show only if mask is true

examples/js/nodes/materials/nodes/PhongNode.js

@@ -168,7 +168,7 @@ PhongNode.prototype.build = function ( builder ) {
 
 			output.push(
 				mask.code,
-				'if ( ' + mask.result + ' ) discard;'
+				'if ( ! ' + mask.result + ' ) discard;'
 			);
 
 		}

examples/js/nodes/materials/nodes/SpriteNode.js

@@ -140,7 +140,7 @@ SpriteNode.prototype.build = function ( builder ) {
 
 			output.push(
 				mask.code,
-				'if ( ' + mask.result + ' ) discard;'
+				'if ( ! ' + mask.result + ' ) discard;'
 			);
 
 		}

examples/js/nodes/materials/nodes/StandardNode.js

@@ -205,7 +205,7 @@ StandardNode.prototype.build = function ( builder ) {
 
 			output.push(
 				mask.code,
-				'if ( ' + mask.result + ' ) discard;'
+				'if ( ! ' + mask.result + ' ) discard;'
 			);
 
 		}

examples/webgl_materials_nodes.html

@@ -1359,7 +1359,7 @@
 						mtl.mask = new THREE.CondNode(
 							texArea, // a: value
 							threshold, // b: value
-							THREE.CondNode.LESS // condition
+							THREE.CondNode.GREATER // condition
 						);
 
 						// GUI