Hi,
İ want to animate a rock thrown along a spline. And i think the ease option could use some more variation.
there is only
Ease Out
Ease In
Ease In-Out
but no Ease Out-In (fast,slow,fast) for example.
Or better yet just an Animation curve.
That is quick to implement and would help make it really flexible and actually useful for production right out of the box. What do you think?
I don’t think any easing happens when a rock is thrown through a ballistic trajectory.
Yes, technically air resistance causes the terminal velocity to be a little lower and hence the arrival angle be a little steeper, but in a frictionless sim, speed should be constant for a tossed rock.
i mean there is no way to emulate gravity. fast start slow at the apex fast on crash to the ground.
In the spirit of “What goes up must come down” 
or think bouncing ball.
when it hits the ground its fast and when it bounces up its still fast (the tangent is broken) and when it has reached the highest point it slows down again and starts speeding up etc..
Yes there is. Here’s the formula:
y = x * x
When you reach the ground, invert the velocity for a perfect bounce.
Google “ballistic trajectory” if any of what I write fails to make perfect sense.
NOW… if you just want easing, you can do that any number of ways by easing the input alpha or time parameter yourself, perhaps with a formula or like you suggested, with an AnimationCurve.
EDIT again: I think your problem is using Spline in the first place, since Spline is intended to be driven at a constant speed, regardless of where it is. Splines know nothing about dynamics. I would not use a spline for a trajectory because the formula for an actual trajectory is so simple: y = x * x
I need this for a ballistically thrown objects to a specific position.
rocks flung at the player to be precise. I don’t want to trust physics for that.
I also hacked it into the spline animate. It works but i think it could be a default implementation. Or as i said either select premade easings or use an animation curve