Previously the HUD fading in/out would also recenter the hmd sensor and the avatar, which caused many problems including:
* The user's view could shift vertically.
* Your avatar would briefly go into t-pose
* other users would see your avatar go into t-pose.
Now we now move the UI sphere instead, which results in a much smoother experience.
MyAvatar: added hasDriveInput method.
OverlayConductor:
* removed avatar and sensor reset, instead the overlay's modelTransform is changed.
* revived STANDING mode, which is active if myAvatar->getClearOverlayWhenDriving() is true and you are wearing an HMD.
* SITTING & FLAT mode should be unchanged.
* Instead of using avatar velocity to fade out/fade in the hud, We use the presense or absanse of avatar drive input.
* Additionally, we check distance to the UI sphere, and quickly recenter the hud if the users head is too close to the actual hud sphere.
CompositorHelper:
* Bug fixes for ray picks not using the modelTransform.
HmdDisplayPlugin:
* Bug fixes for rendering not using the modelTransform.
In the unlikely event you hit 90htz in non-threaded present mode, you will have perfect tracking and latency.
This verifies that there are no other sources of tracking or rendering latency, other then the ones we already know about.
* Application::idle, physics and avatar processing are tracked
* Application::paintGL frameNumber payload is tracked
* OpenGLDisplayPlugin::present is profiled with corresponding frameNumber payload
* Added color and payload support to Nsight ProfileRange class.
Before this fix, a script could call into HMD.getHUDLookAtPosition2D() while the app was shutting down, which in turn would call
getHeadPose() on the currently active display plugin. This call could cause a crash within the openvr plugin, because the SDK was either shutdown, or in the process of shutting down on the main thread.
This fixes this by spliting the previous DisplayPlugin::getHeadPose(int) into two parts:
* updateHeadPose(int) which is only called once a frame and only by the main thread.
* getHeadPose() which is thread-safe and will return a cached copy of the hmd pose sampled by the last updateHeadPose.
