Object update order (split from earlier thread)

The movie being talked about is available as a projector here:[url=“http://darken.spark.lithotech.co.nz/pier_island_02.zip”]


You might notice that the trees are always a frame behind their shadow and the ground.

I’m updating the tree location based on a point on the ground tile, but the trees are being updated before the ground - hence they don’t come back into line until the ground stops moving.

How do you change the order of update? The trees and the ground are objects with classes, but they’re using enterframe methods inside each class rather than any interval-type stuff. Would setting an interval fix this? I haven’t used interval yet, but have a vague idea of what it does.