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