PDFBLUR(1)                                                          PDFBLUR(1)



NNAAMMEE
       pdfblur - generate views for depth-of-field blurring

SSYYNNOOPPSSIISS
       ppddffbblluurr aappeerrttuurree ddiissttaannccee nnssaammpp vviieewwffiillee

DDEESSCCRRIIPPTTIIOONN
       _P_d_f_b_l_u_r  takes  the  given _v_i_e_w_f_i_l_e and computes _n_s_a_m_p views based on a
       focus distance of _d_i_s_t_a_n_c_e and an aperture diameter of  _a_p_e_r_t_u_r_e  (both
       in world coordinate units).  When rendered and averaged together, these
       views will result in a picture  with  the  specified  depth  of  field.
       Either  _p_i_n_t_e_r_p_(_1_)  or  _r_p_i_c_t_(_1_)  may  be called to do the actual work.
       (The given _v_i_e_w_f_i_l_e must also be passed on the command line to the cho-
       sen  renderer,  since _p_d_f_b_l_u_r provides supplemental view specifications
       only.)

       For _p_i_n_t_e_r_p_, feed the output of _p_d_f_b_l_u_r to the standard input  of  _p_i_n_-
       _t_e_r_p  and apply the _-_B option to blur views together.  In most cases, a
       single picture with z-buffer is all that is required to get a satisfac-
       tory  result, though the perfectionist may wish to apply three pictures
       arranged in a triangle about the aperature, or alternatively apply  the
       _-_f_f  option  together  with the _-_f_r option of _p_i_n_t_e_r_p_.  (The latter may
       actually work out to be faster, since rendering three views takes three
       times  as  long as a single view, and the _-_f_r option will end up recom-
       puting relatively few pixels by comparison.)

       To use _p_d_f_b_l_u_r with _r_p_i_c_t_, 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  _p_c_o_m_b_(_1_)  program,  using  appropriate scalefactors to
       achieve an average.  Note that using _r_p_i_c_t is MUCH more expensive  than
       using  _p_i_n_t_e_r_p_, 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  _p_i_n_t_e_r_p and _r_p_i_c_t_, the computation time will be proportional
       to the number of views from _p_d_f_b_l_u_r_.  We have  found  a  _n_s_a_m_p  setting
       somewhere  between 5 and 10 to be adequate for most images.  Relatively
       larger values are appropriate for larger aperatures.

EEXXAAMMPPLLEESS
       To use _p_i_n_t_e_r_p to simulate an aperture of 0.5 inches on a lens  focused
       at a distance of 57 inches:

         rpict -vf myview -x 640 -y 480 -z orig.zbf scene.oct > orig.pic
         pdfblur  0.5  57  8  orig.pic | pinterp -B -vf orig.pic -x 640 -y 480
         orig.pic orig.zbf > blurry.pic

       To use _r_p_i_c_t exclusively to do the same:

         pdfblur .5 57 5 myview | rpict -S 1 -vf  myview  -x  640  -y  480  -o
         view%d.pic scene.oct
         pcomb -s .2 view1.pic -s .2 view2.pic -s .2 view3.pic -s .2 view4.pic
         -s .2 view5.pic > blurry.pic

AAUUTTHHOORR
       Greg Ward

BBUUGGSS
       This program really only works with perspective views.

SSEEEE AALLSSOO
       pcomb(1), pinterp(1), pmblur(1), rcalc(1), rpict(1), vwright(1)



RADIANCE                            1/24/96                         PDFBLUR(1)
