You're running on a Mac, right?

In the past I've noticed depth ordering problems with the Mac version  
of Java3D and alpha.  But I thought Apple's since updated to sit  
Java3D on top of JOGL like everyone else so it should have gone away.

Java3D has a bunch of built-in options for specifying the ordering of  
transparent objects.  But the defaults are almost 100% what you want.   
So this has to be a bug.

So first test:  Try this out on (1) Windows and (2) XWindows

Test #2: modify appearanceForColor (which is what I'm assuming you're  
using) to use ALPHA_SCREEN_DOOR (or whatever it is called) instead of  
BLENDED.

 From there it's time to start hunting down the Java3D forums.  I  
agree, this is ugly.

Sean

On Sep 16, 2009, at 8:47 AM, Joerg Hoehne wrote:

> Hi,
> can anybody confirm this weird behaviour shown in the attached  
> files? I'm displaying a scene where
> the spheres have an alpha value of .9f (almost opaque). With this  
> alpha value the depth ordering is
> not working as shown in the image sequence (all image file names  
> below 10).
> The same scene with an alpha of 1.0f does not show the behaviour,  
> the depth ordering is fine (see
> the attached image sequence, all image file names from 10 and above).
>
> In the image sequence I'm moving the camera so the red sphere on the  
> bottom should be displayed
> above the purple sphere.
>
> Currently I don't have any short code sequence for demonstration  
> because I have first to extract it
> from the project.
>
> Regards,
> Jörg