xenial (1) pmblur.1.gz

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

AUTHOR

       Greg Ward

BUGS

       Changes in the view shift and lift vectors or the fore and aft clipping planes are not blurred.

SEE ALSO

       pcomb(1), pdfblur(1), pinterp(1), pmdblur(1), rcalc(1), rpict(1), vwright(1)