AutoCAD Tip – Unable to Trim Hatch Element?

By Dennis Collin

Hatch fill elements are very useful objects and are used to show solid materials in sectional views or possibly area functions in plan. Since AutoCAD 2005 users have been able to Trim Hatch pattern entities to represent islands in plan, section, and elevation drawings. This useful function hopefully dissuades users from using the Explode command! A big ‘NO, NO’ in any office!

Although existing Hatch elements do not update when new boundaries are added, AutoCAD can be instructed to update the hatch extents to new boundaries by manual modify commands. In most cases users can introduce islands by using the trim function on a cutting boundary and click on the hatch element to remove. Alternatively, the Hatch edit command can be employed where new boundaries can be selected to control the hatch.

Occasionally, though the Hatch element does not respond as expected to Trim command operations or the addition of new hatch boundaries selected within Hatchedit.

The reason for this is a few years ago, the default hatch boundary behaviour was changed. Originally the boundary was set to Island detection, however now it is set to Outer Island only. Which means in certain instances of complex hatching AutoCAD seems to fail to respond!

This is easily addressed however, by clicking on the hatch and changing the island detection mode from Outer (or maybe Ignore) to ‘Normal’. This will ensure the hatch responds and behaves as expected. If the trim or edit command has already been attempted the hatch extents should display as desired.

Hatch elements are complex elements which often confound even experienced AutoCAD users, if you want to learn more on AutoCAD from the Basics to more Advanced topics consider attending a training course. We run standard scheduled courses, or if your needs are specific can deliver tailor made workshops and help make your workflow run smoother. Call one of the Cadline Team now or have a live chat on https://training.cadline.co.uk/