man/man1/ranimate.1

.\" RCSid "$Id"
.TH RANIMATE 1 6/24/98 RADIANCE
.SH NAME
ranimate - compute a RADIANCE animation
.SH SYNOPSIS
.B ranimate
[
.B \-s
][
.B \-n
][
.B \-e
][
.B \-w
]
.B ranfile
.SH DESCRIPTION
.I Ranimate
is an executive program that reads the given
.I ranfile
and makes appropriate calls to
.I rad(1),
.I rpict(1),
.I pinterp(1),
and/or
.I pfilt(1)
to render an animation.
Variables in
.I ranfile
indicate input files, process servers (execution hosts), output
directories and file names, and various other controls and options.
.PP
Normally, commands are echoed to the standard output as they are
executed.
The
.I \-s
option tells
.I ranimate
to do its work silently.
The
.I \-n
option tells
.I ranimate
not to take any action (ie. not to actually execute any commands).
The
.I \-e
option tells
.I 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.
.PP
The
.I \-w
option turns off warnings about multiply and misassigned variables.
.PP
Normally,
.I 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,
.I ranimate
will attempt to pick up where the earlier process left off.
If the process is still running, or was started on another machine,
.I ranimate
will report this information and exit.
.PP
Animation variable assignments appear one per line in
.I 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
.I ranfile
start with a pound sign ('#') and proceed to the end of line.
.PP
The animation variables, their interpretations and default values
are given below.
.TP 10n
.BR 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
.I 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.
.TP
.BR 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
.I ANIMATE
variable is also set (see below).
.TP
.BR 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.)\0
There is no default animation command, and either this variable or the
.I OCTREE
variable must be set.
.TP
.BR VIEWFILE
This variable names a file from which
.I 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
.I 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.
.TP
.BR START
The initial frame number in this animation sequence.
The minimum value is 1, and if a later starting frame is given,
.I ranimate
assumes that the earlier frames are included in some other
.I ranfile,
which has been previously executed.
(See the
.I NEXTANIM
variable, below.)\0
The default value is 1.
.TP
.BR END
The final frame number in this sequence.
The minimum value is equal to the
.I START
frame,
and the default value is computed from the number of views in the
given
.I VIEWFILE.
.TP
.BR EXPOSURE
This variable tells
.I ranimate
how to adjust the exposure for each frame.
As in
.I 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
.I ranimate
will interpret as having one exposure value per line per frame,
beginning with frame 1 at line 1.
(See also the
.I VIEWFILE
variable, above.)\0
There is no default value for this variable.
If it is not given, an average level will be computed by
.I pfilt
for each frame.
.TP
.BR BASENAME
The base output file name for the final frames.
This string will be passed to the
.I \-o
and
.I \-z
options of rpict, along with appropriate suffixes,
and thus should contain a
.I printf(3)
style integer field to distinguish one frame number from another.
The final frames will use this name with a ".pic" suffix.
The default value is the assigned
.I DIRECTORY
followed by "/frame%03d".
.TP
.BR 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
.I 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.
.TP
.BR RIF
This variable specifies a
.I rad
input file to use as a source of rendering options and other
variable settings.
If given,
.I ranimate
will execute
.I rad
and create an options file to later pass to
.I rpict
or
.I rtrace.
Besides prepending the
.I render
variable,
.I ranimate
will also extract default settings for the common variables:
.I OCTREE,
.I RESOLUTION,
.I EXPOSURE
and
.I pfilt.
Following the file name, overriding variable settings may be given,
which will be passed to
.I rad
on the command line.
Settings with spaces in them should be enclosed in quotes.
The execution of
.I rad
will also update the contents of the octree, if necessary.
There is no default value for this variable.
.TP
.BR DISKSPACE
Specify the amount of disk space (in megabytes) available on the
destination file system for temporary file storage.
.I 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
.I TRANSFER
command will move the finished frames to some other location (see
below).
The default value is 100 megabytes.
.TP
.BR ARCHIVE
After each batch rendering is finished and checked for completeness,
.I ranimate
will execute the given command, passing the names of all the
original pictures and z-buffer files generated by
.I rpict.
(The command is executed in the destination directory, and file names
will be simple.)\0
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.
.TP
.BR 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.
If this variable is not given, the final frames are left where they
are.
(See
.I BASENAME,
above.)\0
.TP
.BR RSH
The command to use instead of
.I rsh(1)
to execute commands remotely on another machine.
The arguments and behavior of this program must be identical to the UNIX
.I rsh
command, except that the
.I -l
option will always be used to specify an alternate user name rather than the
.I "user@host"
convention.
Th
.I -l
option may or may not appear, but the
.I -n
option will always be used, and the expected starting directory will
be that of the remote user, just as with
.I rsh.
.TP
.BR NEXTANIM
This variable specifies the next
.I 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
.I START
and
.I END
variables in each
.I ranfile
so that the segments do not overlap frames.
.TP
.BR OVERSAMPLE
This variable sets the multiplier of the original image size
relative to the final size given by the
.I 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.)\0
.TP
.BR 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
.I rpict,
and
.I 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
.I ANIMATE
variable is specified.
.TP
.BR 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
.I pinterp.
If this number is less than 2, then bluring is performed by
.I rpict
only, resulting in greater noise than the combination of
.I rpict
and
.I pinterp used otherwise.
(The default value for number of samples is 5.)\0
The
.I pmblur(1)
command is used to generate the given number of additional views for
.I pinterp
to average together.
The default value is 0, meaning no motion blurring.
This option does not currently work with the
.I ANIMATE
variable, since pinterp only works for static environments.
.TP
.BR RTRACE
This boolean variable tells
.I ranimate
whether or not to employ
.I rtrace
during frame interpolation using the
.I \-fr
option to
.I pinterp.
If set to True, then the same rendering options and static octree
are passed to
.I rtrace
as are normally used by
.I rpict.
The default value is False.
Note that this variable only applies to static environment
walk-throughs (i.e., no
.I ANIMATE
command).
.TP
.BR 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.
.TP
.BR render
This variable may be used to specify additional options to
.I rpict
or
.I rtrace.
These options will appear after the options set automatically by
.I rad,
and thus will override the default values.
.TP
.BR pinterp
This variable may be used to specify additional options to
.I pinterp,
which is used to interpolate frames for a static scene walk-through.
(See the
.I pinterp
man page, and the
.I INTERPOLATE
variable.)\0
Do not use this variable to set the
.I pinterp
.I \-fr
option, but use the
.I RTRACE
setting instead.
.TP
.BR pfilt
This variable may be used to specify additional options to
.I pfilt.
If this variable is given in the
.I ranfile,
then
.I pfilt
will always be used.
(Normally,
.I pfilt
is called only if
.I pinterp
is not needed or automatic exposure is required.)\0
See the
.I pfilt
manual page for details.
.SH EXAMPLES
A minimal input file for
.I ranimate
might look like this:
.IP "" .3i
.nf
::::::::::
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
.fi
.PP
Note that most of the variables are not set in this file.
If we only want to see what default values
.I ranimate
would use without actually executing anything, we can invoke it
thus:
.IP "" .2i
ranimate -n -e sample.ran
.PP
This will print the variables we have given as well as default
values
.I ranimate
has assigned for us.
Also, we will see the list of commands that
.I ranimate
would have executed had the
.I \-n
option not been present.
.PP
Usually, we execute
.I ranimate
in the background, redirecting the standard output and standard
error to a file:
.IP "" .2i
ranimate sample.ran >& sample.err &
.PP
If we decide that the default values
.I ranimate
has chosen for our variables are not all appropriate, we can add
some more assignments to the file:
.IP "" .3i
.nf
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
.fi
.PP
Note the use of abbreviation for variable names.
.SH FILES
$(DIRECTORY)/STATUS     animation status file
$(DIRECTORY)/*          other temporary files
$(BASENAME).pic         final animation frames
.SH AUTHOR
Greg Ward
.SH BUGS
Due to the difficulty of controlling processes on multiple execution
hosts, the
.I \-n
option of
.I ranimate
is not useful in the same way as
.I 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.
.PP
If multiple processors are available on a given host and the
.I RTRACE
variable is set to True, then the
.I \-PP
option of
.I 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
.I \-PP
option is used for
.I rpict,
however.)\0
.I
.PP
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,
.I 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
.I \-t
option to report rendering progress.)\0
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,
.I ranimate
quits at that point in the animation.
.PP
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
.I on(1)
command for
.I rsh(1)
using the
.I RSH
control variable, or by writing a custom remote execution script.
.PP
If a different remote user name is used,
.I ranimate
first attempts to change to the original user's directory with a
command of the form
.I "cd \~uname".
This works under
.I csh(1),
but may fail under other shells such as
.I sh(1).
.PP
If multiple hosts with different floating point formats are used,
.I pinterp
will fail because the Z-buffer files will be inconsistent.
(Recall that
.I pinterp
is called if INTERPOLATE > 0 and/or MBLUR is assigned.)\0
Since most modern machines use IEEE floating point, this is not
usually a problem, but it is something to keep in mind.
.SH "SEE ALSO"
pfilt(1), pinterp(1), pmblur(1), rad(1),
ranimove(1), rpict(1), rsh(1), rtrace(1)
Revision:	1.1
Committed:	Tue Mar 11 19:20:21 2003 UTC (22 years, 8 months ago) by greg
Branch:	MAIN
CVS Tags:	rad3R5
Log Message:	Added documentation to repository
#	User	Rev	Content
1	greg	1.1	.\" RCSid "$Id"
2			.TH RANIMATE 1 6/24/98 RADIANCE
3			.SH NAME
4			ranimate - compute a RADIANCE animation
5			.SH SYNOPSIS
6			.B ranimate
7			[
8			.B \-s
9			][
10			.B \-n
11			][
12			.B \-e
13			][
14			.B \-w
15			]
16			.B ranfile
17			.SH DESCRIPTION
18			.I Ranimate
19			is an executive program that reads the given
20			.I ranfile
21			and makes appropriate calls to
22			.I rad(1),
23			.I rpict(1),
24			.I pinterp(1),
25			and/or
26			.I pfilt(1)
27			to render an animation.
28			Variables in
29			.I ranfile
30			indicate input files, process servers (execution hosts), output
31			directories and file names, and various other controls and options.
32			.PP
33			Normally, commands are echoed to the standard output as they are
34			executed.
35			The
36			.I \-s
37			option tells
38			.I ranimate
39			to do its work silently.
40			The
41			.I \-n
42			option tells
43			.I ranimate
44			not to take any action (ie. not to actually execute any commands).
45			The
46			.I \-e
47			option tells
48			.I ranimate
49			to explicate all variables used for the animation, including
50			default values not specified in the input file, and print them on
51			the standard output.
52			.PP
53			The
54			.I \-w
55			option turns off warnings about multiply and misassigned variables.
56			.PP
57			Normally,
58			.I ranimate
59			will produce one animation frame for each view given in the specified
60			view file.
61			If an animation has ended or been killed in an incomplete state, however,
62			.I ranimate
63			will attempt to pick up where the earlier process left off.
64			If the process is still running, or was started on another machine,
65			.I ranimate
66			will report this information and exit.
67			.PP
68			Animation variable assignments appear one per line in
69			.I ranfile.
70			The name of the variable is followed by an equals sign
71			('=') and its value(s).
72			The end of line may be escaped with a backslash ('\\'), though it is
73			not usually necessary since additional variable values may be given
74			in multiple assignments.
75			Variables that should have only one value are given in upper case.
76			Variables that may have multiple values are given in lower case.
77			Variables may be abbreviated by their first three letters, except
78			for "host", which must have all four.
79			Comments in
80			.I ranfile
81			start with a pound sign ('#') and proceed to the end of line.
82			.PP
83			The animation variables, their interpretations and default values
84			are given below.
85			.TP 10n
86			.BR DIRECTORY
87			The name of the animation directory.
88			All temporary files generated during the animation will be placed in
89			this directory, which will be created by
90			.I ranimate
91			if it does not exist.
92			A file named "STATUS" will also be created there, and will contain current
93			information about the animation process.
94			This variable has no default value, and its setting is required.
95			.TP
96			.BR OCTREE
97			The name of the octree file for a static scene walk-through
98			animation.
99			There is no default value for this variable, and any
100			setting will be ignored if the
101			.I ANIMATE
102			variable is also set (see below).
103			.TP
104			.BR ANIMATE
105			The scene generation command for a dynamic animation.
106			This command, if given, will be executed with the frame number as the
107			final argument, and on its standard output it must produce
108			the complete octree for that frame.
109			Care must be taken that this command does not create any temporary files
110			that might collide with same-named files created by other
111			animation commands running in parallel.
112			Also, the command should produce no output to the standard error, unless
113			there is a fatal condition.
114			(I.e., switch all warnings off;
115			see the BUGS section, below.)\0
116			There is no default animation command, and either this variable or the
117			.I OCTREE
118			variable must be set.
119			.TP
120			.BR VIEWFILE
121			This variable names a file from which
122			.I ranimate
123			may extract the view for each frame in the animation.
124			This file should contain one valid view per frame, starting with
125			frame 1 on line 1, regardless of the setting of the
126			.I START
127			variable.
128			An exception is made for a view file with only a single view, which
129			is used for every frame of a dynamic scene animation.
130			This variable is required, and there is no default value.
131			.TP
132			.BR START
133			The initial frame number in this animation sequence.
134			The minimum value is 1, and if a later starting frame is given,
135			.I ranimate
136			assumes that the earlier frames are included in some other
137			.I ranfile,
138			which has been previously executed.
139			(See the
140			.I NEXTANIM
141			variable, below.)\0
142			The default value is 1.
143			.TP
144			.BR END
145			The final frame number in this sequence.
146			The minimum value is equal to the
147			.I START
148			frame,
149			and the default value is computed from the number of views in the
150			given
151			.I VIEWFILE.
152			.TP
153			.BR EXPOSURE
154			This variable tells
155			.I ranimate
156			how to adjust the exposure for each frame.
157			As in
158			.I pfilt,
159			the exposure setting may be given either as a multiplier or as a
160			number of f-stop adjustments (eg. +2 or -1.5).
161			Alternatively, a file name may be given, which
162			.I ranimate
163			will interpret as having one exposure value per line per frame,
164			beginning with frame 1 at line 1.
165			(See also the
166			.I VIEWFILE
167			variable, above.)\0
168			There is no default value for this variable.
169			If it is not given, an average level will be computed by
170			.I pfilt
171			for each frame.
172			.TP
173			.BR BASENAME
174			The base output file name for the final frames.
175			This string will be passed to the
176			.I \-o
177			and
178			.I \-z
179			options of rpict, along with appropriate suffixes,
180			and thus should contain a
181			.I printf(3)
182			style integer field to distinguish one frame number from another.
183			The final frames will use this name with a ".pic" suffix.
184			The default value is the assigned
185			.I DIRECTORY
186			followed by "/frame%03d".
187			.TP
188			.BR host
189			A host to use for command execution.
190			This variable may be assigned a host name, followed by an optional
191			number of parallel processes, followed by an optional
192			directory (relative to the user's home directory on that machine),
193			followed by an alternate user name.
194			Multiple
195			.I host
196			assignments may appear.
197			It is not advisable to specify more than one process on a single-CPU
198			host, as this just tends to slow things down.
199			The default value is "localhost", which starts a single process in
200			the current directory of the local machine.
201			.TP
202			.BR RIF
203			This variable specifies a
204			.I rad
205			input file to use as a source of rendering options and other
206			variable settings.
207			If given,
208			.I ranimate
209			will execute
210			.I rad
211			and create an options file to later pass to
212			.I rpict
213			or
214			.I rtrace.
215			Besides prepending the
216			.I render
217			variable,
218			.I ranimate
219			will also extract default settings for the common variables:
220			.I OCTREE,
221			.I RESOLUTION,
222			.I EXPOSURE
223			and
224			.I pfilt.
225			Following the file name, overriding variable settings may be given,
226			which will be passed to
227			.I rad
228			on the command line.
229			Settings with spaces in them should be enclosed in quotes.
230			The execution of
231			.I rad
232			will also update the contents of the octree, if necessary.
233			There is no default value for this variable.
234			.TP
235			.BR DISKSPACE
236			Specify the amount of disk space (in megabytes) available on the
237			destination file system for temporary file storage.
238			.I Ranimate
239			will coordinate its batch operations based on this amount of storage,
240			assuming that there is either enough additional space for all the
241			final frames, or that the given
242			.I TRANSFER
243			command will move the finished frames to some other location (see
244			below).
245			The default value is 100 megabytes.
246			.TP
247			.BR ARCHIVE
248			After each batch rendering is finished and checked for completeness,
249			.I ranimate
250			will execute the given command, passing the names of all the
251			original pictures and z-buffer files generated by
252			.I rpict.
253			(The command is executed in the destination directory, and file names
254			will be simple.)\0
255			Normally, the archive command copies the original files to a tape device
256			or somewhere that they can be retrieved in the event of failure in
257			the frame interpolation stages.
258			After the archive command has successfully completed, the original
259			renderings are removed.
260			There is no default value for this variable, meaning that the
261			original unfiltered frames will simply be removed.
262			Note that the last one or two rendered frames may not be copied, archived
263			or removed in case there is a another sequence picking up where this
264			one left off.
265			.TP
266			.BR TRANSFER
267			The command to transfer the completed animation frames.
268			The shell changes to the destination directory and appends
269			the names of all the finished frames to this command
270			before it is executed.
271			Normally, the transfer command does something such as convert the
272			frames to another format and/or copy them to tape or some other
273			destination device before removing them.
274			If this variable is not given, the final frames are left where they
275			are.
276			(See
277			.I BASENAME,
278			above.)\0
279			.TP
280			.BR RSH
281			The command to use instead of
282			.I rsh(1)
283			to execute commands remotely on another machine.
284			The arguments and behavior of this program must be identical to the UNIX
285			.I rsh
286			command, except that the
287			.I -l
288			option will always be used to specify an alternate user name rather than the
289			.I "user@host"
290			convention.
291			Th
292			.I -l
293			option may or may not appear, but the
294			.I -n
295			option will always be used, and the expected starting directory will
296			be that of the remote user, just as with
297			.I rsh.
298			.TP
299			.BR NEXTANIM
300			This variable specifies the next
301			.I ranfile
302			to use after this sequence is completed.
303			This offers a convenient means to continue an animation that
304			requires different control options in different segments.
305			It is important in this case to correctly set the
306			.I START
307			and
308			.I END
309			variables in each
310			.I ranfile
311			so that the segments do not overlap frames.
312			.TP
313			.BR OVERSAMPLE
314			This variable sets the multiplier of the original image size
315			relative to the final size given by the
316			.I RESOLUTION
317			variable.
318			This determines the quality of anti-aliasing in the final frames.
319			A value of 1 means no anti-aliasing, and a value of 3 produces very
320			good anti-aliasing.
321			The default value is 2.
322			(A fractional value may be used for previews, causing low
323			resolution frames with large, blocky pixels to be produced.)\0
324			.TP
325			.BR INTERPOLATE
326			This variable sets the number of frames to interpolate between each
327			rendered frame in a static scene walk-through.
328			Z-buffers for each rendered frame will be generated by
329			.I rpict,
330			and
331			.I pinterp
332			will be called to perform the actual "tweening."
333			This results in a potentially large savings in rendering time, but
334			should be used with caution since certain information may be lost or
335			inaccurate, such as specular highlights and reflections, and objects
336			may even break apart if too few renderings are used to interpolate
337			too much motion.
338			The default value for this variable is 0, meaning no interpolation.
339			Interpolation is also switched off if the
340			.I ANIMATE
341			variable is specified.
342			.TP
343			.BR MBLUR
344			This variable specifies the fraction of a frame time that the shutter
345			is simulated as being open for motion blur.
346			A number of samples may be given as a second argument, which
347			controls the number of additional frames computed and averaged
348			together by
349			.I pinterp.
350			If this number is less than 2, then bluring is performed by
351			.I rpict
352			only, resulting in greater noise than the combination of
353			.I rpict
354			and
355			.I pinterp used otherwise.
356			(The default value for number of samples is 5.)\0
357			The
358			.I pmblur(1)
359			command is used to generate the given number of additional views for
360			.I pinterp
361			to average together.
362			The default value is 0, meaning no motion blurring.
363			This option does not currently work with the
364			.I ANIMATE
365			variable, since pinterp only works for static environments.
366			.TP
367			.BR RTRACE
368			This boolean variable tells
369			.I ranimate
370			whether or not to employ
371			.I rtrace
372			during frame interpolation using the
373			.I \-fr
374			option to
375			.I pinterp.
376			If set to True, then the same rendering options and static octree
377			are passed to
378			.I rtrace
379			as are normally used by
380			.I rpict.
381			The default value is False.
382			Note that this variable only applies to static environment
383			walk-throughs (i.e., no
384			.I ANIMATE
385			command).
386			.TP
387			.BR RESOLUTION
388			This variable specifies the desired final picture resolution.
389			If only a single number is given, this value will be used for both
390			the horizontal and vertical picture dimensions.
391			If two numbers are given, the first is the horizontal resolution and
392			the second is the vertical resolution.
393			If three numbers are given, the third is taken as the pixel aspect
394			ratio for the final picture (a real value).
395			If the pixel aspect ratio is zero, the exact dimensions given will
396			be those produced.
397			Otherwise, they will be used as a frame in which the final image
398			must fit.
399			The default value for this variable is 640.
400			.TP
401			.BR render
402			This variable may be used to specify additional options to
403			.I rpict
404			or
405			.I rtrace.
406			These options will appear after the options set automatically by
407			.I rad,
408			and thus will override the default values.
409			.TP
410			.BR pinterp
411			This variable may be used to specify additional options to
412			.I pinterp,
413			which is used to interpolate frames for a static scene walk-through.
414			(See the
415			.I pinterp
416			man page, and the
417			.I INTERPOLATE
418			variable.)\0
419			Do not use this variable to set the
420			.I pinterp
421			.I \-fr
422			option, but use the
423			.I RTRACE
424			setting instead.
425			.TP
426			.BR pfilt
427			This variable may be used to specify additional options to
428			.I pfilt.
429			If this variable is given in the
430			.I ranfile,
431			then
432			.I pfilt
433			will always be used.
434			(Normally,
435			.I pfilt
436			is called only if
437			.I pinterp
438			is not needed or automatic exposure is required.)\0
439			See the
440			.I pfilt
441			manual page for details.
442			.SH EXAMPLES
443			A minimal input file for
444			.I ranimate
445			might look like this:
446			.IP "" .3i
447			.nf
448			::::::::::
449			sample.ran
450			::::::::::
451			# The rad input file for our static scene:
452			RIF= tutor.rif
453			# The spool directory:
454			DIRECTORY= anim1
455			# The view file containing one view per frame:
456			VIEWFILE= anim1.vf
457			# The amount of temporary disk space available:
458			DISKSPACE= 50 # megabytes
459			.fi
460			.PP
461			Note that most of the variables are not set in this file.
462			If we only want to see what default values
463			.I ranimate
464			would use without actually executing anything, we can invoke it
465			thus:
466			.IP "" .2i
467			ranimate -n -e sample.ran
468			.PP
469			This will print the variables we have given as well as default
470			values
471			.I ranimate
472			has assigned for us.
473			Also, we will see the list of commands that
474			.I ranimate
475			would have executed had the
476			.I \-n
477			option not been present.
478			.PP
479			Usually, we execute
480			.I ranimate
481			in the background, redirecting the standard output and standard
482			error to a file:
483			.IP "" .2i
484			ranimate sample.ran >& sample.err &
485			.PP
486			If we decide that the default values
487			.I ranimate
488			has chosen for our variables are not all appropriate, we can add
489			some more assignments to the file:
490			.IP "" .3i
491			.nf
492			host= rays 3 ~greg/obj/tutor ray # execute as ray on multi-host "rays"
493			host= thishost # execute one copy on this host also
494			INTERP= 3 # render every fourth frame
495			RES= 1024 # shoot for 1024x resolution
496			MBLUR= .25 # apply camera motion blur
497			EXP= anim1.exp # adjust exposure according to file
498			pfilt= -r .9 # use Gaussian filtering
499			ARCHIVE= tar cf /dev/nrtape # save original renderings to tape
500			.fi
501			.PP
502			Note the use of abbreviation for variable names.
503			.SH FILES
504			$(DIRECTORY)/STATUS animation status file
505			$(DIRECTORY)/* other temporary files
506			$(BASENAME).pic final animation frames
507			.SH AUTHOR
508			Greg Ward
509			.SH BUGS
510			Due to the difficulty of controlling processes on multiple execution
511			hosts, the
512			.I \-n
513			option of
514			.I ranimate
515			is not useful in the same way as
516			.I rad
517			for generating a script of executable commands to render the
518			sequence.
519			It may give an idea of the sequence of events, but certain temporary
520			files and so forth will not be in the correct state if the user
521			attempts to create a separate batch script.
522			.PP
523			If multiple processors are available on a given host and the
524			.I RTRACE
525			variable is set to True, then the
526			.I \-PP
527			option of
528			.I rtrace
529			should be employed, but it is not.
530			There is no easy way around this problem, but it has only minor
531			consequences in most cases.
532			(The
533			.I \-PP
534			option is used for
535			.I rpict,
536			however.)\0
537			.I
538			.PP
539			The current implementation of the remote shell does not return the
540			exit status of the remote process, which makes it difficult to
541			determine for sure if there has been a serious error or not.
542			Because of this,
543			.I ranimate
544			normally turns off warnings on all rendering processes, and takes
545			any output to standard error from a remote command as a sign that a
546			fatal error has occurred.
547			(This also precludes the use of the
548			.I \-t
549			option to report rendering progress.)\0
550			If the error was caused by a process server going down, the server
551			is removed from the active list and frame recovery takes place.
552			Otherwise,
553			.I ranimate
554			quits at that point in the animation.
555			.PP
556			The current execution environment, in particular the RAYPATH variable,
557			will not be passed during remote command execution, so it is necessary
558			to set whatever variables are important in the remote startup script
559			(e.g., ".cshrc" for the C-shell).
560			This requirement may be circumvented by substituting the
561			.I on(1)
562			command for
563			.I rsh(1)
564			using the
565			.I RSH
566			control variable, or by writing a custom remote execution script.
567			.PP
568			If a different remote user name is used,
569			.I ranimate
570			first attempts to change to the original user's directory with a
571			command of the form
572			.I "cd \~uname".
573			This works under
574			.I csh(1),
575			but may fail under other shells such as
576			.I sh(1).
577			.PP
578			If multiple hosts with different floating point formats are used,
579			.I pinterp
580			will fail because the Z-buffer files will be inconsistent.
581			(Recall that
582			.I pinterp
583			is called if INTERPOLATE > 0 and/or MBLUR is assigned.)\0
584			Since most modern machines use IEEE floating point, this is not
585			usually a problem, but it is something to keep in mind.
586			.SH "SEE ALSO"
587			pfilt(1), pinterp(1), pmblur(1), rad(1),
588			ranimove(1), rpict(1), rsh(1), rtrace(1)