RE: How to populate a set of isosurfaces by giving a set of (x, y, z, value)

  • To: "Tom Rink" <rink@xxxxxxxxxxxxx>
  • Subject: RE: How to populate a set of isosurfaces by giving a set of (x, y, z, value)
  • From: "Chien-Ting Chen" <cchen@xxxxxxxxxx>
  • Date: Wed, 25 Sep 2002 15:18:34 -0700
Thanks for the help!!!

I encountered the other problem that when I display a set of volumes (
(x,y,z)->(concentration) ) and
map the "concentration" to Display.RGBA. To make a "foggy" effect in low
concentration values,
I set the RGBA table for each volume. When I displayed multiple sets (
multiple maps of RGBA ),
the transparency didn't work well:
    Transparent area in a set shelters other other volume set data. It looks
like a front invisible object cull out a back object,
but I exepct it should not cull out any object in the back if it is

Do you have any solution for it?

Thanks again,


-----Original Message-----
From: owner-visad-list@xxxxxxxxxxxxx
[mailto:owner-visad-list@xxxxxxxxxxxxx]On Behalf Of Tom Rink
Sent: Tuesday, September 24, 2002 9:59 AM
To: cchen@xxxxxxxxxx
Subject: Re: How to populate a set of isosurfaces by giving a set of

Hi Tim

An easy way would be to define a separate RealType for each
number of IsoSurfaces, each representing the same range
  (x,y,z) -> (RealType1, RealType2, RealTypeN)

Then map:
  RealType1 -> IsoContour
  RealType2 -> IsoContour
  RealTypeN -> IsoContour

This would waste memory,  but you could try  reusing the
domainSet in separate FlatFields using the
 FlatField.setSamples(float[][] range, boolean copy) with
copy == false.

 For a couple of isosurfaces, I wouldn't think this would be
to bad.

Tom Rink

Curtis Rueden wrote:

> Hi Tim,
> It sounds like VisAD does what you want, except that you want to
> set multiple iso-surface values simultaneously, instead of just
> one.  You may be able to extend VisAD's iso-contour logic to do
> this, or it may be that there is an easier way (although I don't
> know of one).
> Bill Hibbard may be able to comment further on this once he
> returns from vacation.
> -Curtis
> At 07:03 PM 9/20/2002, Chien-Ting Chen wrote:
> >Hi,
> >
> >I need to generate a set of isosurfaces by inputing a set of (x,y,z,
> >tuples.
> >
> >for example, I have a 100 (width) X 100 (height) X 50 (depth) = 500,000
> >y, z, value) tuples
> >The mapping from value to Display.IsoContour seems only work for
> >a surface texturing with the IsoContour,
> >but I need a set of IsoSurfaces to display by giving a set of Isovalues.
> >
> >How to do that?
> >
> >thanks for helping me.
> >
> >Tim Chen