InstancedMesh: Add not about material sharing.

docs/api/en/objects/InstancedMesh.html

@@ -17,6 +17,9 @@
 		objects with the same geometry and material but with different world transformations. The usage of [name] will help you
 		to reduce the number of draw calls and thus improve the overall rendering performance in your application.
 		</p>
+		<p>
+		The current implementation requires that materials are not shared between [name] and other 3D objects.
+		</p>
 
 		<h3>Examples</h3>
 

docs/api/zh/objects/InstancedMesh.html

@@ -17,6 +17,9 @@
 		objects with the same geometry and material but with different world transformations. The usage of [name] will help you
 		to reduce the number of draw calls and thus improve the overall rendering performance in your application.
 		</p>
+		<p>
+		The current implementation requires that materials are not shared between [name] and other 3D objects.
+		</p>
 
 		<h3>Examples</h3>