portal with camera transformation

Assets/Escape Room Engine/Portal/Portal.cs

@@ -0,0 +1,36 @@
+using System;
+using UnityEngine;
+
+namespace Escape_Room_Engine.Portal
+{
+    public class Portal : MonoBehaviour
+    {
+        /// <summary>
+        /// The portal that is connected with this one.
+        /// </summary>
+        public Portal other;
+        /// <summary>
+        /// The main camera to take the position for the portal camera from.
+        /// </summary>
+        [SerializeField] private Transform playerCamera;
+        /// <summary>
+        /// The camera that will draw the view for this portal.
+        /// </summary>
+        [SerializeField] private Transform portalCamera;
+
+        private void Start()
+        {
+            // check whether the other portal is set up
+            if (!other || other.other != this) throw new Exception("Other Portal not set up correctly.");
+            // check whether the player camera is set up
+            if (!playerCamera) throw new Exception("No camera initialised.");
+        }
+
+        private void Update()
+        {
+            var portalCameraMatrix = transform.localToWorldMatrix * other.transform.worldToLocalMatrix *
+                                     playerCamera.localToWorldMatrix;
+            portalCamera.SetPositionAndRotation(portalCameraMatrix.GetPosition(), portalCameraMatrix.rotation);
+        }
+    }
+}