Ubuntu Manpage: ranimate - compute a RADIANCE animation

Provided by: radiance_4R1+20120125-1.1_amd64

NAME

       ranimate - compute a RADIANCE animation

SYNOPSIS

       ranimate [ -s ][ -n ][ -e ][ -w ] ranfile

DESCRIPTION

Ranimate is an executive program that reads the given ranfile and makes appropriate calls to rad(1),
rpict(1), pinterp(1), and/or pfilt(1) to render an animation. Variables in ranfile indicate input files,
process servers (execution hosts), output directories and file names, and various other controls and
options.

Normally, commands are echoed to the standard output as they are executed. The -s option tells ranimate
to do its work silently. The -n option tells ranimate not to take any action (ie. not to actually
execute any commands). The -e option tells ranimate to explicate all variables used for the animation,
including default values not specified in the input file, and print them on the standard output.

The -w option turns off warnings about multiply and misassigned variables.

Normally, ranimate will produce one animation frame for each view given in the specified view file. If
an animation has ended or been killed in an incomplete state, however, ranimate will attempt to pick up
where the earlier process left off. If the process is still running, or was started on another machine,
ranimate will report this information and exit.

Animation variable assignments appear one per line in ranfile. 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, except for
"host", which must have all four. Comments in ranfile start with a pound sign ('#') and proceed to the
end of line.

The animation variables, their interpretations and default values are given below.

DIRECTORY The name of the animation directory. All temporary files generated during the animation will
be placed in this directory, which will be created by ranimate if it does not exist. A file
named "STATUS" will also be created there, and will contain current information about the
animation process. This variable has no default value, and its setting is required.

OCTREE The name of the octree file for a static scene walk-through animation. There is no default
value for this variable, and any setting will be ignored if the ANIMATE variable is also set
(see below).

ANIMATE The scene generation command for a dynamic animation. This command, if given, will be executed
with the frame number as the final argument, and on its standard output it must produce the
complete octree for that frame. Care must be taken that this command does not create any
temporary files that might collide with same-named files created by other animation commands
running in parallel. Also, the command should produce no output to the standard error, unless
there is a fatal condition. (I.e., switch all warnings off; see the BUGS section, below.)
There is no default animation command, and either this variable or the OCTREE variable must be
set.

VIEWFILE This variable names a file from which ranimate may extract the view for each frame in the
animation. This file should contain one valid view per frame, starting with frame 1 on line 1,
regardless of the setting of the START variable. An exception is made for a view file with
only a single view, which is used for every frame of a dynamic scene animation. This variable
is required, and there is no default value.

START The initial frame number in this animation sequence. The minimum value is 1, and if a later
starting frame is given, ranimate assumes that the earlier frames are included in some other
ranfile, which has been previously executed. (See the NEXTANIM variable, below.) The default
value is 1.

END The final frame number in this sequence. The minimum value is equal to the START frame, and
the default value is computed from the number of views in the given VIEWFILE.

EXPOSURE This variable tells ranimate how to adjust the exposure for each frame. As in pfilt, the
exposure setting may be given either as a multiplier or as a number of f-stop adjustments (eg.
+2 or -1.5). Alternatively, a file name may be given, which ranimate will interpret as having
one exposure value per line per frame, beginning with frame 1 at line 1. (See also the
VIEWFILE variable, above.) There is no default value for this variable. If it is not given,
an average level will be computed by pfilt for each frame.

BASENAME The base output file name for the final frames. This string will be passed to the -o and -z
options of rpict, along with appropriate suffixes, and thus should contain a printf(3) style
integer field to distinguish one frame number from another. The final frames will use this
name with a ".hdr" suffix. The default value is the assigned DIRECTORY followed by
"/frame%03d".

host A host to use for command execution. This variable may be assigned a host name, followed by an
optional number of parallel processes, followed by an optional directory (relative to the
user's home directory on that machine), followed by an alternate user name. Multiple host
assignments may appear. It is not advisable to specify more than one process on a single-CPU
host, as this just tends to slow things down. The default value is "localhost", which starts a
single process in the current directory of the local machine.

RIF This variable specifies a rad input file to use as a source of rendering options and other
variable settings. If given, ranimate will execute rad and create an options file to later
pass to rpict or rtrace. Besides prepending the render variable, ranimate will also extract
default settings for the common variables: OCTREE, RESOLUTION, EXPOSURE and pfilt. Following
the file name, overriding variable settings may be given, which will be passed to rad on the
command line. Settings with spaces in them should be enclosed in quotes. The execution of rad
will also update the contents of the octree, if necessary. There is no default value for this
variable.

DISKSPACE Specify the amount of disk space (in megabytes) available on the destination file system for
temporary file storage. Ranimate will coordinate its batch operations based on this amount of
storage, assuming that there is either enough additional space for all the final frames, or
that the given TRANSFER command will move the finished frames to some other location (see
below). The default value is 100 megabytes.

ARCHIVE After each batch rendering is finished and checked for completeness, ranimate will execute the
given command, passing the names of all the original pictures and z-buffer files generated by
rpict. (The command is executed in the destination directory, and file names will be simple.)
Normally, the archive command copies the original files to a tape device or somewhere that they
can be retrieved in the event of failure in the frame interpolation stages. After the archive
command has successfully completed, the original renderings are removed. There is no default
value for this variable, meaning that the original unfiltered frames will simply be removed.
Note that the last one or two rendered frames may not be copied, archived or removed in case
there is a another sequence picking up where this one left off.

TRANSFER The command to transfer the completed animation frames. The shell changes to the destination
directory and appends the names of all the finished frames to this command before it is
executed. Normally, the transfer command does something such as convert the frames to another
format and/or copy them to tape or some other destination device before removing them. The
fieldcomb(1) script may be used to conveniently combine fields into frames for field-based
animations. If this variable is not given, the final frames are left where they are. (See
BASENAME, above.)

RSH The command to use instead of ssh(1) to execute commands remotely on another machine. The
arguments and behavior of this program must be identical to the UNIX ssh command, except that
the -l option will always be used to specify an alternate user name rather than the user@host
convention. The -l option may or may not appear, but the -n option will always be used, and
the expected starting directory will be that of the remote user, just as with ssh.

NEXTANIM This variable specifies the next ranfile to use after this sequence is completed. This offers
a convenient means to continue an animation that requires different control options in
different segments. It is important in this case to correctly set the START and END variables
in each ranfile so that the segments do not overlap frames.

OVERSAMPLE
This variable sets the multiplier of the original image size relative to the final size given
by the RESOLUTION variable. This determines the quality of anti-aliasing in the final frames.
A value of 1 means no anti-aliasing, and a value of 3 produces very good anti-aliasing. The
default value is 2. (A fractional value may be used for previews, causing low resolution
frames with large, blocky pixels to be produced.)

INTERPOLATE
This variable sets the number of frames to interpolate between each rendered frame in a static
scene walk-through. Z-buffers for each rendered frame will be generated by rpict, and pinterp
will be called to perform the actual "tweening." This results in a potentially large savings
in rendering time, but should be used with caution since certain information may be lost or
inaccurate, such as specular highlights and reflections, and objects may even break apart if
too few renderings are used to interpolate too much motion. The default value for this
variable is 0, meaning no interpolation. Interpolation is also switched off if the ANIMATE
variable is specified.

MBLUR This variable specifies the fraction of a frame time that the shutter is simulated as being
open for motion blur. A number of samples may be given as a second argument, which controls
the number of additional frames computed and averaged together by pinterp. If this number is
less than 2, then bluring is performed by rpict only, resulting in greater noise than the
combination of rpict and pinterp used otherwise. (The default value for number of samples is
5.) The default fraction is 0, meaning no motion blurring. This option does not currently
work with the ANIMATE variable, since pinterp only works for static environments.

DBLUR This variable specifies the aperture diameter for depth-of-field blurring, in world units. A
number of samples may be given as a second argument, which controls the number of additional
frames computed and averaged together by pinterp. If this number is less than 2, then blurring
is performed by rpict only, resulting in greater noise than the combination of rpict and
pinterp used otherwise. (The default value for number of samples is 5.) To simulate a
particular camera's aperture, divide the focal length of the lens by the f-number, then convert
to the corresponding world coordinate units. For example, if you wish to simulate a 50mm lens
at f/2.0 in a scene modeled in meters, then you divide 50mm by 2.0 to get 25mm, which
corresponds to an effective aperture of 0.025 meters. The default aperture is 0, meaning no
depth-of-field blurring. This option does not currently work with the ANIMATE variable, since
pinterp only works for static environments.

RTRACE This boolean variable tells ranimate whether or not to employ rtrace during frame interpolation
using the -fr option to pinterp. If set to True, then the same rendering options and static
octree are passed to rtrace as are normally used by rpict. The default value is False. Note
that this variable only applies to static environment walk-throughs (i.e., no ANIMATE command).

RESOLUTION
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 640.

render This variable may be used to specify additional options to rpict or rtrace. These options will
appear after the options set automatically by rad, and thus will override the default values.

pinterp This variable may be used to specify additional options to pinterp, which is used to
interpolate frames for a static scene walk-through. (See the pinterp man page, and the
INTERPOLATE variable.) Do not use this variable to set the pinterp -fr option, but use the
RTRACE setting instead.

pfilt This variable may be used to specify additional options to pfilt. If this variable is given in
the ranfile, then pfilt will always be used. (Normally, pfilt is called only if pinterp is not
needed or automatic exposure is required.) See the pfilt manual page for details.

EXAMPLES

       A minimal input file for ranimate might look like this:

          ::::::::::
          sample.ran
          ::::::::::
          # The rad input file for our static scene:
          RIF= tutor.rif
          # The spool directory:
          DIRECTORY= anim1
          # The view file containing one view per frame:
          VIEWFILE= anim1.vf
          # The amount of temporary disk space available:
          DISKSPACE= 50  # megabytes

       Note  that  most  of  the variables are not set in this file.  If we only want to see what default values
       ranimate would use without actually executing anything, we can invoke it thus:

         ranimate -n -e sample.ran

       This will print the variables we have given as well as default  values  ranimate  has  assigned  for  us.
       Also,  we  will  see  the  list  of commands that ranimate would have executed had the -n option not been
       present.

       Usually, we execute ranimate in the background, redirecting the standard output and standard error  to  a
       file:

         ranimate sample.ran >& sample.err &

       If  we  decide  that the default values ranimate has chosen for our variables are not all appropriate, we
       can add some more assignments to the file:

          host= rays 3 ~greg/obj/tutor ray   # execute as ray on multi-host "rays"
          host= thishost                # execute one copy on this host also
          INTERP= 3                # render every fourth frame
          RES= 1024                # shoot for 1024x resolution
          MBLUR= .25                    # apply camera motion blur
          EXP= anim1.exp                # adjust exposure according to file
          pfilt= -r .9                  # use Gaussian filtering
          ARCHIVE= tar cf /dev/nrtape        # save original renderings to tape

       Note the use of abbreviation for variable names.

FILES

       $(DIRECTORY)/STATUS animation     status     file     $(DIRECTORY)/*      other      temporary      files
       $(BASENAME).hdr          final animation frames

AUTHOR

       Greg Ward

BUGS

Due to the difficulty of controlling processes on multiple execution hosts, the -n option of ranimate is
not useful in the same way as rad for generating a script of executable commands to render the sequence.
It may give an idea of the sequence of events, but certain temporary files and so forth will not be in
the correct state if the user attempts to create a separate batch script.

If multiple processors are available on a given host and the RTRACE variable is set to True, then the -PP
option of rtrace should be employed, but it is not. There is no easy way around this problem, but it has
only minor consequences in most cases. (The -PP option is used for rpict, however.)

The current implementation of the remote shell does not return the exit status of the remote process,
which makes it difficult to determine for sure if there has been a serious error or not. Because of
this, ranimate normally turns off warnings on all rendering processes, and takes any output to standard
error from a remote command as a sign that a fatal error has occurred. (This also precludes the use of
the -t option to report rendering progress.) If the error was caused by a process server going down, the
server is removed from the active list and frame recovery takes place. Otherwise, ranimate quits at that
point in the animation.

The current execution environment, in particular the RAYPATH variable, will not be passed during remote
command execution, so it is necessary to set whatever variables are important in the remote startup
script (e.g., ".cshrc" for the C-shell). This requirement may be circumvented by substituting the on(1)
command for ssh(1) using the RSH control variable, or by writing a custom remote execution script.

If a different remote user name is used, ranimate first attempts to change to the original user's
directory with a command of the form cd uname . This works under csh(1), but may fail under other
shells such as sh(1).

If multiple hosts with different floating point formats are used, pinterp will fail because the Z-buffer
files will be inconsistent. (Recall that pinterp is called if INTERPOLATE > 0 and/or MBLUR is
assigned.) Since most modern machines use IEEE floating point, this is not usually a problem, but it is
something to keep in mind.