I have a Blender 2.8 project with a mesh and an animated camera. Both assets are extracted from a video clip. I can overlay the animation (camera moving around the mesh) with the original video in Blender and they line up correctly.
I imported the mesh and camera animation to Unreal 4.23 as fbx. The resulting animation is almost correct, but when it’s overlaid with the original video it’s easy to see it’s slightly wrong. They don’t ‘lock’ together.
As a test I rendered a clip of just the mesh& camera animation from both Blender and Unreal. Then I blended these videos together using difference mode (subtract one from the other) to make it easier to see the difference. They clearly do not align correctly. See it here -
Any idea what could be going on here? I’ve triple checked that the correct frames are being used so something else seems to be going on. When looking at the keyframe values in Unreal they are even slightly different, close but different (and more that rounding errors). It’s as if some kind of interpolation is occurring, or a very slight scaling perhaps. When I import the camera fbx it always comes in with a keyframed scale of 100 which I need to reset. Don’t know if that could be connected.