update docs for material stencilWrite

docs/api/en/materials/Material.html

@@ -125,7 +125,7 @@
 
 		<h3>[property:Boolean stencilWrite]</h3>
 		<p>
-		Whether rendering this material has any effect on the stencil buffer. Default is *false*.
+		Whether stencil operations are performed against the stencil buffer. In order to perform writes or comparisons against the stencil buffer this value must be *true*. Default is *false*.
 		</p>
 
 		<h3>[property:Integer stencilWriteMask]</h3>

docs/api/zh/materials/Material.html

@@ -105,8 +105,7 @@
 
 <h3>[property:Boolean stencilWrite]</h3>
 <p>
-Whether rendering this material has any effect on the stencil buffer. Default is *false*.
-</p>
+Whether stencil operations are performed against the stencil buffer. In order to perform writes or comparisons against the stencil buffer this value must be *true*. Default is *false*.</p>
 
 <h3>[property:Integer stencilWriteMask]</h3>
 <p>