I’ve been a little confused about the function of clear coat. In HDRP Lit, it behaves as expected, with a texture mask you can supply and an intensity slider.
But when making a custom shader in shader graph, and enabling “Clear Coat”, the shader will always make surfaces reflective regardless of the value you input into “Coat Mask” (even at flat 0, the surface is always reflective). In HDRP Lit, it does not behave this way, with the surface reflection scaling with the slider and disabled at 0.
How can I make the clear coat in my shader behave like it does in Lit?
Unity 2022.3.48f1
HDRP 14.0.11
(to be clear, the “Coat Mask” defaults to a black texture, and I’ve also debugged it without any textures and just raw values - 0 still causes the surface to be reflective.)
I did a quick try with Unity 2022.3.49f1, and don’t have your issue.
In the bellow image, the left plane has a HDRP/Lit material with coat mask set to 1, and the right one has the displayed shadergraph applied. Even with a strength set to 1, the default black texture makes the coat inactive, leaving only the rough surface visible.
Maybe something else in the shader is the source of the shininess ?
Nope - it’s definitely coming from the clear coat. I tested on an empty shader graph with metallic and smoothness set to 0, and the surface is rough until I enable clear coat, at which point it becomes reflective.
Interestingly enough however, I discovered the surface returns to being rough if I add a very tiny amount to the clear coat, so it’s a non-zero (and from there it scales normally). But setting clear coat to a flat 0 makes the surface reflective. Maybe there’s some default value that the coat is resetting to that I’m not aware of?
Did you tried with 2022.3.49f1 ? Maybe it is some bug that got fixed.
I definitively don’t have this behaviour on my side, if you can still reproduce it with the latest version, it might be worth to submit a bug report with your project files.
After playing around with it more, I discovered this issue only appears in Forward only rendering. Deferred doesn’t have this issue. Can you try again with these settings?
It have the exact same rendering using deferred or forward on my side 
Alright, last desperation - here is the project repro: Dropbox
Running on Unity 2022.3.49f1, HDRP 14.0.11
Steps to reproduce:
- Open “Assets/OutdoorsScene.unity”
- Observe the plane - it has a Shader Graph material with Smoothness and Metallic at 0, and a float plugged into Coat Mask. Despite the float value being 0, the plane still reflects the cube.
- Change the coat mask value in the material to a small non-zero value (0.001) and observe how the plane stops reflecting the cube.
- Return the float value to 0 to see the plane reflecting the cube again. Go into “Assets/Settings/HDRenderPipelineAsset.asset”, and change Lit Shader Mode from Forward Only to Deferred Only, and observe how the issue is once again gone, with the plane no longer reflecting the cube.
Ok, now I repro, and narrowed down the issue to be related to the screen space reflection.
In my project I just used planar reflection, naively thinking it would just be the same.
So, a shadergraph with clear coat, even set to 0, does produce SS reflection, this is probably a bug.
Do you mind submiting the bug with the bug reporting tool including your project ?
Done, thank you! I’ll post an update once a fix is deployed.
