given by the IES input file and use instead an illum
sphere with radius
.I rad.
This option may be useful when the user wishes to add a more accurate
geometric description to the light source model, though this need
is obviated by the recent LM-63-1995 specification, which uses MGF
detail geometry.
(See
.I \-g
option below.)\0
.TP
.BR -g
If the IES file contains MGF detail geometry, compile this geometry into
a separate octree and create a single instance referencing it
instead of including the converted geometry directly in the Radiance
output file.
This can result in a considerable memory savings for luminaires
which are later duplicated many times in a scene, though the
appearance may suffer for certain luminaires since the enclosed glow
sources will not light the local geometry as they would otherwise.
.TP
.BI -f \ lampdat
Use
.I lampdat
instead of the default lamp lookup table (lamp.tab) to map lamp
names to xy chromaticity and lumen depreciation data.
It is often helpful to have customized lookup tables for specific
manufacturers and applications.
.TP
.BI -t \ lamp
Use the given lamp type for all input files.
Normally,
.I ies2rad
looks at the header lines of the IES file to try and determine
what lamp is being used in the fixture.
If any of the lines is matched by a pattern in the lamp lookup
table (see the \-f option above), that color and depreciation factor will
be used instead of the default (see the \-c and \-u options).
The
.I lamp
specification is also looked up in the lamp table unless it is
set to "default", in which case the default color is used instead.
.TP
.BI \-c " red grn blu"
Use the given color if the type of the lamp is unknown or
the \-t option is set to "default".
If unspecified, the default color will be white.
.TP
.BI \-u \ lamp
Set the default lamp color according to the entry for
.I lamp
in the lookup table (see the \-f option).
This is the color that will be used if the input specification
does not match any lamp type patterns.
This option is used instead of the \-c option.
.TP
.BI \-m \ factor
Multiply all output quantities by
.I factor.
This is the best way to scale fixture brightness for different lamps, but care
should be taken when this option is applied to multiple files.
.SH EXAMPLE
To convert a single IES data file in inches with color balanced output
and 15% lumen depreciation,
creating the files "fluor01.rad" and "fluor01.dat" in the current directory:
.IP "" .2i
ies2rad \-di \-t default \-m .85 fluor01.ies
.PP
To convert three IES files of various types to tenths of a foot and put
them in the library "/usr/local/lib/ray" subdirectory "source/ies":
.IP "" .2i
ies2rad \-df/10 \-l /usr/local/lib/ray \-p source/ies ies01 ies02 ies03
.PP
To convert a single file and give the output a different name:
.IP "" .2i
ies2rad \-o fluorescent ies03
.SH ENVIRONMENT
RAYPATH         directories to search for lamp lookup table
.SH AUTHOR
Greg Ward
.SH BUGS
In pre\-1991 standard IES files, all header lines will be examined
for a lamp table string match.
In post\-1991 standard files, only those lamps with the [LAMP] or
[LAMPCAT] keywords will be searched.
The first match found in the file is always the one used.
This method of assigning colors to fixtures is less than perfect,
and the IES would do well to include explicit spectral information
somehow in their specification.
.PP
The IESNA LM\-63 specification prior to 1995 provided three basic source
shapes, rectangular, round, and elliptical.
The details of these shapes is vague at best.
Rectangular sources will always be rectangular, but ies2rad will
approximate round sources as spherical if the height is close to
or greater than the width and length, and as a ring otherwise.
Elliptical sources are treated the same as round sources.
The 1995 standard rectifies this problem by including detailed
luminaire geometry as MGF data, though nothing in the standard
requires manufacturers to provide this information.
.SH "SEE ALSO"
mgf2rad(1), oconv(1), pfilt(1), rad2mgf(1), rpict(1), xform(1)
Revision:	1.4
Committed:	Thu Jan 24 23:15:46 2008 UTC (16 years, 3 months ago) by greg
Branch:	MAIN
CVS Tags:	rad5R2, rad4R2P2, rad5R0, rad5R1, rad4R2, rad4R1, rad4R0, rad3R9, rad4R2P1, rad5R3
Changes since 1.3:	+4 -2 lines
Log Message:	Fixed reversed orientation for anisotropic distrubutions
#	Content
1	.\" RCSid "$Id: ies2rad.1,v 1.3 2007/09/04 17:36:40 greg Exp $"
2	.TH IES2RAD 1 6/14/96 RADIANCE
3	.SH NAME
4	ies2rad - convert IES luminaire data to RADIANCE description
5	.SH SYNOPSIS
6	.B ies2rad
7	[
8	.B options
9	]
10	[
11	.B input ..
12	]
13	.SH DESCRIPTION
14	.I Ies2rad
15	converts one or more IES luminaire data files to the equivalent RADIANCE
16	scene description.
17	The light source geometry will always be centered at the origin aimed
18	in the negative Z direction, with the 0 degree plane along the X axis.
19	(Note, this means that the IES "width" is actually along the Y axis,
20	while "length" corresponds to the X axis.)\0
21	Usually, two output files will be created for every input file, one
22	scene file (with a ".rad" suffix) and one data file (with a ".dat"
23	suffix).
24	If the IES input file includes tilt data, then another data file
25	will be created (with a "+.dat" suffix).
26	If the
27	.I \-s
28	option is used, the scene data will be sent to the standard output
29	instead of being written to a file.
30	Since the data file does not change with other options to
31	.I ies2rad,
32	this is a convenient way to specify different lamp colors and
33	multipliers inline in a scene description.
34	If the
35	.I \-g
36	option is used, then an octree file will be created (with the ".oct"
37	suffix).
38	The root portion of the output file names will be the same as the
39	corresponding input file, unless the
40	.I \-o
41	option is used.
42	The output files will be created in the current directory (no matter
43	which directory the input files came from) unless the
44	.I \-l
45	or
46	.I \-p
47	options are used.
48	.PP
49	.I Ies2rad
50	assigns light source colors based on information in a lamp lookup table.
51	Since most lamps are distinctly colored,
52	it is often desirable to override this lookup procedure and use
53	a neutral value that will produced color-balanced renderings.
54	In general, it is important to consider lamp color when an odd assortment
55	of fixture types is being used to illuminate the same scene, and
56	the rendering can always be balanced by pfilt(1) to a specific white value
57	later.
58	.TP 10n
59	.BI -l \ libdir
60	Set the library directory path to
61	.I libdir.
62	This is where all relative pathnames will begin for output file names.
63	For light sources that will be used by many people, this should be
64	set to some central location included in the RAYPATH environment variable.
65	The default is the current working directory.
66	.TP
67	.BI -p \ prefdir
68	Set the library subdirectory path to
69	.I prefdir.
70	This is the subdirectory from the library where all output files will
71	be placed.
72	It is often most convenient to use a subdirectory for the storage of
73	light sources, since there tend to be many files and placing them all
74	in one directory is very messy.
75	The default value is the empty string.
76	.TP
77	.BI -o \ outname
78	Set the output file name root to
79	.I outname.
80	This overrides the default output file name root which is the same as the
81	input file.
82	This option may be used for only one input file, and is required when
83	reading data from the standard input.
84	.TP
85	.BR -s
86	Send the scene information to the standard output rather than a
87	separate file.
88	This is appropriate when calling
89	.I ies2rad
90	from within a scene description via an inline command.
91	The data file(s) will still be written based on the output file name
92	root, but since this information is unaffected by command line options,
93	it is safe to have multiple invocations of
94	.I ies2rad
95	using the same input file and different output options.
96	The
97	.I \-s
98	option may be used for only one input file.
99	.TP
100	.BI -d units
101	Output dimensions are in
102	.I units,
103	which is one of the letters 'm', 'c', 'f', or 'i' for meters,
104	centimeters, feet or inches, respectively.
105	The letter specification may be followed by a slash ('/') and an
106	optional divisor.
107	For example,
108	.I \-dm/1000
109	would be millimeters.
110	The default output is in meters, regardless of the original units in
111	the IES input file.
112	Note that there is no space in this option.
113	.TP
114	.BI -i \ rad
115	Ignore the crude geometry given by the IES input file and use instead an illum
116	sphere with radius
117	.I rad.
118	This option may be useful when the user wishes to add a more accurate
119	geometric description to the light source model, though this need
120	is obviated by the recent LM-63-1995 specification, which uses MGF
121	detail geometry.
122	(See
123	.I \-g
124	option below.)\0
125	.TP
126	.BR -g
127	If the IES file contains MGF detail geometry, compile this geometry into
128	a separate octree and create a single instance referencing it
129	instead of including the converted geometry directly in the Radiance
130	output file.
131	This can result in a considerable memory savings for luminaires
132	which are later duplicated many times in a scene, though the
133	appearance may suffer for certain luminaires since the enclosed glow
134	sources will not light the local geometry as they would otherwise.
135	.TP
136	.BI -f \ lampdat
137	Use
138	.I lampdat
139	instead of the default lamp lookup table (lamp.tab) to map lamp
140	names to xy chromaticity and lumen depreciation data.
141	It is often helpful to have customized lookup tables for specific
142	manufacturers and applications.
143	.TP
144	.BI -t \ lamp
145	Use the given lamp type for all input files.
146	Normally,
147	.I ies2rad
148	looks at the header lines of the IES file to try and determine
149	what lamp is being used in the fixture.
150	If any of the lines is matched by a pattern in the lamp lookup
151	table (see the \-f option above), that color and depreciation factor will
152	be used instead of the default (see the \-c and \-u options).
153	The
154	.I lamp
155	specification is also looked up in the lamp table unless it is
156	set to "default", in which case the default color is used instead.
157	.TP
158	.BI \-c " red grn blu"
159	Use the given color if the type of the lamp is unknown or
160	the \-t option is set to "default".
161	If unspecified, the default color will be white.
162	.TP
163	.BI \-u \ lamp
164	Set the default lamp color according to the entry for
165	.I lamp
166	in the lookup table (see the \-f option).
167	This is the color that will be used if the input specification
168	does not match any lamp type patterns.
169	This option is used instead of the \-c option.
170	.TP
171	.BI \-m \ factor
172	Multiply all output quantities by
173	.I factor.
174	This is the best way to scale fixture brightness for different lamps, but care
175	should be taken when this option is applied to multiple files.
176	.SH EXAMPLE
177	To convert a single IES data file in inches with color balanced output
178	and 15% lumen depreciation,
179	creating the files "fluor01.rad" and "fluor01.dat" in the current directory:
180	.IP "" .2i
181	ies2rad \-di \-t default \-m .85 fluor01.ies
182	.PP
183	To convert three IES files of various types to tenths of a foot and put
184	them in the library "/usr/local/lib/ray" subdirectory "source/ies":
185	.IP "" .2i
186	ies2rad \-df/10 \-l /usr/local/lib/ray \-p source/ies ies01 ies02 ies03
187	.PP
188	To convert a single file and give the output a different name:
189	.IP "" .2i
190	ies2rad \-o fluorescent ies03
191	.SH ENVIRONMENT
192	RAYPATH directories to search for lamp lookup table
193	.SH AUTHOR
194	Greg Ward
195	.SH BUGS
196	In pre\-1991 standard IES files, all header lines will be examined
197	for a lamp table string match.
198	In post\-1991 standard files, only those lamps with the [LAMP] or
199	[LAMPCAT] keywords will be searched.
200	The first match found in the file is always the one used.
201	This method of assigning colors to fixtures is less than perfect,
202	and the IES would do well to include explicit spectral information
203	somehow in their specification.
204	.PP
205	The IESNA LM\-63 specification prior to 1995 provided three basic source
206	shapes, rectangular, round, and elliptical.
207	The details of these shapes is vague at best.
208	Rectangular sources will always be rectangular, but ies2rad will
209	approximate round sources as spherical if the height is close to
210	or greater than the width and length, and as a ring otherwise.
211	Elliptical sources are treated the same as round sources.
212	The 1995 standard rectifies this problem by including detailed
213	luminaire geometry as MGF data, though nothing in the standard
214	requires manufacturers to provide this information.
215	.SH "SEE ALSO"
216	mgf2rad(1), oconv(1), pfilt(1), rad2mgf(1), rpict(1), xform(1)