Is there a way to have a material be (semi-) transparent in the viewport with solid display? Would love to set an alpha value on the “Viewport display” diffuse.
What do you mean by transparent with solid display?
You can make a object look transparent by cheking “Transparent” in the tab “display” of the Object Properties Menu.
In 2.79 I could have this in the viewport, with the alpha set per material
With 2.8 it is always fully opaque, I can’t find a way to set the alpha.
Unless I set the whole scene to transparent, but that’s not what I want, I want just this material to be semi-transparent. I also can’t see the transparent option you mention in the object properties?