View Full Version : Relativity expressions only evaluate one item in a scene

Kevin Kipper
02-20-2019, 10:01 PM
Hi Everyone,

I have a LW2018.0.6 scene in which 3 items have Relativity applied as a motion modifier.

The relativity expression was created with the Dr.MoveVec Professor under the Special Functions section.

It generates a simple expression "MOVEVEC(X(a3_speed_ctl,t),t)" in which the "a3_speed_ctl" X channel contains my meters per second value.

This works absolutely fine in a proof of concept scene, containing 3 null items with relativity applied and 3 null items as the controllers.

However, when I create the same expressions in a different scene for the shot I'm working on, only one of the items with relativity will evaluate. I have to disable the other two items with Relativity applied in order to see one item get properly evaluated.

Any ideas on why this happens and how to correct it?

I've tried loading a proof of concept scene into my shot scene and the same thing happens. I've tried to recreate the expression from scratch and the same thing happens.

Thanks for your help and ideas.



02-22-2019, 10:56 PM
If I understand what you're trying to do, this seems to work for me in LW2018.0.6.

Attached is a simple scene with three clones of a SunBall object and three clones of ControllerNull. Each SunBall is rotated to a different Heading (the direction for MOVEVEC so they spread apart over time), and each ControllerNull has a different envelope in X to control the forward (Z direction) motion of the associated SunBall. Each SunBall seems to move appropriately to the X Position of it's associated ControllerNull.

MOV file: 144212

Good luck!

02-23-2019, 09:09 AM
I forgot to mention: When I cloned the SunBall object with the Relativity equation already in place, I had to manually change the controller Object's "index" number. So, for SunBall (1), the Relativity expression refers to ControllerNull(1), which was cloned to SunBalls 2 and 3. I brought up Relativity and manually changed SunBall (2) to reference ControllerNull(2), and SunBall (3) was changed to ControllerNull (3).