13. A computer-implemented method, comprising: receiving, in a media content authoring environment, a command to provide to a runtime environment a piece of media comprising a runtime-determined movement of a hierarchical object, the runtime-determined movement determined using the inverse kinematics procedure to move component objects of the hierarchical object in order to position an end effector on the hierarchical object nearer to a target location, the inverse kinematics procedure moving the component objects in response to receiving a variable identifying the end effector and the target location; and providing the piece of media for consumption by a consumption application in the runtime environment separate from the media content authoring environment, wherein the piece of media comprises the inverse kinematics procedure, wherein the inverse kinematics procedure uses both an authoring environment variable specified in the media content authoring environment and a runtime variable separately specified at runtime to determine a movement for the hierarchical object, and wherein the consumption application does not comprise the inverse kinematics procedure.
15. The method of claim 13 , wherein the runtime variable specifies the end-effector.