From Valve Developer Community
For HUDs in Garry's Mod, the parameter
$vertexalpha is needed in order to make the alpha parameter of
- Must be set to 1
- Must be set to 1 (This is not necessary on UnlitGeneric)
- The surface must be a displacement.
- You can use the "paint alpha" tool to paint the alpha.
There are some caveats.
- You can define a second base texture, but it will be invisible.
- Material renders as a translucent materials, and as such, suffers from the same sorting issues and caveats as materials with $translucent
To do: Are these commands shader-agnostic?