Re: The random colour changing bug

Hi Andrew,

Thanks for the test program. Unfortunately, it does
not cause any color change on my home machine (a
laptop running Windows NT, JDK 1.2 and some ancient
version of Java3D). I looked at the mailing list
thread that Ugo recommended (thanks Ugo) and it seems
at the time we thought it might be related to ambient
light being turned off, and were very puzzled how this
could happen. Clearly your test program is not accessing
its Java3D scene graph, so that hypothesis is out.

Next time I'm in the office I'll try your test program
on my office machine (running more recent versions of
Java and Java3D). Do any other Wisconsin folks see the
color change running Andrew's test program?

Its hard to imagine how VisAD is doing this, but of
course it isn't impossible. It may be useful to inquire
on the Java3D list whether this is a known Java3D bug.


On Mon, 21 Nov 2005, Andrew Donaldson wrote:

> Hi,
>    For some time many of us here at the Bureau of Meteorology have
> been aware of our VisAD apps changing colour for an unknown reason.
> I vaguely recall showing this to Bill when he last visited, but I
> am uncertain of this.
>    It has recently become a problem, with some of our operational people
> wanting to choose specific colours, only to have them changed by
> our applications.
>   On every computer we have tried it on (including Linux nvidia, windows
> opengl and windows directx) the fault occurs.
>   Attached is a simple program which displays a yellow box.  If you click
> with your middle mouse button, the yellow box becomes darker.  This
> thought to be the same problem that our applications have.  The sample
> program does not have any code to respond to a mouse button or change
> colours.
>   Any help would be very greatly appreciated.
>   I think we first need to work out if the problem is with java3d or
> VisAD.  I don't have a good understanding of all the things that happen
> when the middle mouse button is pressed, hopefully someone else can
> add to this!
> thanks,
> Andrew.