[Bf-funboard] Fwd: Critical improvements and features

[Brecht Van Lommel]

On Fri, Sep 20, 2013 at 12:57 AM, David Jeske <davidj at gmail.com> wrote:
> It would be nice to hear comments from someone in-the-know on this.
>
> Is this strictly a GL drawing performance issue? For example, I know
> drawing many independent sets of gl-lines from a derived mesh which is
> merely triangulated is pretty slow. Likewise, using old-school immediate
> glVertex3f style calls is pretty darn slow, and I think blender does both.
> (though I could be wrong?)
>
> Even if Blender is going to support really old GL for compatibility
> reasons, it might be time to start using GLSL to render the viewport
> whenever it is available. Then we could write much faster GLSL shader code
> to handle all viewport drawing modes (solid, textured, wire, xray, etc)...
> using techniques like single-pass wireframes.
>
> This might be some of the thinking behind Ton's plan to incorporate the
> Blender-game-engine as an interactive viewport. However, it might be a
> smaller change to make a fully capable GLSL-120 rendering mode for the
> standard viewport features.

There's a few different issues to solve here to get optimal
performance: using the GL core profile on cards that support it,
getting rid of immediate mode entirely, smarter use of VBO's with
fewer CPU work and state changes, using more optimized GLSL shaders,
.. and just generally profiling and analyzing performance to find and
optimize bottlenecks.

No reason this can't be done, it's just a ton of work and quite
independent of any game engine work. That's the case for most features
on the list by the way, editing multiple selected objects at once,
more advanced outliner, multi-object editing, .. simply no one has
dedicated the time to implement them yet.

Brecht.