Split internal walls into more meshes.

Assets/Materials/Building/Strong_Wall.mat

@@ -77,12 +77,27 @@ Material:
         m_Texture: {fileID: 0}
         m_Scale: {x: 1, y: 1}
         m_Offset: {x: 0, y: 0}
+    - unity_Lightmaps:
+        m_Texture: {fileID: 0}
+        m_Scale: {x: 1, y: 1}
+        m_Offset: {x: 0, y: 0}
+    - unity_LightmapsInd:
+        m_Texture: {fileID: 0}
+        m_Scale: {x: 1, y: 1}
+        m_Offset: {x: 0, y: 0}
+    - unity_ShadowMasks:
+        m_Texture: {fileID: 0}
+        m_Scale: {x: 1, y: 1}
+        m_Offset: {x: 0, y: 0}
     m_Floats:
     - _AlphaClip: 0
     - _Blend: 0
     - _BumpScale: 1
+    - _ClearCoatMask: 0
+    - _ClearCoatSmoothness: 0
     - _Cull: 2
     - _Cutoff: 0.5
+    - _DetailAlbedoMapScale: 1
     - _DetailNormalMapScale: 1
     - _DstBlend: 0
     - _EnvironmentReflections: 1