Vicky 6 SSS oddness

Sertorial

I seem to be getting some sort of weird halo around Vicky 6's mouth.

These renders are the Vianne character and I am using a simple 3 point spotlight set up.

One is the 75% SSS MAT and the other is the 25% SSS MAT. Notice the weird effect around her mouth in the latter. What am I doing wrong?

Trish

Have you checked the spread angle on your light....???Also what settings do you have on the lights??

Khory

It is due to sss on things like her teeth and inner mouth. Check and see if there is a setting to turn that off on those surfaces. If not go to the surface tab and select anything that would be inside the mouth and turn it off there.

Richard Haseltine

Or give them a different SSS group number so that they don't scatter into the face. It also helps to have shadows on all your lights, though that may not be desirable for other reasons.

mark128

Do you have shadows on all the lights, especially the back light? If you don't have shadows on the rear light you can sometimes get effects like this because the rear light will go right through the head.

Sertorial

thanks everyone! It never occured to me that I'd have to put shadows on a back light! But that fixed it.

How come I don't have to do that with other figures? Is it because V6 has this strange new shader I've just noticed? It called AoD sub_surface (actually the materials tab for V6 is pretty terrifying!)

alexhcowley

Khory said:

It is due to sss on things like her teeth and inner mouth. Check and see if there is a setting to turn that off on those surfaces.

I've had this problem. In my experience, the simplest fix is the one suggested by Khory. If you actually need SSS inside the mouth, this solution will not be appropriate, of course.

Richard Haseltine

Sertorial said:

thanks everyone! It never occured to me that I'd have to put shadows on a back light! But that fixed it.

How come I don't have to do that with other figures? Is it because V6 has this strange new shader I've just noticed? It called AoD sub_surface (actually the materials tab for V6 is pretty terrifying!)

It's an issue with sub-surface scattering - light being bounced around inside the mesh and coming out again. It can happen with other SSS shaders (Human Surface Shader and uberSurface, for example) too.

Herald of Fire

Sertorial said:

thanks everyone! It never occured to me that I'd have to put shadows on a back light! But that fixed it.

How come I don't have to do that with other figures? Is it because V6 has this strange new shader I've just noticed? It called AoD sub_surface (actually the materials tab for V6 is pretty terrifying!)

Light which doesn't have shadows passes straight through the material, causing subsurface calculations when it strikes the surface from the opposite side. This can cause the noted 'lightbulb face' as well as plenty of other oddities and artefacts. The AoA subsurface shader (which is V6's default) creates some very pronounced subsurface effects, which makes it stand out even more than some other shaders do, however you'd get the same problem using UberSurface and its subsurface settings as well.