model_studio
...
This entity is Obsolete. Its use is discouraged, and it may only exist/function in older engine branches.
model_studio
is a point entity available in all Source games.
Leftover from Half-Life 2's early development (early 2001). It was a very old predecessor of prop entities (prop_static,prop_physics...ect.). This entity had only 2 keyvalues: angles and model directional path.
Note:This entity is only supported in the Half-Life 2's beta builds.