AutoCAD Answers – Hatching Spaces with Broken Boundaries
4 January 2018generalReading time 2MinPost view
Hatch in AutoCAD has historically been a challenge. Over the years it has improved tremendously but occasionally it can be problematical, especially when working with drawings from unknown origins.
In a recent training session for an architectural practice using AutoCAD for Mac, hatching was a constant issue because in the content of source drawings, areas that should have been wholly contained had gaps that were hard to find. This article enables us to discover how to bridge the gap.
Defining a Hatch Boundary
When creating a hatch the common method is to pick within an area that should be closed.
However, with busy drawings, when viewed at distance, gaps may not be visible, and zooming in doesn’t always help. AutoCAD will find these gaps, and when it does it will tell you where they are by circling the ends of lines that do not touch and giving a message confirming that a closed boundary cannot be determined.
Often, we can use these markers to go in and fix the issue manually; on other occasions, the gap may so small it is hard to find, or there are multiple gaps. When this happens, we could also tell AutoCAD to ignore gaps below a certain size by using a Gap Tolerance setting.
Gap Tolerance setting
We can find this in the hatch ribbon or in the properties palette / visor in AutoCAD for Mac.
The key here is to change the display settings from your personal ‘My’ properties setting to ‘All’ and this will reveal the Gap Tolerance setting. In here we can use a slider style adjuster or set a specific value, size, of gap to ignore.
In this example, I have set the value to 100 just for illustration purposes. Effective gap values will be different for different types of drawings and the nature of their content and could be just a few millimetres.
With the Gap Tolerance set, try the pick options again, and providing a suitable gap value has been set, AutoCAD will proceed with the hatch. However, it will still let you know that there is a gap and ask you how to proceed.
Go ahead and click on the Continue option.
There is an optional checkbox to set AutoCAD to Always perform my current choice that you can place a tick in or not.
AutoCAD will then commence to hatch the space, ignoring the gap.
Note, it does not correct or fill the gap but it does mean that we can carry on with the rest of our project.