View Full Version : gluNurbsSurface ... runs slow and slower ... and stops ...

Andrew Jameson
06-25-2003, 05:50 AM
Apologies for cross posting - I thought that this would be a beginners question - but maybe not !

I decided to add a little more realism to a book ... turning pages ... at the moment a page is simply a hinged plane and it looks like it's made of steel ! So I tried to use a bezier surface ... and failed ...
I'm using a bezier surface with 12 control points ... based around a simple example by Jan Horn. Now when the program runs, there is a noticeable performance hit that continues to degrade until it all stops ...

What am I doing wrong ? Are bezier surfaces supported in hardware ? I noticed that there's not much on Nurbs and the example on NeHe's site actually uses triangle strips.

(I'm using a GeForce2 with the latest drivers.)


06-25-2003, 06:33 AM
No, they're internally tesselated into triangles and sent in immediate mode or with vertex arrays.

Have you checked your memory usage? Maybe you've got a memory leak somewhere, which quickly causes disk swapping ? Just an idea.

Other than that, i can't see why using Bezier surfaces would slow down anything.


Andrew Jameson
06-25-2003, 07:42 AM
Thanks ... My fault ... I didn't appreciate what the default GLU_SAMPLING_METHOD actually meant ! Now just need to figure out how to apply a texture !


06-25-2003, 07:53 AM
Originally posted by Andrew Jameson:
Are bezier surfaces supported in hardware ?Just for the record:
Everything with the glu prefix is layered on top of OpenGL and thus cannot be moved to hardware.
(I haven't seen a glu ship with graphics card drivers, and I doubt I ever will).

06-27-2003, 12:00 PM
I replied to this thread in the other forum.

Basically: memory leak.