CNAT - Contact Attachment

In multiple places the engine uses ContactAttachment values (a bitmask) to manage the orientation of objects and processes. For example, a vertex of an object can have the CNAT bit left. If that object has ContactCalls activated, the engine calls on every contact of that vertex with the landscape the object script function ContactLeft. CNAT values are composed of the following bits:
CNAT Description
CNAT_Left Direction: Left
CNAT_Right Direction: Right
CNAT_Top Direction: Up
CNAT_Bottom Direction: Down
CNAT_Center Direction: Center (not for attachment)
CNAT_MultiAttach Special flag: new attachment behaviour for objects with the same direction value at several vertices.
CNAT_NoCollision Extra flag: non-colliding vertex
CNAT_PhaseHalfVehicle Extra flag: Entirely suppress collisions with HalfVehicle
A vertex can have multiple CNAT values, they can be combined them with the | operator. Example:
Attach = CNAT_Bottom | CNAT_Left
Newton, 2013-11