Was try to using locked target to keep my subject "in frame' rather than a corresponding animation to rotate camera (QI calls camera._getViewMatrix() for meshes that are locked on to cameras as they are moved). It is much more accurate. Problem is I want to discontinue at one point. When I do, camera jumps back to before. Want it to stay where I left off. Tried this, but not what I want:
// unplug hero from sceneCamera
var tmpScale = BABYLON.Vector3.Zero();
var tmpTrans = BABYLON.Vector3.Zero();
var tmpRotQ = new BABYLON.Quaternion();
sceneCamera._viewMatrix.decompose(tmpScale, tmpRotQ, tmpTrans);
sceneCamera.rotation = tmpRotQ.toEulerAngles();
sceneCamera.lockedTarget = null;