chore: checkpoint current workspace changes

docs/reference/NahidaUnity/Scripts/MaterialUpdater.cs

@@ -0,0 +1,33 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace Nahida
+{
+    public class MaterialUpdater : MonoBehaviour
+    {
+        [SerializeField]
+        private GameObject m_HeadBone;
+
+        [SerializeField]
+        private Vector3 m_HeadDirection = Vector3.up;
+
+        [SerializeField]
+        private List<SkinnedMeshRenderer> m_FaceRenderers;
+
+        private void Update()
+        {
+            if (m_FaceRenderers == null || m_HeadBone == null)
+            {
+                return;
+            }
+            Vector3 direction = m_HeadBone.transform.rotation * m_HeadDirection;
+            foreach (var renderer in m_FaceRenderers)
+            {
+                foreach (var material in renderer.materials)
+                {
+                    material.SetVector("_FaceDirection", direction);
+                }
+            }
+        }
+    }
+}