add unity doc.

unity/PICO-Unity-Integration-SDK-release_3.4.0/Runtime/BuildingBlocks/PXR_ObjectTrackingBlock.cs

@@ -0,0 +1,103 @@
+using System.Collections.Generic;
+using Unity.XR.PXR;
+using UnityEngine;
+using UnityEngine.Rendering;
+
+public class PXR_ObjectTrackingBlock : MonoBehaviour
+{
+    private Transform objectTrackers;
+    private bool updateOT = true;
+    private int objectTrackersMaxNum = 3;
+    int DeviceCount = 1;
+    List<long> trackerIds = new List<long>();
+   
+
+    // Start is called before the first frame update
+    void Start()
+    {
+        objectTrackers = transform;
+        for (int i = 0; i < objectTrackersMaxNum; i++)
+        {
+            GameObject ga = GameObject.CreatePrimitive(PrimitiveType.Cube);
+            ga.transform.parent = objectTrackers;
+            ga.transform.localScale = Vector3.one * 0f;
+#if UNITY_6000_0_OR_NEWER
+            if (GraphicsSettings.defaultRenderPipeline != null)
+#else
+            if (GraphicsSettings.renderPipelineAsset != null)
+#endif
+            {
+                Material material = new Material(Shader.Find("Universal Render Pipeline/Lit"));
+                Renderer renderer = ga.GetComponent<Renderer>();
+                if (renderer != null)
+                {
+                    renderer.sharedMaterial = material;
+                }
+            }
+        }
+        int res = -1;
+#if PICO_OPENXR_SDK
+#else
+             PXR_MotionTracking.RequestMotionTrackerCompleteAction += RequestMotionTrackerComplete;
+             res = PXR_MotionTracking.CheckMotionTrackerNumber(MotionTrackerNum.TWO);
+#endif
+        
+        
+        if (res == 0)
+        {
+            objectTrackers.gameObject.SetActive(true);
+           
+        }
+    }
+    private void RequestMotionTrackerComplete(RequestMotionTrackerCompleteEventData obj)
+    {
+        DeviceCount = (int)obj.trackerCount;
+        for (int i = 0; i < DeviceCount; i++)
+        {
+            trackerIds.Add(obj.trackerIds[i]);
+        }
+        
+        updateOT = true;
+    }
+    // Update is called once per frame
+    void Update()
+    {
+#if UNITY_ANDROID
+       
+        for (int i = 0; i < objectTrackersMaxNum; i++)
+        {
+            var child = objectTrackers.GetChild(i);
+            if (child)
+            {
+                child.localScale = Vector3.zero;
+            }
+        }
+
+        // Update motiontrackers pose.
+        if (updateOT )
+        {
+            MotionTrackerLocation location = new MotionTrackerLocation();
+            for (int i = 0; i < trackerIds.Count; i++)
+            {
+                bool isValidPose = false;
+                int result = -1;
+#if PICO_OPENXR_SDK
+#else
+                result = PXR_MotionTracking.GetMotionTrackerLocation(trackerIds[i], ref location, ref isValidPose);
+#endif
+                // if the return is successful
+                if (result == 0)
+                {
+                    var child = objectTrackers.GetChild(i);
+                    if (child)
+                    {
+                        child.localPosition = location.pose.Position.ToVector3();
+                        child.localRotation = location.pose.Orientation.ToQuat();
+                        child.localScale = Vector3.one * 0.1f;
+                    }
+                }
+            }
+        }
+#endif
+    }
+}