irrEdit Lightmapper explained

Recently I wrote a lightmapper and included it into irrEdit, the Irrlicht Editor, but I didn't release it yet because it's still a toy. Several questions arised and I'm going to answer some of them here. But first, here's a shot of the light map generator in action:

How does it work?

Simple. It generates a new mesh, with a new texture coordinate set and meshbuffers, and draws lightmap pixels onto the new textures. That's it.

How fast is it?

Quite fast. Needs about half a second for a small room with 3 point lights and shadows enabled as shown above. But I didn't test it out with huge levels and hundreds of lights yet.

Why is it that fast?

I don't know. I just wrote it. Maybe because it's still simple.

What lighting model are you using?

Simple diffuse direct lighting. Global illumination to be implemented later maybe, would be possible without a lot of changes.

How much until it is finished and usable and released?

Depends on how much work I've still to do with Irrlicht. A month, two months maybe.