Table of Contents
rad - render a RADIANCE scene
rad [ -s ][ -n ][ -t ][ -e ][ -V ][ -w ][ -v view ][ -o
device ] rfile [ VAR=value .. ]
Rad is an executive program that reads the given rfile and
makes appropriate calls to oconv(1), mkillum(1), rpict(1),
pfilt(1), and/or rview(1) to render a specific scene.
Variables in rfile give input files and qualitative
information about the rendering(s) desired that together
enable rad to intelligently set parameter values and control
Normally, commands are echoed to the standard output as they
are executed. The -s option tells rad to do its work
silently. The -n option tells rad not to take any action
(ie. not to actually execute any commands). The -t option
tells rad to bring rendering files up to date relative to
the input (scene description) files, without performing any
actual calculations. If no octree exists, it is still
necessary to run oconv(1) to create one, since the -t option
will not create invalid (i.e. empty) files, and a valid
octree is necessary for the correct operation of rad. The -e
option tells rad to explicate all variables used for the
simulation, including default values not specified in the
input file, and print them on the standard output.
Normally, rad will produce one picture for each view given
in rfile. The -v option may be used to specify a single
desired view. The view argument may either be a complete
view specification (enclosed in quotes and beginning with an
optional identifier) or a number or single-word identifier
to match a view defined in rfile. If the argument is one of
the standard view identifiers, it may or may not be further
elaborated in rfile. (See "view" variable description,
below.) If the argument does not match any views in rfile
and is not one of the standard views, no rendering will take
place. This may be convenient when the only action desired
of rad is the rebuilding of the octree. In particular, the
argument "0" will never match a view.
If the -V option is given, each view will be printed on the
standard output before being applied, in a form suitable for
use in a view file or rpict rendering sequence. This is
helpful as feedback or for accessing the rad view
assignments without necessarily starting a rendering.
By default, rad will run rpict and pfilt to produce a
picture for each view. The -o option specifies an output
device for rview (usually "x11") and runs this interactive
program instead, using the first view in rfile or the view
given with the -v option as the starting point.
Additional variable settings may be added or overridden on
the command line following rfile. Upper case variables
specified more than once will result in a warning message
(unless the -w option is present), and the last value given
will be the one used.
The -w option turns off warnings about multiply and
Rendering variable assignments appear one per line in rfile.
The name of the variable is followed by an equals sign ('=')
and its value(s). The end of line may be escaped with a
backslash ('\'), though it is not usually necessary since
additional variable values may be given in multiple
assignments. Variables that should have only one value are
given in upper case. Variables that may have multiple
values are given in lower case. Variables may be
abbreviated by their first three letters. Comments in rfile
start with a pound sign ('#') and proceed to the end of
The rendering variables, their interpretations and default
values are given below.
- The name of the octree file. The default name is
the same as rfile but with any suffix replaced by
EXPOSURE This variable tells rad how to adjust the exposure
for display. It is important to set this variable
properly as it is used to determine the ambient
value. An appropriate setting may be discovered
by running rview and noting the exposure given by
the "exposure =" command. As in rview and pfilt,
the exposure setting may be given either as a
multiplier or as a number of f-stop adjustments
(eg. +2 or -1.5). There is no default value for
this variable. If it is not given, an average
level will be computed by pfilt and the ambient
value will be set to 10 for exterior zones and
0.01 for interior zones.
- This variable specifies the volume of interest for
this simulation. The first word is either
"Interior" or "Exterior", depending on whether the
zone is to be observed from the inside or the
outside, respectively. (A single letter may be
given, and case does not matter.) The following
six numbers are the minimum and maximum X
coordinates, minimum and maximum Y, and minimum
and maximum Z for the zone perimeter. It is
important to give the zone as it is used to
determine many of the rendering parameters. The
default exterior zone is the bounding cube for the
scene as computed by oconv.
materials This variable is used to specify files that,
although they must appear on the oconv command
line, do not affect the actual octree itself.
Keeping the materials in separate files allows
them to be modified without requiring the octree
to be rebuilt (a sometimes costly procedure).
These files should not contain any geometry, and
the -f option must not be given in the "oconv"
variable for this to work.
- This variable is used to specify one or more scene
input files. These files will be given together
with the materials file(s) and any options
specified by the "oconv" variable to oconv to
produce the octree given by the "OCTREE" variable.
If the "scene" variable is not present, then the
octree must already exist in order for rad to
work. Even if this variable is given, oconv will
not be run unless the octree is out of date with
respect to the input files. Note that the order
of files in this variable is important for oconv
to work properly, and files given in later
variable assignments will appear after previous
ones on the oconv command line.
- This variable is used to specify files with
surfaces to be converted into illum sources by
mkillum(1). When this variable is given,
additional octree files will be created to contain
the scene before and after illum source
conversion. These files will be named according
to the (default) value of the OCTREEE variable,
with either a `0' or a `1' appearing just before
the file type suffix (usually ".oct").
- This variable is used for files that, although
they do not appear on the oconv command line,
contain geometric information that is referenced
indirectly by the scene files. If any of these
files is changed, the octree will be rebuilt.
(The raddepend(1) command may be used to find
these dependencies automatically.)
for this zone. Any number of "view" lines may be
given, and each will result in a rendered picture
(unless the -v or -o option is specified). The
value for this variable is an optional identifier
followed by any number of view options (see
rpict(1) for a complete listing). The identifier
is used in file naming and associating a desired
view with the -v command line option. Also, there
are several standard view identifiers defined by
rad. These standard views are specified by strings
of the form "[Xx]?[Yy]?[Zz]?[vlcah]?". (That is,
an optional upper or lower case X followed by an
optional upper or lower case Y followed by an
optional upper or lower case Z followed by an
optional lower case V, L, C, A or H.) The letters
indicate the desired view position, where upper
case X means maximum X, lower case means minimum
and so on. The final letter is the view type,
where `v' is perspective (the default), `l' is
parallel, `c' is a cylindrical panorama, A
perspective view from maximum X, minimum Y would
be "Xy" or "Xyv". A parallel view from maximum Z
would be "Zl". If "ZONE" is an interior zone, the
standard views will be inside the perimeter. If
it is an exterior zone, the standard views will be
outside. Note that the standard views are best
used as starting points, and additional arguments
may be given after the identifier to modify a
standard view to suit a particular model. The
default view is "X" if no views are specified.
- This variable is used to specify a desired view
- The vertical axis for this scene. A negative axis
may be specified with a minus sign (eg. "-Y").
There is no default value for this variable,
although the standard views assume Z is up if no
other axis is specified.
This variable specifies the desired final picture
resolution. If only a single number is given,
this value will be used for both the horizontal
and vertical picture dimensions. If two numbers
are given, the first is the horizontal resolution
and the second is the vertical resolution. If
three numbers are given, the third is taken as the
pixel aspect ratio for the final picture (a real
value). If the pixel aspect ratio is zero, the
exact dimensions given will be those produced.
Otherwise, they will be used as a frame in which
the final image must fit. The default value for
this variable is 512.
PENUMBRAS This is a boolean variable indicating whether or
not penumbras are desired. A value of "TRUE" will
result in penumbras (soft shadows), and a value of
"FALSE" will result in no penumbras (sharp
shadows). True and false may be written in upper
or lower case, and may be abbreviated by a single
letter. Renderings generally proceed much faster
without penumbras. The default value is "F".
- This variable sets the overall rendering quality
desired. It can have one of three values, "LOW",
"MEDIUM" or "HIGH". These may be abbreviated by
their first letter, and may be in upper or lower
case. Most of the rendering options will be
affected by this setting. The default value is
INDIRECT This variable indicates how many diffuse
reflections are important in the general lighting
of this zone. A direct lighting system (eg.
fluorescent troffers recessed in the ceiling)
corresponds to an indirect level of 0. An
indirect lighting system (eg. hanging fluorescents
directed at a reflective ceiling) corresponds to
an indirect level of 1. A diffuse light shelf
reflecting sunlight onto the ceiling would
correspond to an indirect level of 2. The setting
of this variable partially determines how many
interreflections will be calculated. The default
value is 0.
- This is the root name of the output picture
file(s). This name will have appended the view
identifier (or a number if no id was used) and a
".pic" suffix. If a picture corresponding to a
specific view exists and is not out of date with
respect to the given octree, it will not be rerendered.
The default value for this variable is
the root portion of rfile.
- This is the root name of the finished, raw rpict
output file. If specified, rad will rename the
original rpict output file once it is finished and
filtered rather than removing it, which is the
default action. The given root name will be
expanded in the same way as the "PICTURE"
variable, and if the "RAWFILE" and "PICTURE"
variables are identical, then no filtering will
- This is the root name of the raw distance file
produced by the -z option of rpict. To this root
name, an underscore plus the view name plus a
".zbf" suffix will be added. If no "ZFILE" is
specified, none will be produced.
- This is the name of the file where "ambient" or
diffuse interreflection values will be stored by
rpict or rview. Although it is not required, an
ambient file should be given whenever an
interreflection calculation is expected. This
will optimize successive runs and minimize
artifacts. An interreflection calculation will
take place when the "QUALITY" variable is set to
HIGH, or when the "QUALITY" variable is set to
MEDIUM and "INDIRECT" is positive. There is no
default value for this variable.
- This variable specifies the level of visual detail
in this zone, and is used to determine image
sampling rate, among other things. If there are
few surfaces and simple shading, then this should
be set to LOW. For a zone with some furniture it
might be set to MEDIUM. If the space is very
cluttered or contains a lot of geometric detail
and textures, then it should be set to HIGH. The
default value is "M".
This variable tells rad how much light varies over
the surfaces of this zone, and is used to
determine what level of sampling is necessary in
the indirect calculation. For an electric
lighting system with uniform coverage, the value
should be set to LOW. For a space with spot
lighting or a window with sky illumination only,
it might be set to MEDIUM. For a space with
penetrating sunlight casting bright patches in a
few places, it should be set to HIGH. The default
value is "L".
- This is the name of a file in which rad will place
the appropriate rendering options. This file can
later be accessed by rpict or rview in subsequent
manual runs using the at-sign ('@') file insert
option. (Using an "OPTFILE" also reduces the
length of the rendering command, which improves
appearance and may even be necessary on some
systems.) There is no default value for this
- This variable may be used to specify a reporting
interval for batch rendering. Given in minutes,
this value is multiplied by 60 and passed to rpict
with the -t option. If a filename is given after
the interval, it will be used as the error file
for reports and error messages instead of the
standard error. (See the -e option of rpict(1).)
There is no default value for this variable.
- This variable may be used to specify special
options to oconv. See the oconv(1) manual page for
a list of valid options.
- This variable may be used to specify additional
options to mkillum. See the rtrace(1) manual page
for a list of valid options.
- This variable may be used to specify additional
options to rpict or rview. These options will
appear after the options set automatically by rad,
and thus will override the default values.
A minimal input file for rad might look like this:
- This variable may be used to specify additional
options to pfilt. See the pfilt(1) manual page for
# The octree we want to use:
- OCTREE= tutor.oct
- # w/o this line, name would be "sample.oct"
# Our scene input files:
scene= sky.rad outside.rad room.rad srcwindow.rad
# The interior zone cavity:
ZONE= I 0 3 0 2 0 1.75 # default would be scene bounding cube
# The z-axis is up:
- UP= Z
- # no default - would use view spec.
# Our exposure needs one f-stop boost:
Note that we have not specified any views in the file above.
The standard default view "X" would be used if we were to
run rad on this file. If we only want to see what default
values rad would use without actually executing anything, we
can invoke it thus:
- EXPOSURE= +1
- # default is computed ex post facto
rad -n -e sample.rif
This will print the variables we have given as well as
default values rad has assigned for us. Also, we will see
the list of commands that rad would have executed had the -n
option not been present. (Note if the octree, "tutor.oct",
is not present, an error will result as it is needed to
determine some of the opiton settings.)
Different option combinations have specific uses, ie:
- rad -v 0 sample.rif OPT=samp.opt
- # build octree, put
options in "sample.opt"
rad -n -e -s sample.rif > full.rif # make a complete rad
rad -n sample.rif > script.sh # make a script of commands
rad -V -v Zl -n -s sample.rif > plan.vf # make a plan view
- rad -t sample.rif
- # update files after minor change
If we decide that the default values rad has chosen for our
variables are not all appropriate, we can add some more
assignments to the file:
- rad -s sample.rif &
- # execute silently in the
- QUAL= MED
- # default was low
- DET= low
- # default was medium - our space is almost empty
- PEN= True
- # we want to see soft shadows from our window
- VAR= hi
- # daylight can result in fairly harsh lighting
- view= XYa -vv 120
- # let's try a fisheye view
Note the use of abbreviations, and the modification of a
standard view. Now we can invoke rad to take a look at our
scene interactively with rview:
- PICT= tutor
- # our picture name will be "tutor_XYa.pic"
rad -o x11 sample.rif
Rad will run oconv first to create the octree (assuming it
doesn't already exist), then rview with a long list of
options. Let's say that from within rview, we wrote out the
view files "view1.vp" and "view2.vp". We could add these to
"sample.rif" like so:
- view= vw1 -vf view1.vp
- # Our first view
- view= vw2 -vf view2.vp
- # Our second view
To start rview again using vw2 instead of the default, we
- RESOLUTION= 1024
- # Let's go for a higher resolution result
rad -o x11 -v vw2 sample.rif
Once we are happy with the variable settings in our file, we
can run rad in the background to produce one image for each
rad sample.rif REP=5 >& errfile &
This will report progress every five minutes to "errfile".
- Unfinished output of rpict
Incremental building of octrees is not supported as it would
add considerable complexity to rad. Complicated scene builds
should still be left to make(1), which has a robust
mechanism for handling hierarchical dependencies. If make
is used in this fashion, then only the "OCTREE" variable of
rad is needed.
The use of some pfilt options is awkward, since the
"EXPOSURE" variable results in a single pass invocation (the
-1 option of pfilt) and two passes are necessary for certain
effects, such as star patterns. The way around this problem
is to specify a "RAWFILE" that is the same as the "PICTURE"
variable so that no filtering takes place, then call pfilt
manually. This is preferable to leaving out the "EXPOSURE"
variable, since the exposure level is needed to accurately
determine the ambient value for rpict.
The use of upper and lower case naming for the standard
views may be problematic on systems that don't distinguish
case in filenames.
make(1), mkillum(1), oconv(1), pfilt(1), raddpend(1),
ranimate(1), rpict(1), rtrace(1), rview(1), touch(1),
Header and Footer
RAD(1) RADIANCE (3/13/96) RAD(1)
Page 1 (printed 7/17/96)
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