Procedures

For object activity the engine offers various standard procedures which perform typical physical behaviour. In procedure WALK, for instance, the activity automatically changes to "Jump" if the ground under the feet is lost.

Procedure	Description	Behaviour	CNAT
nil	No procedure	Only gravitational effects or attachment as specified in the activity.	Action.Attach
DFA_WALK	Walking	According to current ComDir.	CNAT_Bottom
DFA_FLIGHT	Free fall	Only gravitational effects	CNAT_None
DFA_KNEEL	Getting up	Behaviour according to activity.	CNAT_Bottom
DFA_SCALE	Scaling a wall	According to current ComDir.	CNAT_Left/Right
DFA_HANGLE	Climbing on the ceiling	According to current ComDir.	CNAT_Top
DFA_DIG	Dig	According to current ComDir. With Data=1 material chunks are dug free.	CNAT_None
DFA_SWIM	Swimming	According to current ComDir.	CNAT_None
DFA_THROW	Throw	Behaviour according to activity.	CNAT_Bottom
DFA_PUSH	Pushing	Pushes the target object according to ComDir.	CNAT_Bottom
DFA_LIFT	Lifting	Lifts the target object according to ComDir.	CNAT_None
DFA_FLOAT	Floating in mid-air	According to current ComDir.	CNAT_None
DFA_ATTACH	Attachment to another object	Adjusts object position at vertex a to the position of vertex b of the target object. a and b are the two low bytes of ActionData (see SetActionData for an example).	CNAT_None
DFA_CONNECT	Line connections	Only line objects. Connects target object 1 and target object 2.	CNAT_None
DFA_PULL	Pulling	Pulls the target object according to ComDir.	CNAT_Bottom

Procedures are hardcoded in the engine and are from older times in which is was not yet possible to implement the same functionality in script. Most procedures represent highly complex behaviour which is useful only for clonks.