Fall

fall simply causes an actor to begin falling to the ground. fall is also responsible for updating an actor's htcgg, htfloorz, and htceilingz values as well as applying impact damage to monsters, including spawning JIBS6 and playing the THUD sound.

In a sector with a parallaxed ceiling with a palette of 0 and a texture of MOONSKY1 or BIGORBIT1, fall operates with gravity reduced to 1/6th of normal. If instead the floor meets these criteria, fall operates as indicated above but without any gravity at all.