## DESCRIPTION

Creates a display file from an existing grid3 file according to specified threshold levels. The display file is a display list of polygons that represent isosurfaces of the data volume. If specific levels are given, additional optional parameters are ignored. Min or max may be used alone or together to specify a sub-range of the data. The step parameter is given precedence over tnum.

### Flags:

-q
  Suppress progress report & min/max information
-f
  Use flat shading rather than gradient

### Parameters:

grid3
  Name of an existing 3dcell map
dspf
  Name of output display file
levels
  List of thresholds for isosurfaces
min
  Minimum isosurface level
max
  Maximum isosurface level
step
  Positive increment between isosurface levels
tnum
  Number of isosurface threshold levels
  Default: 7

## Example:

With grid3 data (phdata) in the range 3-7, we only want to see isosurface values for the range 4-6. Any of these commands will produce the same results:

    r3.mkdspf phdata dspf=iso min=4.0 max=6.0 tnum=5
    r3.mkdspf phdata dspf=iso levels=4.0,4.5,5.0,5.5,6.0
    r3.mkdspf phdata dspf=iso min=4.0 max=6.0 step=0.5

## NOTE

Currently the grid3 file must be in the user's mapset since the display files being created are specific to particular grid3 files and are contained in directories under them. We should create a mechanism where users may make display files from others' grid3 files without having to copy them to their mapset.

## AUTHOR

Bill Brown, bbrown@gis.uiuc.edu

Last changed: $Date: 2004/06/17 15:04:16 $