I'm trying to get a better understanding of the keyframe velocity dialog so that I can convert these values into Cubic Bezier pairs which could be used in code [for example in CSS cubicBezier(0,0,.3,.7)]
In After Effects each key has two properties. Influence and speed. By combining these two we see the bezier control point that determines the curve.
Influence is easy enough, it determines the X position of the control point. From 0-100% of the distance between keys. This maps directly to to the 0-1 range.
Speed is more difficult. The units depend on the property (pixels/second, percent/second, degrees/second)
The slope of the speed value is the angle of the line drawn between the control point and the key. This angle remains constant no matter what the influence is, and so determines the Y position of the control point.
My question is how do you calculate the slope angle? With that, you could use trig to get the resulting y position of the control point.
or if i'm on the totally wrong track...
How do you convert the speed value to the Y position of the control point?
feels like i'm getting closer to the answer... just not quite there....
-Mark