Also moved Rig::updateAnimations() now occurs after
Rig::updateFromHeadParameters() and Rig::updateFromHandParameters().
This should remove a frame of lag for head and hand IK targets.
Rig::updateFromEyeParameters() occurs after Rig::updateAnimations().
But now the eye JointStates are re-computed, this is the actual
fix for the local eye tracking issue.
The IK was assiming that the "Hips" bone index was always 0.
This was not the case for Owen. Now we lookup the Hips index
and cache it for use during the hipsOffset computation.
MyAvatar: refactored updateFromHMDSensorMatrix() a bit by splitting it into several methods, because
it was getting quite large and becoming hard to follow.
* beginStraighteningLean() - can be called when we would like to trigger a re-centering action.
* shouldBeginStraighteningLean() - contains some of the logic to decide if we should begin a re-centering action.
for now it encapulates the capsule check.
* processStraighteningLean() - performs the actual re-centering calculation.
New code was added to MyAvatar::updateFromHMDSensorMatrix() to trigger re-centering when the avatar speed rises
over a threshold.
Secondly the Rig::computeMotionAnimationState() state machine for animGraph added a state change hysteresis
of 100ms. This hysteresis should help smooth over two issues.
1) When the delta position is 0, because the physics timestep was not evaluated.
2) During re-centering due to desired motion, the avatar velocity can fluctuate causing undesired animation state fluctuation.
Only the JointState._defaultTranslation needs to be multiplied
by the unitScale in JointState::translationIsDefault(). This
was incorrectly flagging some non-animated joints as animated.
