Resolved Right way to disable and skip "Specular Highlights" and "Environment Reflections" on custom shaders?

Many of Unity's built in shaders, like the URP/Lit shader, have checkboxes to entirely disable Specular Highlights and Environment Reflections and I'd like to know if Shader Graph can prune those two features to the same degree. Intuitively, zeroing values out would seem like something that could be detected and pruned at build-time, but I'd rather be certain.



It's easy enough to set the smoothness, specular, and metallic parameters to zero, or even to delete the nodes from the fragment shader displayed on the graph, but which if either of these will definitively cut those layers from the shader? If zeroing is enough, will it still be recognized with a boolean attached even if it's passing the same zeroed value?

So to rephrase the question, when, if ever, will Shader Graph entirely skip its specular and reflection layers? Is environment reflection accessible in the same way to begin with?

 

also interested

 

You can use shader keywords:
_SPECULARHIGHLIGHTS_OFF
_ENVIRONMENTREFLECTIONS_OFF
as boolean keywords. Set them as local shader features in fragment and make sure to check the "exposed" checkbox to allow toggling in the editor. Note enabling these keywords actually turns these features off.
They don't need to exist in the graph itself, just in the properties panel.

 

I've done this in a shadergraph (in 2021.3.20f1) , but sometimes it seems like a material will ignore one of the settings and randomly flip it. (The inspector for the material will show "Environment Reflections Off" as checked, but reflections will show. Is there some way other scripts/materials could be interfering with this? (There are no scripts on my end that would be setting either keyword). Maybe skybox stuff?

 

Check the generated shader code and see what keywords are being set. I'd start there.

 

For clarity, here's the pattern I use in Shadergraph. The keyword reference may fall out of sync with your display name so double check that those are identical to what was posted above. I use negative tense names to match the actual toggle state.