Interpolation understanding


I started working on my second project. It’s a cosmic animation where I generally plan to work with light, sound and camera view techniques.

And now I am stuck at camera view. I need it to start moving slowly at beginning, then pass some space and slowly stops at the end. So it goes like this:
0s-5s: Camera start moving forward slowly.
5s-15s: Camera is now moving at some general speed.
15s-20s: It stops slowly.

I created two keyframes at 0s and 20s. Then changed both “Origin” waypoints of camera-view plugin to “Ease In/Ease Out”. And it works perfectly from 5s to 20s (it stops slowly as I want), but it does not start slowly. I tried converting waypoints to the TCB and experiment with “bias” sub-parameter, but it still behaves not like “Ease Out” at the end.
I use the camera-view plugin from Genete and Zelgadis.

So can please someone clarify why “Ease In” waypoint don’t behave like “Ease Out” one? How can I achieve the above example with Synfig?

hello, good question indeed,

ease in out has you talk about is not so intuitive … but possible!

Waypoint - ease in-out.png
(artistic view of graph and timeline panel composed with gimp)

added to wiki : … _Waypoints

Totally confused now :open_mouth:

Maybe if you share a sample file (just a circle moving with the same waypoints) that illustrate the problem, we would see it clearer.

Well… I am stupid :frowning: I only converted one waypoint (the last one) to “Ease In/Out” but didn’t do the same to the first one. So I get the slow-down effect at the end, but not at the start.

I am very sorry I brought some confusion here… Damn it, I’ll try to be more careful when animating. Thanks everyone and especially d.j.a.y! When I saw the attachment I checked is there an “Ease In/Out” waypoint at the beginning and discovered the problem.