update BufferGeometry.toCreasedNormals() documentation

Author: kpvhn

docs/examples/en/utils/BufferGeometryUtils.html

@@ -126,7 +126,17 @@ <h3>[method:BufferGeometry toCreasedNormals]( [param:BufferGeometry geometry], [
 		geometry -- The input geometry. <br />
 		creaseAngle -- The crease angle. <br /><br />
 
-		Creates a new, non-indexed geometry with smooth normals everywhere except faces that meet at an angle greater than the crease angle.
+		Modifies the supplied geometry if it is non-indexed, otherwise creates a new,
+		non-indexed geometry.<br /><br />
+
+		Returns the geometry with smooth normals everywhere except faces
+		that meet at an angle greater than the crease angle.<br /><br />
+
+		Backwards compatible with code that uses this method to operate on the original geometry.<br /><br />
+
+		[page:BufferGeometry.toNonIndexed]() warns if the geometry is non-indexed and
+		returns <code>this</code>, i.e. the same geometry on which it was called:<br /><br />
+		<code>BufferGeometry is already non-indexed.</code>
 		</p>
 
 		<h3>[method:BufferGeometry toTrianglesDrawMode]( [param:BufferGeometry geometry], [param:TrianglesDrawMode drawMode] )</h3>

docs/examples/zh/utils/BufferGeometryUtils.html

@@ -125,7 +125,17 @@ <h3>[method:BufferGeometry toCreasedNormals]( [param:BufferGeometry geometry], [
 			creaseAngle -- The crease angle.
 		</p>
 		<p>
-		Creates a new, non-indexed geometry with smooth normals everywhere except faces that meet at an angle greater than the crease angle.
+			Modifies the supplied geometry if it is non-indexed, otherwise creates a new,
+			non-indexed geometry.<br /><br />
+
+			Returns the geometry with smooth normals everywhere except faces
+			that meet at an angle greater than the crease angle.<br /><br />
+
+			Backwards compatible with code that uses this method to operate on the original geometry.<br /><br />
+
+			[page:BufferGeometry.toNonIndexed]() warns if the geometry is non-indexed and
+			returns <code>this</code>, i.e. the same geometry on which it was called:<br /><br />
+			<code>BufferGeometry is already non-indexed.</code>
 		</p>
 
 		<h3>[method:BufferGeometry toTrianglesDrawMode]( [param:BufferGeometry geometry], [param:TrianglesDrawMode drawMode] )</h3>