Selecting by illuminance / Daylight analysis

[Eamon]

Been lurking around here for 3 or four years under one form or another, but finally might have something of interest to a few people...

I posted this on cgtalk yesterday, but its probably more appropriate here.

I was wondering if it is possible to select objects, or sub-objects by the amount of illumination (vertex lighting?) contained in the mesh after calculating a radiosity solution?

Here's the scenario:

I want to fill an accurately modelled room with a 3d array of triangles, with their shadow casting turned off. Say, a 1cm wide triangle at each grid point of a 10cm three dimensional grid which fills the entire room. I would then run the radiosity solution, using an IES sky or other photometric lights in conjunction with the photometric illuminance exposure setting - as long as shadow casting (of the grid objects) is turned off, I now have an accurate three dimensional graph off the illuminance levels in the room. By being able to select and delete all of the triangles with an illuminance of less than say 50lux (required minimum for reading), I'd be able to show a point cloud, so to speak, of the areas within the room suitable for reading.

Phew! That took longer than I thought! I'd appreciate if anyone has any thoughts on this potentially interesting workflow for daylight analysis. The end intention is that I'd be able to generate a mesh from the resulting point cloud, to give a more tangible view of daylighting conditions for different windows/lightshelves etc.