linking keyframes from 2 layers or nulls to make strong track

[Jon Simpson]

This reads like an expression solution but I am just learning that myself.

[Hanna Dean]

what plugin i can get that does this mate

[Walter Soyka]

[hanna dean] “is it possible to link 1 3d image layer to 2 track null points to keep the image still without shaking ?”

It’s possible to determine the midpoint of two points; whether the midpoint is still depends on the tracked points.

Here’s the expression. Alt+click on the position stopwatch of the layer you’d to set at the midpoint between Null 1 and Null 2. (The formula for midpoint is just the average of each of the two points coordinates.)

null1Pos = thisComp.layer("Null 1").transform.position;
null2Pos = thisComp.layer("Null 2").transform.position;

midPointPos = [ (null1Pos[0] + null2Pos[0]) / 2, (null1Pos[1] + null2Pos[1]) / 2, (null1Pos[2] + null2Pos[2] ) / 2 ];

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
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