Re: Problem with off-screen render

On Wed, 1 Sep 2004, Bill Hibbard wrote:

> The bottom line of all this is that Java3D does not work
> in a "headless" environment. But that "headless has" a very
> specific definition in Java. It is quite conceivable that
> a system without a physical display does not have to be
> headless - it may still support OpenGL in purely offscreen
> mode (I don't know for sure that this is possible, but
> wouldn't be surprised).

I checked with the Java3D mailing list and learned from
Kevin Rushforth, Sun's Java3D leader, that while this is
theoretically possible he does not know of any current
implementations. Here's what he said:

  The only way Java 3D could run on a system without a
  physical display is if that system ran a virtual X
  server (e.g., something like VNC) that also supported
  the GLX extension and OpenGL library. I am not aware
  of any such implementations.

  In the future, we are exploring the possibility of a
  headless OpenGL for Pbuffer-only rendering, but that
  will require driver support from the graphics card
  manufacturers.

But also note that VisAD can still do offscreen Java3D
rendering on servers with physical displays, and can do
Java2D rendering on headless systems.

Cheers,
Bill