Math: Added nextPowerOfTwo method.

src/math/Math.js

@@ -150,6 +150,20 @@ THREE.Math = {
 
 		return ( value & ( value - 1 ) ) === 0 && value !== 0;
 
+	},
+
+	nextPowerOfTwo: function ( value ) {
+
+		value --;
+		value |= value >> 1;
+		value |= value >> 2;
+		value |= value >> 4;
+		value |= value >> 8;
+		value |= value >> 16;
+		value ++;
+
+		return value;
+
 	}
 
 };