[quote:3q3643ym]So is the player/terrain moving or is it more like a carpet being pulled beneath the object to imply motion?
The player is moving like normal when it's X position is between 200 and 440, and when the player passes either of those boundaries he is kept from moving and the terrain is moved (like a carpet as you say).
[quote:3q3643ym]What is this TimeDelta concept?
TimeDelta is the difference of time from one frame to another.
[quote:3q3643ym]I'm not used to the "." between events - is that merely a separator in the line or is that fundamental code?
Fundemental code. See "Object expressions" in the wiki http://sourceforge.net/apps/mediawiki/construct/index.php?title=Expressions
[quote:3q3643ym]Terrain: Set X to Terrain.X-player[Platform].VectorX*TimeDelta
Player: Set X to 440+player[Platform].VectorX*TimeDelta
I'm using the simple formula "rate X time = distance".
The first line moves the terrain at the same speed but opposite direction as the player. And the second moves the player to the boundary plus any any movement the player was going to avoid jitter. Try setting the second line to just 440 to see the difference.