I have a model of a head. I didn't model the inside of a mouth or anything so it's just a hole in the mesh. When I render it, I can see the texture that I applied to the outside of the mesh on the inside. All I want is for the inside of the mesh to be solid, non-reflective black. How can I do this without screwing up the outside texture?
-
1what render engine are you using? – Apr 14 '16 at 19:36
-
I'm using Cycles – Dana Apr 14 '16 at 20:10
-
@Daniel You should include that in the title or question in future questions. :) – Luka ash Apr 15 '16 at 00:35
2 Answers
Use the "backfacing" output from the geometry node (input section).
The output will make the side of the face in which the normal is pointing equal to 0, and the other side (back) equal to 1. This can be used in a mix node.
Note: make sure that all your normals are facing the right direction (crtl+n)
Try this nodes setup.
- 2,286
- 12
- 17
-
This is a duplicate. See http://blender.stackexchange.com/questions/2082/how-can-i-make-a-material-only-apply-to-a-side-of-a-plane – Shady Puck Apr 14 '16 at 20:19
-
Yes, thank you, but this should be posted on the question, not the answer. Also, the questions were a little different. – Uncle Snail Apr 15 '16 at 18:44
Slight work around, but creating a face on the mouth, by selecting the edges of the mouth and press F to create faces then creating a new material of the type holdout should make it a complete black. EDIT: Some more info:
Pretend this open side of this sphere is your mouth. 
Select all the edges of the mouth and press F(Or select Mesh > Faces > Make Edge/Face) to create a new face. 
There, now go to your materials panel, create a new material and set it's shader type to "Holdout" 
There, we have a mouth, unlike setting this to black, this not reflect any light and will stay complete black no matter what.
- 669
- 5
- 17
-
The problem with doing it this way is that I made a dumb mistake and applied all of my subdivisions, so Now I have a crazy complex model and every time I try to just put a face in the mouth, it messes with my shape keys. – Dana Apr 16 '16 at 14:41
-
@Daniel Not so sure what you mean, any chance i can take a look at the model for you? – Luka ash Apr 16 '16 at 19:08

