Request: Blenderscript for postpro

Hi,

been thinking a while about the compositing issue and came up with an idea, but this would involve some blender scripting:

For me most important for postproducing is the z-buffer, vector pass, the object index, as well as the alpha of the renderlayers.

Usually if you take a scene and make all materials shadeless and the background plain black, switch of raytracing, and AO, rendertime goes down to a couple of seconds, compared to a full render that could need 8 hours or more per frame.

But this shadeless scene will (in theory) deliver the same z-buffer, vector and object index values. Alpha usually is in the .PNGs from renderfarm.

So the script I imagine, takes a scene, automatically switches of the raytracing and stuff, switches all materials in scene to shadeless, 

sets up  output nodes for every renderlayer, each save the z-buffer / object index to a 0001_renderlayer1_z-buffer.exr / 0001_renderlayer1_object-index.exr, 0002...

Having this would give everybody the opportunity to just render the passes on their home machine within a small amount of time, and give the possibility of postproccessing after the farm.

p.s.: I know this would be only a temporary solution, but until compositing issue is fixed otherwise, such a script would come in handy. (If it doesnt need too much time to code that)