Hello It’s me again 
I found another problem with animations groups.
It’s kind of a merge of my 2 previous topics.
When you’re using goToFrame on an AnimationGroup where from and to frames are reversed, it doesn’t work as intended.
(I also tried with a negative speed ration and the result is the same)
Here is the same example that i put in my goToFrame topic but the from and to frames are reversed.
cc @Deltakosh
Unfortunately we are hitting the limit of the system here. The from and to are not supposed to be reversed AND then used to jump. This will imply a lot of check and work in the animation engine.
I would recommend in your case to have 2 animations (both from 0 to 30 but with key value inverted)
ok I may have another solution lol!
Here we are: Animation Examples | Babylon.js Playground
The idea is to stop all the animation to clear the caches and then play from the new key!
I tried your solution, but it actually didn’t work.
Indeed, when you’re stopping the animation and clearing all animatables, the goToFrame does nothing:
So when you’re playing your animation after that, it will start at frame 0
What about the idea I shared earlier with 2 sets of animations?
Also this then:
This is similar to what i actually have in my project.
I declare an animation with my from 0 to 50% my real animation, and from 50% to 100% the reversed animation.
But this is linked to some UI sliders witch are listening to the current frame of the animation.
In my case I have some asymmetric animations and some symmetric animations.
and that’s why i’d wanted to have a reversed animation in termes of frame for my symmetrics one
This seems good like that, i’ll try it, thanks 
