From Garry's Mod
Sets the player which the current undo block belongs to
The player responsible for undoing the block
This example creates a prop_physics, and adds it to the players undo list.
prop = ents.Create("prop_physics") prop:SetModel("models/props_junk/wood_crate001a.mdl") prop:Spawn() undo.Create("prop") undo.AddEntity(prop) undo.SetPlayer(ply) undo.Finish()