Radiance pmblur program

PMBLUR(1)                                                            PMBLUR(1)

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 mul-
       tiple 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)

RADIANCE                            3/3/98                           PMBLUR(1)