Importing Fast Moving Animation Result In Wrong Interpolated Animation

Hi all.

I’m having an annoying issue when an animation is imported to Persona.
The animation is a fast sword stab and is all fine in 3DMax, but rather of explain it better I’ll show you the problem.

This is the original animation. (Play rate at 1/4 to watch better the movement)

And this is the same animation in Persona.

As you can see the sword interpolate the movement between the fast moving frames.

How can I fix this problem?

When I press play, I get “This video is private” for both videos.

Sorry, you can play it now

I had a bug like that in the past with my custom skeleton, the weapon bone was a child of the right hand so whenever i added fast/heavy motion to just the weapon bone it started to break, only solution was to parent the weaponbone to the root instead :confused:

How is your hierachy setup? Weapon bone a child of the hand?

No, the setup is a biped from 3DMax and the props bones are child of the root.

I must say that the sword mesh is not part of the character.
It’s another mesh which follow the socket added to the prop bone which represent the sword.

The prop bone, the socket and the mesh sword have the same identically rotation.

First thing I’d do here is to import the FBX back into Max to see if the problem lies with the exported animation. If so, then at least you know if it’s an exporting problem or actually just in UE4.

So fixing it, one thing you can try, unless you already did, when you export try and check Resample All. Though I found it’s generally better to keep it unchecked, but it’s something you can try. I have had one or two cases where checking it produced better results, compared to unchecking it. If you currently have it checked, try unchecking it then in stead.

The other thing you might try, which is basically what I do with my faster animations, is to give it more frames, so it’s kinda slower than it ultimately would be. So lets say your move is 3 frames total where you create the arc of the sword slash and that is the speed you want. That is quite extreme for a full arc, in stead make it 5 frames… or whatever. So you cover more points on the arc with actual key frames. Basically slow everything down by a little bit. Then in UE4 you can just speed it back up, but you have more frames to cover the poses and less chance of interpolation error.

I have to admit that I have never seen this happen with my own animations, but I have created them with this (slow down) method from the start, because I know game engines do their interpolation and I wanna be sure to get something accurate, so it’s possible I just dodged the problem like that. Or who knows, it might be something totally different creating that problem that I have not come across before. So I just wanted to mention my thoughts, maybe it helps you out.

Thanks a lot Obihb, the idea of reset the speed of the animation and adjust into the UE4 is great, I’ll try it right now, I think this will avoid the problem.

I must say I had tried to check and uncheck the “resample all”, but nothing different happend.

I’ll try this solution and report my results