Using emission shaders to illuminate the interior of primitives

The Brig

I've got a scene where a figure is inside a cylinder and I'm trying to get the walls of the cylinder to provide illumination to the figure. Here's what I've done to the cylinder in the Surfaces pane so far:

Applied the emissive shader; set Material ID, base color, and emission color to white (255, 255, 255); then set Two-Sided Light to "on" and set the luminance to 100,000 lumens.

I haven't made any other changes and the scene still renders black. What steps could I be omitting?  Or does the emissive shader only apply to the exterior of primitives like this one?

kaotkbliss

It might be the units your lumins are using, some units take a crazy high number (even hgher than 100k) try changing and see if that helps.

If not, I think there is an option in the geometry editor to flip normals, than may work to get the other side of the poly's facing inward.

maclean

Don't ramp up the light value. Instead try setting Tone Mapping> Exposure Value to something like 4.0. That may be too bright, but if it is, just go higher with the value. Or lower, if it's still dark.

If you get nothing at all, it means you need to flip the polys to face inwards.

The Brig

kaotkbliss said:

If not, I think there is an option in the geometry editor to flip normals, than may work to get the other side of the poly's facing inward.

That was it. Thank you and a tip of the hat to you!

kaotkbliss

maclean said:

Don't ramp up the light value. Instead try setting Tone Mapping> Exposure Value to something like 4.0. That may be too bright, but if it is, just go higher with the value. Or lower, if it's still dark.

If you get nothing at all, it means you need to flip the polys to face inwards.

Yeah, I was more hinting at changing the unit type, but I had a render going so I couldn't look to see which one I wanted to suggest