When you have an object with backfacing polygons that are visible to the camera, they tend to be dimly lit at best, like this:

IDL helps but not enough:

I found that using the Alternate_Diffuse channel instead of the DIffuse_Color will solve the problem sometimes, but not always. I'm sure there's some principle involved here, and I hope someone can let me know what it is.

Have you tried ticking the normals forward box in the material root node?

DOH!!! Dammit! Is that it? One of the things that worked for me in my tests was using a Diffuse node but only if Normals_Forward was checked on it. I hadn't even noticed the root node had a Normals_Forward. So what is Normals_Forward anyway?

ElZagna posted at 3:19AM Sun, 11 March 2018 - #4325890

DOH!!! Dammit! Is that it? One of the things that worked for me in my tests was using a Diffuse node but only if Normals_Forward was checked on it. I hadn't even noticed the root node had a Normals_Forward. So what is Normals_Forward anyway?

Forces all the poly normals to point towards the camera, so they look properly lit.

Boni posted at 5:19AM Sun, 11 March 2018 - #4325892

We are a good bunch here, ain't we, Boni? I mean, we get stuff done. :)

We do Sam ... we are here for each other. And that is what the forums are about!!