Sculpt: Emit Light from Glow revision

Currently only a single point of light emission comes from a given sculpt, at the centre of mass. But the expected result would be light would come from all of the surface--to match the visual-only glow effect on the surface.

The problem here is, when you just go by the settings names and descriptions, you're almost certainly going to guess that you could draw out a long snaking sculpt, have it emit light, and you'll get a long snaking trail of light--which is not the case. So then this confuses the creator and they are required to test and experiment to figure out why it's not looking as cool as what they had in their head.

I am aware that doing so could be expensive to render... though it could even scale to the hardware, or perhaps in realtime based on the what else is going on in the render.

Also, paint has this working on every fleck of the painting, so maybe it wouldn't be that bad. And if we "convert to paint" and then had that emit light instead, it would emit light as expected. So simply cutting out the workaround and letting sculpts emit light across the surface would be great. Even if it was algorithmically-determined points across the surface, the same way flecks are positioned.