Advanced - Object Path Movers

If you're an original Unreal fan and have played through the original Unreal 1 campaign, you might be able to recall the long boat ride the player enjoys prior to entering the Nali Castle. It's the level right before the Nali Castle itself, NaliBoat.unr or more properly, Serpent's Canyon. If you're a little more keen on the features of Unreal Editor or movers, you might have noticed that there's really no way that the boat mover itself could go through the entire path, because it would be limited to only eight keyframes. However, it's not a normal mover. The boat is driven by PathPoint actors managed by an ObjectPath actor that essentially controls the relative path and velocity of the mover. In fact, no keyframes are ever set for ObjectPath movers.

Let's first look at the ObjectPath mover in Serpent's Canyon. Here are a few points to make note of:

• The mover is set to an InitialState of 'None'
• A damage-triggered mover triggers every PathPoint and their ObjectPath, but not the mover itself
• The ObjectPath references the mover and contains the final rotation for the mover (the orientation the mover will have after the final PathPoint)
• PathPoints act as key points in a similar way to InterpolationPoints
• MoverGlideType is set to MV_MoveByTime

Important PathPoint properties:

sequence_Number - The ordered number of points, like InterpolationPoint's Position

curveSpeed - The speed of the mover at this point relative to the next PathPoint, which in turn modifies the shape of the path

speedU - Scaled speed (for instance, if speedU equals some integer n, the object travels to the next point in 1/n seconds)

The similarity between these paths and interpolation paths is that they are both bezier segments. So these aren't liek keyframes where objects travel along a linear path.

The following video instructs you on how to make a basic ObjectPath mover: