Animation : setting AnimationState.normalizedTime clears cross fade

Unity Engine
1

This code snaps immediately to frame 0 of animation B:

//start
animation.Play("A");

//later
animation.CrossFade("B", 0.2f);
animation["B"].speed = 0.0f; //Drive the progress in code
animation["B"].normalizedTime = 0.0f;

//update (later still)
animation["B"].normalizedTime  = someExternalVariable;

Removing the sets to normalizedTime however causes it to crossfade over 0.2 seconds to the first frame of B:

//start
animation.Play("A");

//later
animation.CrossFade("B", 0.2f);
animation["B"].speed = 0.0f; //Drive the progress in code
//animation["B"].normalizedTime = 0.0f;

//update (later still)
//animation["B"].normalizedTime  = someExternalVariable;

This seems like a bug. How can I cross fade to a driven animation?

Thanks

Dan

2

Case 394893