Added smoothStep

src/gl_engine/MathHelpers.java

@@ -72,6 +72,10 @@ public class MathHelpers
 		return Double.NaN;
 	}
 	
+	public static double smoothStep(double a) {
+		return a * a * (3 + 2 * a);
+	}
+	
 	public static double sqrt(double a) {
 		return Math.sqrt(a);
 	}