Re: Creating 3D Cone

• To: Kevin Manross <kevin.manross@xxxxxxxx>
• Subject: Re: Creating 3D Cone
• From: Bill Hibbard <billh@xxxxxxxxxxxxx>
• Date: Wed, 10 Dec 2003 17:06:02 -0600 (CST)

Hi Kevin,

> While I might still try the warped 3D cone, I am currently focusing on
> creating an ellipse at descrete points along the radar radial.  I have
> sucessfully created the ellipse and will soon map it to lat/lon/elev
> coords and resample the terrain data.
>
> My new question with this technique is can VisAd tell me the percentage
> of data that fills the ellipse?
>
> More specifically, if I use a Gridded2DSet (ellipse) to resample terrain
> data (lat,lon)->alt, is there a (simple) way to calculate the number of
> alt values that have been sampled with respect to the size of the ellipse?
>
>
> Eg.
>
>              ********
>             *        *
>            *    |     *
>            *    ||    *
>             *  |||   *
>              ********
>
> 20% of the ellipse is filled by alt values.

The only thing that VisAD can offer is the computeArea() method
of DelaunayCustom.java, with a Gridded2DSet argument (with
manifold dimension = 1 this is a polygon boundary). So if you
can describe your ellipse with a 2-D boundary line, and the
part filled by alt values by another 2-D boundary line, just
take their ratio. Otherwise, you'll have to code your own
algorithm.

Good luck,
Bill

• References:
  • Re: Creating 3D Cone
    • From: Kevin Manross