Only apply default head height if not managed by device

XRTK-Core/Packages/com.xrtk.core/Runtime/Interfaces/CameraSystem/IMixedRealityCameraDataProvider.cs

@@ -18,6 +18,13 @@ public interface IMixedRealityCameraDataProvider : IMixedRealityDataProvider
         /// </summary>
         bool IsStereoscopic { get; }
 
+        /// <summary>
+        /// Is the head height, and thus the camera y-position, managed by the device itself?
+        /// If true, the <see cref="DefaultHeadHeight"/> setting is ignored and has no effect
+        /// on camera positioning.
+        /// </summary>
+        bool HeadHeightIsManagedByDevice { get; }
+
         /// <summary>
         /// The <see cref="IMixedRealityCameraRig"/> reference for this data provider.
         /// </summary>

XRTK-Core/Packages/com.xrtk.core/Runtime/Providers/CameraSystem/BaseCameraDataProvider.cs

@@ -3,6 +3,7 @@
 
 using System;
 using UnityEngine;
+using UnityEngine.XR;
 using XRTK.Definitions.CameraSystem;
 using XRTK.Extensions;
 using XRTK.Interfaces.CameraSystem;
@@ -85,6 +86,9 @@ public BaseCameraDataProvider(string name, uint priority, BaseMixedRealityCamera
         /// <inheritdoc />
         public virtual bool IsStereoscopic => CameraRig.PlayerCamera.stereoEnabled;
 
+        /// <inheritdoc />
+        public virtual bool HeadHeightIsManagedByDevice => XRDevice.isPresent;
+
         /// <inheritdoc />
         public IMixedRealityCameraRig CameraRig { get; private set; }
 
@@ -239,7 +243,11 @@ public override void Destroy()
         /// </summary>
         protected virtual void ApplySettingsForDefaultHeadHeight()
         {
-            HeadHeight = DefaultHeadHeight;
+            if (!HeadHeightIsManagedByDevice)
+            {
+                HeadHeight = DefaultHeadHeight;
+            }
+
             ResetRigTransforms();
             SyncRigTransforms();
         }
@@ -274,8 +282,10 @@ protected virtual void ResetRigTransforms()
         {
             CameraRig.PlayspaceTransform.position = Vector3.zero;
             CameraRig.PlayspaceTransform.rotation = Quaternion.identity;
-            // If the camera is a 2d camera when we can adjust the camera's height to match the head height.
+
+            // If the camera is a 2d camera then we can adjust the camera's height to match the head height.
             CameraRig.CameraTransform.position = IsStereoscopic ? Vector3.zero : new Vector3(0f, HeadHeight, 0f);
+
             CameraRig.CameraTransform.rotation = Quaternion.identity;
             CameraRig.BodyTransform.position = Vector3.zero;
             CameraRig.BodyTransform.rotation = Quaternion.identity;