Re: [matplotlib-devel] Some update on GL backend

[Nicolas R. <Nic...@in...>]

Thanks. Apart from the speed, an OpenGL backend could be also useful for the ipython notebook using webgl (but I'm a total newbie at webgl).

Nicolas


On Aug 1, 2012, at 12:07 , Damon McDougall wrote:

> On Wed, Aug 01, 2012 at 11:24:06AM +0200, Nicolas Rougier wrote:
>> 
>> 
>> Hi all,
>> 
>> 
>> I'm continuing experimenting various solution for a possible GL backend for matplotlib and I made some progress (but no integration yet).
>> 
>> You can check results (and experimenting yourself at various places, sorry for that):
>> 
>> Text : http://code.google.com/p/freetype-gl/
>>       http://code.google.com/p/freetype-py/
>> 
>> Images interpolation & 3D : http://code.google.com/p/glumpy/
>> 
>> Lines/Shapes : http://code.google.com/p/gl-agg/
>> 
>> The last experiments (gl-agg) were about high-quality lines and shapes. It seems OpenGL may offer pretty decent quality (IMHO) as you can see on the various screenshots that compare agg and opengl. demo-lines.py and a demo-circles.py show zooming/panning speed (mouse drag / scroll).
>> 
>> There are still some more work to, mainly concave polygons and bezier filled shapes.
>> 
>> However, the whole integration into matplotlib may require a lot of work since OpenGL technics may radically differ from their matplotlib counterpart in some case. For example, a grid is rendered using a single shader that manages internally all the lines and ticks. Another example is image interpolation that is done entirely on the graphic card (see glumpy).
>> 
>> Also, Don't be fooled by the speed of the current demo-lines.py and demo-circles.py because they don't offer the versatility of matplotlib.
>> 
>> 
>> 
>> At this point, I may lack time to write the actual integration into matplotlib and I may not know enough the internal matplotlib machinery. Maybe this could be a future project for next year / Google summer of code ? What do you think ?
>> 
>> 
>> Nicolas
> 
> Nicholas,
> 
> There's a word for people like you: 'Hero'.
> 
> The output, in my opinion, looks very nice. Personally, I don't see
> myself using this for the two-dimensional stuff unless it's because I
> need to quickly look at something (just like you mention on the glumpy
> main page), but I think this is a winner for producing 3D plots. GL is a
> champion when it comes to 3D rendering, a la MayaVI, VTK or Paraview and
> the current mplot3d toolkit is using all of matplotlib's two dimensional
> capabilities. I would love to have something like this that mplot3d can
> hook into to produce publication-quality visualisations in
> three-dimensional space.
> 
> I have no experience with the backend side of matplotlib, I just wanted
> to say thank you for your effort :)
> 
> -- 
> Damon McDougall
> http://damon-is-a-geek.com
> B2.39
> Mathematics Institute
> University of Warwick
> Coventry
> West Midlands
> CV4 7AL
> United Kingdom