POV-Ray

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Revision as of 13:16, 21 April 2009 by Neteler (talk | contribs) (+Script to generate camera parameters for Povray)

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About

POV-Ray is the Persistence of Vision Raytracer. It makes pretty 3D maps.

GRASS has r.out.pov and v.out.pov modules for outputting maps to the software.

Tips and tutorials

Script to generate camera parameters for Povray

This script is an easy way to get the camera parameters for povray. Use to personalize one of the control files downloadable above from M Neteler's old Web page:

 #!/bin/sh
 #
 # generate useful parameters for POVRAY control file
 # Markus Neteler 7/2003
 # $Date: 2005-02-10 17:56:18 +0100 (Do, 10 Feb 2005) $
 
 if  [ -z "$GISBASE" ] ; then
  echo "You must be in GRASS GIS to run this program." >&2
  exit 1
 fi
 
 if [ $# -lt 1 -o "$1" = "help" -o "$1" = "-h" -o "$1" = "--help" ] ; then
  echo "Script to generate POVRAY control file coordinates"
  echo "Usage:"
  echo "     r.out.povscript dtm "
  echo ""
  echo "The script reports values according to the current region"
  exit 1
 fi
 
 DEM=$1
 
 # get n,s,e,w
 eval `g.region -g`
 # get extents
 eval `g.region -ge`
 # get centers
 eval `g.region -gc`
 
 echo ""
 echo "                                n:$n"
 echo "                        +-----------------+"
 echo "                        |                 |"
 echo "    w:$w     |                 |  e:$e"  
 echo "                        |                 |"
 echo "                        |        c  <-*C  |    c: center ($center_easting $center_northing)"
 echo "                        |                 |    C: camera (pos: x 75%, y 50%)"
 echo "                        |                 |"
 echo "                        |                 | N-S extent: $ns_extent"
 echo "                        +-----------------+"
 echo "                                s:$s"
 echo "                 <- E-W extent: $ew_extent ->"
 echo ""
 echo "Povray control file parameters:"
 
 CAM1="`echo $e $w $ew_extent | awk '{printf "%f", (($1 + $2)/2 + ($3/4))}'`"
 CAM3="`echo $n $s | awk '{printf "%f", ($1 + $2)/2}'`"
 
 DEMZVAL="`r.what $DEM east_north=$CAM1,$CAM3 | cut -d'|' -f4`"
 DEMZVALHIGH="`echo $DEMZVAL | awk '{printf "%f", $1 + 700}'`"
 
 LOOK1="`echo $e $w | awk '{printf "%f", ($1 + $2)/2}'`"
 LOOK3="`echo $n $s | awk '{printf "%f", ($1 + $2)/2}'`"
 
 SCALE1=$cols
 SCALE3=$rows
 
 SUN1=$CAM1
 SUN3="`echo $s $ns_extent | awk '{printf "%f", ($1 - $2)}'`"
 
 echo "light_source:  < $SUN1, 7000, $SUN3 >"
 echo "Camera:        < $CAM1, $DEMZVALHIGH, $CAM3 >"
 echo "Look at:       < $LOOK1, $DEMZVAL, $LOOK3 >"
 echo "DEM scale:     < $ew_extent, 65535, $ns_extent >"
 echo "DEM translate: < $w, 0, $s >"


See also