Re: [Avogadro-devel] Rendering Order

[Donald E. C. <don...@ui...>]

You are exactly right about counting objects.

Consider though that if each object is a primitive and more than one
engine is rendering all primitives you easily double the number of
display lists.  We could also consider "grouping" where all opaque
objects for an engine are all grouped into one display list.

I am curious to try out this z-depth based rendering with a two pass.
Unless there is any major objections i'm going to put in a few hours
with it today and see how it turns out.

(Tue, Apr 10, 2007 at 12:16:50PM -0400) Geoffrey Hutchison <ge...@ge...>:
> 
> On Apr 10, 2007, at 11:44 AM, Donald Ephraim Curtis wrote:
> 
> >The max num of display lists plays a role because what about when we
> >have so many things to display that we overflow?  Is that even  
> >possible?
> >Will we ever be asking to render 4.2 billion objects?
> 
> One caveat. On some OpenGL implementations, that maximum is across  
> all active OpenGL applications at once. I don't know if Qt hides that  
> from us and really creates a separate context for
> 
> In the end, it depends on how you count an object. Since a display  
> list represents some number of OpenGL calls, probably not. Most  
> people seemed happy with Open Babel 2.0 which only had 2^16 atoms.  
> Now a few more have proteins with ~300k atoms. Even if you expand  
> that a bit to ~2 million atoms, we're still *far* from running out of  
> display lists.
> 
> Cheers,
> -Geoff