Standard Shader (Specular) gives incorrect overall shimmer to object

Unity Engine
1

Hey guys,

I’m using unity 5 beta (standard spec shader) and have a rock model with a diffuse and spec map. The spec map is mostly black (100% black) with some thin lines of shine on the rock edges.

The problem is that no matter how I treat the shader the rock always has a subtle white shimmer/halo around it in the areas that aren’t meant to be specular. The only way that removes it is to make the ambient source a color and not a skybox, but then it removes the specular altogether.

Is there a way to make sure its ONLY specular where its defined on the map?

Any help would be appreciated.

2

I had similar problems, and for me roughing up the non-specular areas helped quite a bit.

Rocks are pretty porous, and scatter light quite dramatically, I have a feeling your smoothness might be too high in your non-shiny areas.

3

I just dont understand it though, whats the point of the map if the spec is applied in other spots where it shouldnt be (completely black on the map)?

4

Seems like you don’t understand PBR very much.

You don’t just have a spec map. You have a spec map AND a so-called “roughness” map. The specular map controls the specular for surfaces facing straight into the camera. However, specular always approaches 100% on the edges (fresnel effect). This happens in real life, too! In fact, this bears repeating - everything has fresnel.
However, most of your specular detail does NOT go into the specular map. Actually, in your case the specular map should hardly deviate from 4% greyscale fill. Most of your detail instead goes into the roughness map. Essentially it defines how rough the surface is - the more rough the surface, the more the specular/reflection component becomes diffused and blurry. The less rough the surface, the more the specular/reflection component becomes sharp. Basically this is your “shininess” value. Rocks should be very rough.

5

Thanks Phobic,
If I have a spec map (mostly black) I can only insert it into the ‘Specular’ of the standard Spec shader OR I can insert it into the ‘Metallic’ of the Standard shader (this removes the Smoothness slider). Either way it gives me the automatic fresnel I’m trying to avoid.

Where am I meant to plug it in?

It even appears that the legacy shaders do not have a diffuse and specular slot. Should I make a rough fractal noise image in the non-specular areas and pure white in the shiny parts and slot it into the Standard Shader?

I’m looking for a barebones diffuse and spec material.

6

The smoothness/roughness map goes in the alpha channel of the specular texture :slight_smile:

7

“Barebones” diffuse and spec is pretty much a thing of the past (unless you go with Legacy Deferred Shading I think). PBR is the future. All hail the new PBR overlords.