RHPICT(1)                                                            RHPICT(1)



NNAAMMEE
       rhpict - render a RADIANCE picture from a holodeck file

SSYYNNOOPPSSIISS
       rrhhppiicctt [ ooppttiioonnss ] hhoollooddeecckk

DDEESSCCRRIIPPTTIIOONN
       _R_h_p_i_c_t  generates  one or more pictures from the RADIANCE holodeck file
       _h_o_l_o_d_e_c_k and sends them to the standard output.  The _-_o option  may  be
       used  to  specify  an alternate output file.  Other options specify the
       viewing parameters and provide some control over the calculation.

       The view as well as some of the other controls  are  shared  in  common
       with  the  _r_p_i_c_t_(_1_) command.  The options that are unique to _r_h_p_i_c_t are
       given first, followed by the more familiar ones.

       --ss        Use the smooth resampling algorithm, which amounts to  linear
                 interpolation between ray samples with additional edge detec-
                 tion along color and object boundaries.  This is the default.

       --rr _r_f     Use  random  resampling,  where  _r_f is a fraction from 0 to 1
                 indicating the desired degree of randomness.  A random  frac-
                 tion of 0 is not the same as smooth resampling, because there
                 is no linear interpolation,  just  Voronoi  regions.   Values
                 greater than 1 produce interesting underwater effects.

       --xx _r_e_s    Set the maximum x resolution to _r_e_s_.

       --yy _r_e_s    Set the maximum y resolution to _r_e_s_.

       --ppaa _r_a_t   Set  the  pixel  aspect  ratio  (height  over  width) to _r_a_t_.
                 Either the x or the y resolution will be reduced so that  the
                 pixels  have  this  ratio  for the specified view.  If _r_a_t is
                 zero, then the x and y resolutions will adhere to  the  given
                 maxima.

       --ppee _e_x_p_v_a_l
                 Set  the  exposure  value  for the output pictures to _e_x_p_v_a_l_.
                 Since filtering is performed by _r_h_p_i_c_t_, there is little sense
                 in  passing  the output through _p_f_i_l_t_(_1_)_, other than changing
                 the exposure.  This option eliminates that need.   The  value
                 may  be  specified  either as a multiplier, or as a number f-
                 stops preceeded by a '+' or '-' character.

       --vvtt_t      Set view type to _t_.  If _t  is  'v',  a  perspective  view  is
                 selected.  If _t is 'l', a parallel view is used.  A cylindri-
                 cal panorma may be selected by setting _t to the  letter  'c'.
                 This view is like a standard perspective vertically, but pro-
                 jected on  a  cylinder  horizontally  (like  a  soupcan's-eye
                 view).   Two fisheye views are provided as well; 'h' yields a
                 hemispherical fisheye view and 'a' results in angular fisheye
                 distortion.   A  hemispherical fisheye is a projection of the
                 hemisphere onto a circle.  The maximum view  angle  for  this
                 type is 180 degrees.  An angular fisheye view is defined such
                 that distance from the center of the image is proportional to
                 the  angle from the central view direction.  An angular fish-
                 eye can display a full 360 degrees.  Note that  there  is  no
                 space  between  the  view  type  option and its single letter
                 argument.

       --vvpp _x _y _z Set the view point to _x _y _z _.  This is the focal point  of  a
                 perspective view or the center of a parallel projection.

       --vvdd _x_d _y_d _z_d
                 Set the view direction vector to _x_d _y_d _z_d _.

       --vvuu _x_d _y_d _z_d
                 Set the view up vector (vertical direction) to _x_d _y_d _z_d _.

       --vvhh _v_a_l   Set  the view horizontal size to _v_a_l_.  For a perspective pro-
                 jection (including fisheye  views),  _v_a_l  is  the  horizontal
                 field  of  view (in degrees).  For a parallel projection, _v_a_l
                 is the view width in world coordinates.

       --vvvv _v_a_l   Set the view vertical size to _v_a_l_.

       --vvoo _v_a_l   Set the view fore clipping plane at a distance  of  _v_a_l  from
                 the  view point.  The plane will be perpendicular to the view
                 direction for perspective and parallel view types.  For fish-
                 eye  view  types,  the  clipping plane is actually a clipping
                 sphere, centered on the view point with radius _v_a_l_.   Objects
                 in front of this imaginary surface will not be visible.  This
                 may be useful for seeing through walls (to get a longer  per-
                 spective from an exterior view point) or for incremental ren-
                 dering.  A value of zero implies no foreground  clipping.   A
                 negative  value  produces  some interesting effects, since it
                 creates an inverted image for objects behind  the  viewpoint.
                 This  possibility  is provided mostly for the purpose of ren-
                 dering stereographic holograms.

       --vvaa _v_a_l   Set the view aft clipping plane at a distance of _v_a_l from the
                 view point.  Like the view fore plane, it will be perpendicu-
                 lar to the view direction for perspective and  parallel  view
                 types.   For  fisheye view types, the clipping plane is actu-
                 ally a clipping sphere,  centered  on  the  view  point  with
                 radius  _v_a_l_.   Objects behind this imaginary surface will not
                 be visible.  A value of zero means no aft  clipping,  and  is
                 the  only  way  to see infinitely distant objects such as the
                 sky.

       --vvss _v_a_l   Set the view shift to _v_a_l_.  This is  the  amount  the  actual
                 image  will  be  shifted  to the right of the specified view.
                 This is option is useful for generating  skewed  perspectives
                 or  rendering an image a piece at a time.  A value of 1 means
                 that the rendered image starts just to the right of the  nor-
                 mal  view.   A  value  of -1 would be to the left.  Larger or
                 fractional values are permitted as well.

       --vvll _v_a_l   Set the view lift to _v_a_l_.  This  is  the  amount  the  actual
                 image  will  be lifted up from the specified view, similar to
                 the _-_v_s option.

       --vvff _f_i_l_e  Get view parameters from _f_i_l_e_, which may be a  picture  or  a
                 file created by rvu (with the "view" command).

       --SS _s_e_q_s_t_a_r_t
                 Instead of generating a single picture based only on the view
                 parameters given on the  command  line,  this  option  causes
                 _r_h_p_i_c_t  to  read view options from the standard input and for
                 each line containing a valid view specification,  generate  a
                 corresponding  picture.   _S_e_q_s_t_a_r_t is a positive integer that
                 will be associated with the first output  frame,  and  incre-
                 mented  for successive output frames.  By default, each frame
                 is concatenated to the output stream, but it is  possible  to
                 change  this  action  using  the _-_o option (described below).
                 Multiple frames may be later extracted from a  single  output
                 stream using the _r_a___r_g_b_e_(_1_) command.

       --oo _f_s_p_e_c  Send  the picture(s) to the file(s) given by _f_s_p_e_c instead of
                 the standard output.  If this option is used  in  combination
                 with  _-_S  and  _f_s_p_e_c  contains an integer field for _p_r_i_n_t_f_(_3_)
                 (eg., "%03d") then the actual output file name  will  include
                 the current frame number.

       --ww        Turn off warning messages.

EEXXAAMMPPLLEE
       rhpict -vp 10 5 3 -vd 1 -.5 0 scene.hdk > scene.pic

       rpict -S 1 -o frame%02d.pic scene.hdk < keyframes.vf

AAUUTTHHOORR
       Greg Ward

SSEEEE AALLSSOO
       getinfo(1),  pfilt(1),  pinterp(1),  printf(3),  ra_rgbe(1),  rholo(1),
       rpict(1), rvu(1)



RADIANCE                            3/10/99                          RHPICT(1)
