Mathematical Expressions can be used with this function to create regular patterns. The expression represents a function F(X,Y) that takes the input values X and Y and generates the output value (i.e. color). X and Y are just the horizontal and vertical coordinates of each pixel, with ranges from 0 to 1.

To find a mathematical expression for a specific pattern is not a trivial task. Artists can stay away from the Expression Parser and just use the Presets. However, sometimes it's easier just to write a single line of mathematical code than to draw the pattern by hand. Image 2 proves this with the xor(x,y) term.

The Tiling values expand the input range from (0..1,0..1) to (0..Horizonta,0..Vertical).