OK, thanks Emmanuel.

In fact is not a great problem, usually I don't bother about Direct3D or OpenGL, as I don't see too many difference for the rather simple 3D visualization of the virtual visit mode. I just left it using Direct3D because that way the 3D output can be processed by Tridef 3D Ignition to generate a stereoscopic realtime image which can be viewed as a 3D image in a 3D monitor.

Nevertheless that's not something I do frequently, it's rather a curiosity, so if I need to do it again I'll do it the way you said.

Regards.