Make backside of faces black instead of invisible

Development Rendering
1

Hi
Im wondering if i can make the backside of faces appear black so that it blends in with the backround instead of it being invisible.
I could cover it with gemoetry, but then it would be colored by light and not blend in prefectly, i want it to be system black. Im attaching a picture that
shows what i mean.

2

try make a material with 0 albedo color, 1 roughness and 0 specular

3

Ty :slight_smile: Ill try that

4

In case you cover it with geometry use simple unlit material without any additional nodes.

But if you want to do it without geometry, so I think it is possible using surface normals.
In your material check “two sided” option.
Then get “world normal” and make it dot product with camera vector.
This returns black and white values depending on view angle.
Here you can mask that values with “if”.
If dot >= 0, return 1;
If dot < 0, return 0;

Finally using Lerp node you will interpolate
base color and 0
roughness and 1
specular and 0
And so on for other paramereters.

But I think in you case its better to use black unlit material on additional geometry )))

5

You can just use the TwoSidedSign node, instead of the dot product.

1 Like
6

Thx guys. It worked: )