Hello. I would like to use my custom mesh and apply a widget texture or something so it works as 3D widget. Is that possible?
Perhaps you could try this:
Put a Scenecapture2D in your level, point it at a blueprint that has a widget component inside of it.
Then map the scenecapture2d file to a masked material that has the alpha flipped.
Then simply apply this scenecapture material to whatever 3d model you want in the scene.
Good solution. But remember that SceneCapture2D is a performance hog.