Provided by: grass-doc_7.6.0-1_all bug

NAME

       r3.out.vtk  - Converts 3D raster maps into the VTK-ASCII format.

KEYWORDS

       raster3d, export, voxel, VTK

SYNOPSIS

       r3.out.vtk
       r3.out.vtk --help
       r3.out.vtk     [-psmocl]      [input=name[,name,...]]      [output=name]      [null=float]
       [top=string]   [bottom=string]   [rgbmaps=name[,name,...]]    [vectormaps=name[,name,...]]
       [zscale=float]    [precision=integer]    [--overwrite]   [--help]   [--verbose]  [--quiet]
       [--ui]

   Flags:
       -p
           Create VTK pointdata instead of VTK celldata (celldata is default)

       -s
           Create 3D elevation output with a top and a  bottom  surface,  both  raster  maps  are
           required.

       -m
           Use 3D raster mask (if exists) with input maps

       -o
           Scale factor affects the origin

       -c
           Correct the coordinates to match the VTK-OpenGL precision

       -l
           Do not convert the top-bottom resolution in case of lat long projection to meters

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       input=name[,name,...]
           3D raster map(s) to be converted to VTK-ASCII data format

       output=name
           Name for VTK-ASCII output file

       null=float
           Float value to represent no data cell/points
           Default: -99999.99

       top=string
           Top surface 2D raster map

       bottom=string
           Bottom surface 2D raster map

       rgbmaps=name[,name,...]
           Three (R,G,B) 3D raster maps to create RGB values [redmap,greenmap,bluemap]

       vectormaps=name[,name,...]
           Three (x,y,z) 3D raster maps to create vector values [xmap,ymap,zmap]

       zscale=float
           Scale factor for elevation
           Default: 1.0

       precision=integer
           Number of significant digits (floating point only)
           Options: 0-20
           Default: 12

DESCRIPTION

       The  module  r3.out.vtk  outputs  3D raster maps into VTK-ASCII format.  Maps are valid 3D
       raster maps in the current mapset search path. The output  parameter  is  the  name  of  a
       VTK-ASCII  file  which  will be written in the current working directory. If output is not
       specified then standard output (stdout)  is  used.  The  module  is  sensitive  to  region
       settings (set with g.region).

NOTES

       This  module  generates structured points with celldata (default) or pointdata. If top and
       bottom surfaces are requested an unstructured grid with celldata or a structured grid with
       pointdata  is  generated.   This  data  is put in a simple VTK-ASCII file. Neither XML nor
       binary output are supported. It is possible to choose more then one 3D raster  map  to  be
       written  in the VTK-ASCII file. Each celldata is named as the 3D raster map it represents.
       The user can visualize this file with the VTK Toolkit, ParaView and MayaVi which are based
       on  VTK. In case of 3D raster map with partially no data, the threshold filter in ParaView
       can be used to visualize the valid data. Just filter all data which is greater/lesser than
       the chosen null value in the VTK-ASCII file.

       The  top  and  bottom  region values are expected in meters.  If a Latitude-Longitude (LL)
       coordinates are used, the elevation value for each voxel will be converted into degrees.

       The input, rgbmaps and vectormaps parameters are optional, so only  the  geometry  can  be
       exported.

       If  the  user  defines  top  and  bottom  and  the  2D and 3D region values differ, the 2D
       resolution will be adjusted to the 3D resolution.  The  elevation  maps  are  expected  in
       meters.  If Lat/Long coordinates are used, the elevation will automatically converted into
       degree.  If the surface and bottom maps are in a different unit than meters, use the scale
       parameter to convert them into meters.

       The RGB voxel data can be created from 2D raster maps (Landsat TM images) with r.to.rast3.
       The values of the RGB maps must be within 0 and 255. If not, the values are  automatically
       set to 0 and warnings will be printed to stderr.

       The  vector  data  is  created  from  three  3D  raster maps. Each map represents a vector
       component.  So x, y and z components  are  required  in  this  order.  This  data  can  be
       visualized with Glyph3d or StreamTracer filters within Paraview.

       If the -c flag is used and the data should be visualised together with other data exported
       via *.out.vtk modules, be sure the -c flag was also set in these modules.  But  this  will
       only  work  with  data  from  the  SAME  location (the reference point for the coordinates
       transformation is based on the center point of the default region).

   Difference between point- and celldata
       r3.out.vtk can export 3D raster maps with different representations.

           ·   pointdata -- the cells/values are represented by the center of the  cell.  Instead
               of  cells,  points are created. Each point can hold different values, but the user
               can only visualize one value at a time.

           ·   celldata The cells are created with the same hight, width and depth as  in  GRASS.
               Each  cell can hold different values, but the user can only visualize one value at
               a time.

EXAMPLE

   Simple Spearfish example
       g.region -d
       g.region res=150 res3=150 t=80 b=0 tbres=10
       r.mapcalc "bottom = 1800. - elevation.10m"
       # synthetic data, could be geological structures:
       r3.mapcalc "map3d = row()+col()+depth()"
       #export of volume to VTK:
       r3.out.vtk -s input=map3d top=elevation.10m bottom=bottom output=/tmp/out.vtk
       # visualize in paraview or other VTK viewer:
       paraview --data=/tmp/out.vtk

   Spearfish example with RGB data
       #set the region
       g.region -d
       g.region n=4926970 s=4914857 w=591583 e=607793 res=50 res3=50 t=80 b=0 tbres=10
       #create a bottom surface
       r.mapcalc "bottom = 1800. - elevation.10m"
       # synthetic data, could be geological structures:
       r3.mapcalc "map3d = row()+col()+depth()"
       #get some satellite images with r.in.onearth
       r.in.onearth -l output=Sat tmband=Red
       r.in.onearth -l output=Sat tmband=IR1
       r.in.onearth -l output=Sat tmband=IR2
       #Convert the 2D maps to 3D raster maps with r.to.rast3
       r.to.rast3 input=SatLandsatTM_Red output=SatLandsatTM_Red
       r.to.rast3 input=SatLandsatTM_IR1 output=SatLandsatTM_IR1
       r.to.rast3 input=SatLandsatTM_IR2 output=SatLandsatTM_IR2
       #export of volume to VTK:
       r3.out.vtk -s rgbmaps=SatLandsatTM_IR1,SatLandsatTM_IR2,SatLandsatTM_Red
       input=map3d top=elevation.10m bottom=bottom output=/tmp/out.vtk
       # visualize in paraview or other VTK viewer:
       paraview --data=/tmp/out.vtk

   Spearfish example with vector data
       # set the region
       g.region -d
       g.region n=4926970 s=4914857 w=591583 e=607793 res=50 res3=50 t=80 b=0 tbres=10
       # create a bottom surface
       r.mapcalc "bottom = 1800. - elevation.10m"
       # synthetic data, could be geological structures:
       r3.mapcalc "map3d = row()+col()+depth()"
       # synthetic vector data, could be groundwater stream vectors
       r3.mapcalc "x_part = sin(row())"
       r3.mapcalc "y_part = cos(col())"
       r3.mapcalc "z_part = sin(depth())"
       # export the stuff data to VTK:
       r3.out.vtk -s vectormaps=x_part,y_part,z_part input=map3d top=elevation.10m
       bottom=bottom output=/tmp/out.vtk
       # visualize in paraview or other VTK viewer:
       paraview --data=/tmp/out.vtk
       # Now use the Glyph and Stream-Trace Filter to get nice vectors and streamlines

   Slovakia3d example
       #reduce resolution:
       g.region -dp3 res=1000 res3=1000
       r.mapcalc "bottom = 100"
       #export of volume to VTK:
       r3.out.vtk -s in=precip3d.500z50 top=dem500 bottom=bottom \
          output=/path/to/slovakia3d.vtk
       # visualize in paraview or other VTK viewer:
       paraview --data=/path/to/slovakia3d.vtk
       # set Display style to ’surface#
       # set Actor Control z to 10

SEE ALSO

        r.out.vtk, r3.out.ascii, g.region

AUTHOR

       Sören Gebbert

       Last changed: $Date: 2018-11-22 07:39:19 +0100 (Thu, 22 Nov 2018) $

SOURCE CODE

       Available at: r3.out.vtk source code (history)

       Main index | 3D raster index | Topics index | Keywords index  |  Graphical  index  |  Full
       index

       © 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual