Initializes the entity's physics object as a physics shadow. Physics shadows can react to the environment physically (see the arguments to the function), and can push other physics objects around, but are ultimately constrained to the entity's position and angles: the physics object will attempt to return to the entity's coordinates every simulation tick.

Internally, this creates a new physics object, copies the properties of the current physics object to it if one exists, and replaces the entity's physics object with the shadow. This is used internally for Player and NPC physics objects, certain HL2 entities such as the crane and barnacle tongue, parented physics entities, etc.

A physics shadow can be used to have static physics entities that never move by setting both arguments to false.

The created physics object will depend on the entity's solidity SOLID_NONE will not create a physics object, SOLID_BBOX will create a Axis-Aligned BBox one, SOLID_OBB will create Orientated Bounding Box one, and anything else will use the models' physics mesh.

See also ShadowControlParams structure.