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, 7 months ago) by greg
Branch:	MAIN
CVS Tags:	rad3R5
Log Message:	Added documentation to repository
#	Content
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)