Re: [PyOpenGL-Users] VBO help and performance

[Wakefield, R. <rjw...@en...>]

Thanks Ian, that really helps.  Have you ever had any issues with very small float values in pyOpenGL?  I can get a good savings by bunching all backgrounds/foregrounds in 1 render call, but to do that I'll need to put a visually indistinguishable z-distance between the two middle layers (ex. 0.00002), so the player sprite can be placed between them without visual distortions.  I'll try the IBO combined with that and see how it goes.
________________________________________
From: Ian Mallett [geo...@gm...]
Sent: Thursday, May 06, 2010 9:30 PM
To: Wakefield, Robert
Cc: Greg Ewing; pyo...@li...
Subject: Re: [PyOpenGL-Users] VBO help and performance

On Thu, May 6, 2010 at 6:17 PM, Wakefield, Robert <rjw...@en...<mailto:rjw...@en...>> wrote:
The issue I see is that I send much less net data (a few pointers and sizes instead of a full index array), but I'd also need to make ~20 or so calls per frame.
What you'll really want to avoid is binding and unbinding VBOs as much as possible.  For objects with multiple materials, my object class uses separate VBOs.  For objects with around 10 materials, that's quite a few operations.  I'm going to have to convert the VBOs to an interleaved VBO to raise performance.  Long story short, I reiterate: try to minimize VBO binding.
Ian