SGI OpenInventor slow on GeForce3

[Klaus]

SGIs OpenInventor implementation is awfully slow on a GeForce3 graphics adapter.

I use SoQt and the problem occurs on
Win9x and Linux(drivers 12.51).

Does anyone have this problem too ?
Any ideas what the reason is ?

[This message has been edited by Klaus (edited 07-19-2001).]

[cyclone]

It's something that I have noticed on a *LOT* of C++ class/API/engines that encapsulate Opengl's commands.

I think that generaly, the biggest slowdown on the majority of their C++ class/API/engines is in the "pre-culling" process (cf. for don't draw the majority of polygons that aren't on the view fustrum)
=> they want always make this "big culling" on software when hardware with T&L can make this very more speedly with the more simple and hardware accelerated fustrum culling ...

@+
Cyclone

[Klaus]

Thanks cyclone for the answer,

i found the problem. I had to set the draw buffer to GL_BACK explicitely in SoQt's class Inventor/Qt/viewers/SoQtViewer.cpp in the actualRedraw method at the end of the method just before the actualRedraw call.

Don't know why this is necessary only on GeForce3.