Re: Delaunay Triangulation

• To: Desiree Hilbring <hilbring@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
• Subject: Re: Delaunay Triangulation
• From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>
• Date: Mon, 16 Oct 2000 13:11:46 -0500

Hi Desiree,

> I did manage to include the with VisAD created Delaunay Shape3D Object in
> my application.

Great.

>   /**
>      * Triangulation of given set of points with delaunay. This method
>      * throws an event, when 3D-Objects are ready. See displayChanged.
>      */
>     public void makeSurface() {
>         //System.out.println("Hallo Delaunay!");
>         RealType x = RealType.getRealType("x");
>         RealType y = RealType.getRealType("y");
>         RealType height = RealType.getRealType("height");
>         try {
>             RealTupleType xy = new RealTupleType(x, y);
>             FunctionType terrain_type = new FunctionType(xy, height);
>             Irregular2DSet set = new Irregular2DSet(xy,new float[][]
> {eastValues,northValues});
>             FlatField terrain = new FlatField(terrain_type, set);
>             terrain.setSamples(new float[][] {heightValues});
> 
>             display = new DisplayImplJ3D("display1");
>             ScalarMap hoxmap = new ScalarMap(x, Display.XAxis);
>             ScalarMap reymap = new ScalarMap(y, Display.YAxis);
>             ScalarMap heightmap = new ScalarMap(height, Display.ZAxis);
> 
>             display.addMap(hoxmap);
>             display.addMap(reymap);
>             display.addMap(heightmap);
> 
>             hoxmap.setRange(-1.0, 1.0);
>             reymap.setRange(-1.0, 1.0);
>             heightmap.setRange(-1.0, 1.0);
> 
>             DataReferenceImpl data_ref = new
> DataReferenceImpl("data_ref");
>             data_ref.setData( terrain );
>             renderer = new DefaultRendererJ3D();
>             display.addReferences(renderer,data_ref);
>             display.addDisplayListener(listener);
>         }
>         catch (VisADException ve) {
>             System.out.println("VisAd TupleType Exception");
>         }
>         catch (RemoteException re) {
>             System.out.println("RemoteExcpetion");
>         }
>         //System.out.println("Delaunay ende!");
>     }
> 
> Is it possible with visad to get a shap3d of a part of this triangulation?
> Say, I do have coordinates of a point and want to clip the parts of the
> object, which are more far away, than 10m, or something similar?

Yes, if you want to clip in x, y and/or height.  Just add
ScalarMaps from any of them to Display.SelectRange, then
do something like:

  RangeControl control = (RangeControl) range_map.getControl();
  control.setRange(low, hi); // set low and hi clip values

Note this is different from ScalarMap.setRange().  It should
give you the part of the irregular syrface within the clip range(s).

Cheers,
Bill
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html

• References:
  • Re: Delaunay Triangulation
    • From: Desiree Hilbring