pmblur - Online in the Cloud

PROGRAM:

NAME

pmblur - generate views for camera motion blurring

SYNOPSIS

pmblur speed nsamp v0file v1file

DESCRIPTION

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.)

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.

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).

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.

The -pm option of rpict may be used instead or in combination 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 smaller value should be
given to the rpict -pm option equal to the shutter speed divided by the number of pmblur
views. 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

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:

pmblur .25 8 fr1023.hdr fr1024.hdr | pinterp -B -vf fr1023.hdr -x 640 -y 480 fr1023.hdr
fr1023.zbf fr1024.hdr fr1024.zbf > fr1023b.hdr

Use pmblur online using onworks.net services