Re: Display.IsoContour and transparency

• To: Olav Rybatzki <520024853634-0001@xxxxxxxxxxx>
• Subject: Re: Display.IsoContour and transparency
• From: Bill Hibbard <billh@xxxxxxxxxxxxx>
• Date: Wed, 28 Jan 2004 04:58:25 -0600 (CST)

Hi Olav,

It is very hard to get Java3D to render transparency correctly
because transparent geometry needs to be sorted in Z order to
render correctly. You have some control over rendering order
between different Data objects by the order of their calls to
Display.addReference(). You might experiment with that order.

By the way, I have just released to the VisAD ftp server Tom
Rink's fixes to the problems you reported earlier under the
Subject "Questions about Streamlines, FlowControl, and
FlatField.resample()". Thanks for finding these problems.

Cheers,
Bill

On Wed, 28 Jan 2004, Olav Rybatzki wrote:

> Hallo,
>
> i have a problem with isosurfaces and transparency. If i pass 2 Sets,
> volume data  mapped to Display.IsoContour and a surface (may be of an
> airplane) mapped to RGB or RGBA, to a display it is sometimes not
> possible to see the surface. My idea now is to give the volume data a
> ConstantMap with Display.Alpha.
>
> display3D.addReference(iso_ref,
>        new ConstantMap[]{new ConstantMap(0.2, Display.Red),
>        new ConstantMap(0.6, Display.Green),
>        new ConstantMap(0.6, Display.Blue),
>        new ConstantMap(0.9, Display.Alpha)});
>
> display3D.addReference ( surface_ref);
>
> The problem is, that now i can see the box edges through the isosurface
> but the surface is always hidden. Is it impossible or have it to be done
> in a different way?
>
>
> Olav
>

• References:
  • Display.IsoContour and transparency
    • From: Olav Rybatzki