Animation Looks Different in the Engine
Motion plays differently than in Maya or Blender
Also known as: Animation different in Unreal · Animation different in Unity · Animation export wrong · Animation fps mismatch · Animation compression artifacts · Animation scale wrong import
Quick answer
Animation looks different in the engine than in your 3D tool when the frame rate, scale, skeleton or compression do not match. Export at the project's frame rate and bake the animation so every frame has keys, use the same skeleton and bind pose in both places, check that the units and scale are correct, and reduce lossy animation compression for key clips. Root motion and bone axis settings also change how the movement plays.
How to fix it
Test with a simple animation first, such as a bone moving along a line, to isolate the problem. Check the interpolation: constraints, IK and custom rigs have to be baked, since the engine only reads bone transforms. Compare the animation frame by frame with the original, and look at the first and last frames. Settings for import, such as sample rate and the root bone, are saved in the animation asset, and should be consistent across the project.
Tools that use Animation Looks Different in the Engine
See also
FBX
The standard 3D exchange format for games
Animation Frame Rates (24, 30, 60 fps)
Which frame rate to animate and export at
Animation Compression
Reducing animation memory with a small error
Root Motion
Movement driven by the animation, not the controller
Bind Pose
The neutral pose a mesh is skinned in
Animation Retargeting
Transferring animation between skeletons