Re: [Matplotlib-users] 3d performance question

[Jason G. <jas...@cr...>]

On 12/18/12 6:53 AM, Sturla Molden wrote:
> Interactive 2D plots can be sluggish too, if you have enough objects in
> them. It is not the backend that is sluggish. Replacing the backend does
> not speed up the frontend.
>
> OpenGL is only 'fast' if you have a frontend that exploits it (e.g. uses
> vertex buffers and vertex shaders). If you just use OpenGL for
> bitblitting an image or drawing vertices individually (glVertex*), it is
> not going to help at all.
>
> My impression is that whenever Matplotlib is 'too slow', I have to go
> down to the iron and use OpenGL directly. It tends to happen when there
> are too many objects to draw, and the drawing has to happen in 'real-time'.
>
> Observe that if we let OpenGL render to a frame buffer, we can copy its
> content into a Matplotlib canvas. Unless we are doing some really heavy
> real-time graphics, displaying the image is not going to be the speed
> limiting factor. Even though using OpenGL to swap framebuffers will be
> 'faster', you will not be able to tell the difference in an interactive
> Matplotlib plotting.

I'm curious: how come Chaco is so much faster for real-time plots?  What 
are the main technical differences to enable it to plot things much more 
quickly?

Thanks,

Jason