Added versioning code for ShadowCaster2D

Author: unity-cchu

com.unity.render-pipelines.universal/Runtime/2D/Shadows/ShadowCaster2D.cs

@@ -13,6 +13,9 @@ namespace UnityEngine.Experimental.Rendering.Universal
     [AddComponentMenu("Rendering/2D/Shadow Caster 2D (Experimental)")]
     public class ShadowCaster2D : ShadowCasterGroup2D
     {
+        const int k_CurrentVersion = 1;
+        [SerializeField] int m_Version = 0;
+
         [SerializeField] bool m_HasRenderer = false;
         [SerializeField] bool m_UseRendererSilhouette = true;
         [SerializeField] bool m_CastsShadows = true;
@@ -22,6 +25,7 @@ public class ShadowCaster2D : ShadowCasterGroup2D
         [SerializeField] int m_ShapePathHash = 0;
         [SerializeField] Mesh m_Mesh;
         [SerializeField] int m_InstanceId;
+        
 
         internal ShadowCasterGroup2D m_ShadowCasterGroup = null;
         internal ShadowCasterGroup2D m_PreviousShadowCasterGroup = null;
@@ -132,11 +136,12 @@ private void Awake()
 
         protected void OnEnable()
         {
-            if (m_Mesh == null || m_InstanceId != GetInstanceID())
+            if (m_Mesh == null || m_InstanceId != GetInstanceID() || m_Version != k_CurrentVersion)
             {
                 m_Mesh = new Mesh();
                 m_ProjectedBoundingSphere = ShadowUtility.GenerateShadowMesh(m_Mesh, m_ShapePath);
                 m_InstanceId = GetInstanceID();
+                m_Version = k_CurrentVersion;
             }
 
             m_ShadowCasterGroup = null;