Bump effect on an unlit material

Development Rendering
1

Is there a way to have a bump effect in a unlit material. I know that normally is is done with a normal texture, but with a unlit material there is no normal(and that make sense). BNut is there a way to have this bump effect always active (and that does not necessary reflect the lifght in real time but is still present as if it always had some light on it) even without light.

I dont know if I sound confusing, anyway thanks in advance for the help

2

Can you displace an unlit material? If so you could try doing that and using some Fresnel values on your Emmisive channel. Other than that I think you would have to draw in details onto your diffuse map but they would not be affected by light direction. Maybe Parralax Occlusion Mapping might help?

3

you would at least need a ‘fake’ light direction, which is the same principle used by the toon/celshaded materials people have made for UE4
with that light direction you can then reconstruct the logic behind normal mapping (and even use a normalmap for it) to achieve the same effect, which doesn’t seem like a very complicated task if you know your way around materials and material math

4

https://docs.unrealengine.com/udk/Three/FakeMeshLighting.html

5

Generally speaking, the “bump effect” itself perturbs the lighting normal and modifies the contribution of the light at each pixel.

By definition, an unlit material has no light contribution to affect - so afaik there is no accurate way to do what you want. There is no lighting normal and no contribution to fragment color.

Of course, you could experiment with “fake” alternative. For example, like multiplying the diffuse by the normal map - this will cause a constant variation to surface that does not change with viewer position.

Depending on what you want to achieve, this may be sufficient for your needs.

6

Try to multiply emissive color by normal map tangent z vector. This is cheap and does not depend on object rotation.

1 Like
7

Thanks to all your answer I think it will help me greatly

8

I know this is an old thread but how exactly do you do that : multiply emissive color by normal map tangent z vector

thanks

10

Take normal map sample. Take blue pin and plug that to multiply node with emissive color.