filled triangles

[Ricardo Mantilla]

Hi Bill,

I wanted to close this thread letting you know that I found that the 
strategy that you suggested of creating the FlatField was correct from 
the beginning. 

For some reason the line of code:

float theColor=3.0f*(float)Math.random();
java.util.Arrays.fill(colors[0],j*4,(j+1)*4-1,2.0f);

behaves differently from:

float theColor=3.0f*(float)Math.random();
for (int i = j*4; i < (j+1)*4; i++) colors[0][i]=theColor;

in a loop of j.  This was causing the colors array to end up with some 0's.

This is probably a Java1.5 on Mac OS X issue, completely unrelated to VisAD.

Cheers,
    Ricardo

Bill Hibbard wrote:
> Hi Ricardo,
>
> To get solid color triangles, all vertices of a triangle must have the
> same color. To achieve this, it may be necessary that each
> Irregular2Dset in the UnionSet consist of a single triangle (so that
> no triangles share any vertices).
>
> Good luck,
> Bill
>
>     ----- Original Message -----
>     From: "Ricardo Mantilla"
>     To: "Bill Hibbard"
>     Subject: Re: filled triangles
>     Date: Thu, 08 Mar 2007 21:54:41 -0700
>
>
>     Hi Bill,
>
>     Thanks for your suggestion, however I am getting a some color
>     gradients on my graph (attached) rather than flat colors inside the
>     triangles. It may be due to how I am setting up the FlatField. In
>     the code that follows "regions" is an Irregular2DSet[] array, and
>     "colors" is a float[] array with as many positions as points in all
>     the Irregular2DSet.
>
>     CODE FOLLOWS +++++++++++++++++++
>
>     RealType xEasting =RealType.getRealType("xEasting"),
>     yNorthing=RealType.getRealType("yNorthing"),
>     tileColor=RealType.getRealType("tileColor");
>
>     RealTupleType domainXLYL=new RealTupleType(new RealType[]
>     {xEasting,yNorthing});
>
>     FunctionType func_xEasting_yNorthing_to_Color=new
>     FunctionType(domainXLYL,tileColor);
>
>     UnionSet allRegions=new UnionSet(domainXLYL,regions);
>
>     FlatField theColors=new
>     FlatField(func_xEasting_yNorthing_to_Color,allRegions);
>     theColors.setSamples(colors);
>
>     DataReference region_ref = new DataReferenceImpl("region");
>     region_ref.setData(theColors);
>
>     display_TIN.addReference(region_ref);
>
>     CODE ENDS +++++++++++++++++++
>
>     What am I doing wrong?
>
>     Thanks,
>     Ricardo
>
>
>
>     Bill Hibbard wrote:
>     > Hi Ricardo,
>     >
>     > I am using VisAD to display a bunch of filled triangles (as shown
>     > in attachment). Since each triangle is supposed to be a different
>     > color my approach was to create an irregular2DSet for each one
>     > (using Delaunay.fill()) and then create a reference for each one
>     > with an associated constant map (describing Red, Green, Blue).
>     >
>     > However, this is awfully slow when I have hundreds of triangles. I
>     > was looking for something like creating an unionSet with the
>     > irregular2DSets with each irregular2DSet having a property
>     > associated to the color but I couldn't find a way to to it.
>     >
>     >
>     > Construct a FlatField with MathType ((x, y) -> (r, g, b)) and
>     use the
>     > UnionSet as the domain Set of the FlatField. Then you have
>     ScalarMaps
>     > of the Field range values to Red, Green and Blue, and fill the
>     triangle
>     > vertex colors into those range values.
>     >
>     > Good luck,
>     > Bill
>     >
>     >
>     > --
>     >
>
>     -- -------------------------------------------------------------
>     Ricardo Mantilla
>     Posdoctoral Research Associate
>
>     Department of Earth and Environmental Science
>     New Mexico Institute of Mining and Technology
>     801 Leroy Pl. MSEC 254
>     Socorro, NM 87801
>
>     Phone: (505) 835-5068
>     Office: MSEC 254
>     http://cires.colorado.edu/~ricardo/
>     -------------------------------------------------------------
>     << triangles2.png >>
>
>
> -- 
>
> <http://a8-asy.a8ww.net/a8-ads/adftrclick?redirectid=en-mail_a_01>
>

-- 
-------------------------------------------------------------
Ricardo Mantilla
Posdoctoral Research Associate

Department of Earth and Environmental Science
New Mexico Institute of Mining and Technology
801 Leroy Pl. MSEC 254
Socorro, NM 87801

Phone: (505) 835-5068
Office: MSEC 254
http://cires.colorado.edu/~ricardo/
-------------------------------------------------------------

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