Changing the fill rule

Using fills

Changing the fill rule

Normally you'll just create simple outlines, and fill them. However, there'll be times when you draw paths that loop over themselves, and so form regions within the overall outline. Two different rules get used to determine whether or not to fill such internal regions. You set which one to use in the Fill Properties window:

Select the fill; see Selecting fills above.

Ensure the Properties window is displayed; if it is not, choose View > Properties.

Use the Rule buttons to choose which rule you wish to use.

It's not always easy to work out which rule you require; perhaps the best thing to do is to try both rules, and see if one gives the required shape in the Drawing Window. These are how the rules work:

With Odd-Even fills, the region is filled only if a line going outwards from the region crosses the path an odd number of times, before the line reaches the area outside the shape.

With Zero-winding fills, the region is filled unless a line going outwards from the region crosses the same number of paths going from right to left as those going from left to right, before the line reaches the area outside the shape.

If you can't get the shape you require, remember that you can use multiple paths in a Vector node, and make a complex shape from a number of smaller shapes. For example, you might draw a black circle, and then draw a white circle inside it, so you have a doughnut-shaped grayscale matte.

Using fills

Changing the fill rule