DMX and 3D Compositing Questions

[Tomas Carnecky]

Kevin E Martin wrote:
> On Fri, Jul 25, 2008 at 02:06:21PM +0200, Christian Pirchheim wrote:
>> Now, here comes my question: What does it take to make DMX compatible
>> with 3D compositing window managers? Background of my question is, that
>> we would like to create large seamless displays combining multiple
>> overlapping projectors. Within the composite window manager, the desktop
>> geometry and window textures are available, allowing to compensate for
>> geometric and photometric distortions.
 >
> The other issue here is that if you're looking at compensating for
> various distortions and have a non-planar display surface, then don't
> forget about the input side.  You'll need a way to translate input
> events to the appropriate window coordinates, and if those windows are
> out of the standard display plane that the X server assumes, you'll need
> to compensate.  Various people have discussed the options here, but I
> have not seen much activity recently.

I'm working on a color management plugin for compiz (basically applying 
ICC profiles using shaders). When I presented my idea at the Libre 
Graphics Meeting (LGM) 2008, Øyvind Kolås (aka pippin, GIMP developer) 
approached me and described exactly this situation (two or more 
overlapping projectors) and what the problems are (geometric/photometric 
corrections) and said I should keep this in mind when implementing the 
plugin, so that when this situation appears, I wouldn't have much 
trouble adding the needed features to the plugin. I didn't think about 
it much further, but hey, here we are :)

I don't know how such corrections could be added to my plugin, but the 
plugin itself is really small and easy to understand (if you know 
OpenGL). If you really want, I could think something up and then we can 
discuss it. So if you are looking into extending the color plugin or 
writing a new one, feel free to ask me.

About input transformation, at least in the use-cases that were 
presented to me at LGM, no input transformation is needed. But I don't 
know what your specific setup is so I can't really comment on that.

tom