Fixes issue where motion blur would not display for certain objects intermittently due to uninitialized parameters in the ObjectKey struct causing the motion object map look-up to fail and for motion parameters to be reset to default, disabling the effect for the given objects. Authored by Apple: Michael Parkin-White Co-authored-by: Michael Parkin-White <mparkinwhite@apple.com> Pull Request: https://projects.blender.org/blender/blender/pulls/117560