View Full Version : Bracketed Expressions in Expressions?

11-26-2004, 03:32 PM
I'm trying to work out a way to animate a series of flippers, sort of like a brine-shrimp ("sea monkey") would have. I need to be able to globally control them so that I can speed them up and slow them down, but still keep them in synchronization so that the wave of paddling passes down the body in a coordinated fashion. The legs will also, like a brine shrimp, vary slightly in size from one end of the creature to the other, which will mean that I will have to alter the degree of bend interactively to keep them from overlapping each other (I think). I'm trying to write series of related expressions to handle this, referencing the Y-Position of several nulls to allow me to interactively affect the main elements of a sine function, unfortunately, a pretty necessary time offset isn't being accepted.
This takes the form of referencing the main sine function (call it "Sine1"), with the additional input of a Time call based on the Y Position of a null, so that it would look like this:
[Sine1, Frame + [FrameOffset.Position.Y]]
where "FrameOffset" is the name of the regulating null. I actually managed to crash LW with that. Any suggestions? Please keep in mind that this will be my first attempt to use expressions in any way beyond tutorials.

I've enclosed my working file (minus the part that caused the blowup), so you can see what I'm aiming for.....