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pmblur (1)
NAME
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pmblur - generate views for camera motion blurring |
SYNOPSIS
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pmblur speed nsamp v0file v1file |
DESCRIPTION
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Pmblur takes two viewfiles and generates nsamp
views starting from v0file and moving towards
v1file. When rendered and averaged together, these
views will result in a picture with motion blur due to a
camera changing from v0 to v1 in a relative time unit of 1,
whose shutter is open starting at v0 for speed of
these time units. Either pinterp(1) or
rpict(1) may be called to do the actual work. (The
given v0file must also be passed on the command line
to the chosen renderer, since pmblur provides
supplemental view specifications only.) |
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For pinterp, feed the output of pmblur to the
standard input of pinterp and apply the -B
option to blur views together. In most cases, two pictures
with z-buffers at v0 and v1 will get a satisfactory result,
though the perfectionist may wish to apply the -ff
option together with the -fr option of
pinterp. |
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To use pmblur with rpict, apply the -S
option to indicate a rendering sequence, and set the
-o option with a formatted file name to save multiple
output pictures. When all the renderings are finished,
combine them with the pcomb(1) program, using
appropriate scalefactors to achieve an average. Note that
using rpict is MUCH more expensive than using
pinterp, and it is only recommended if the scene and
application absolutely demand it (e.g. there is prominent
refraction that must be modeled accurately). |
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For both pinterp and rpict, the computation
time will be proportional to the number of views from
pmblur. We have found a nsamp setting
somewhere between 5 and 10 to be adequate for most images.
Relatively larger values are appropriate for faster camera
motion. |
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The -pm option of rpict may be used instead to
blur animated frames, with the added advantage of blurring
reflections and refractions according to their proper
motion. However, this option will result in more noise and
expense than using pmblur with pinterp as a
post-process. If both blurring methods are used, a small
value should be given to the -pm option, on the order
of 0.1 or 0.2. This will be just enough to blur the
boundaries of the ghosts which may appear using
pmblur with a small number of time
samples. |
EXAMPLES
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To use pinterp to simulate motion blur between two
frames of a walk-through animation, where the camera shutter
is open for 1/4 of the interframe distance: |
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pmblur .25 8 fr1023.pic fr1024.pic | pinterp -B -vf
fr1023.pic -x 640 -y 480 fr1023.pic fr1023.zbf fr1024.pic
fr1024.zbf > fr1023b.pic |
AUTHOR
BUGS
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Changes in the view shift and lift vectors or the fore and
aft clipping planes are not blurred. |
SEE ALSO
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