topic How to create a custom hatch with an ARC or circle? in AutoCAD Forum

How to create a custom hatch with an ARC or circle?

mdallinga — Fri, 04 Jun 2021 12:35:31 GMT

Hello guys,

I need some advice on creating a custom hatch pattern consisting on an ARC/circle. Now I know one way of making custom hatch through making a notepad file and saving as .pat file and then importing in Autocad. But all the examples I saw online show pattern for only lines and not ARC/circles. I understand that a hatch pattern can contain only straight segments. But there must be a way to do it. I'm aware of the command SUPERHATCH, but that's not the one i'm looking for.

I have attached an image below of the ARC and what I want the hatch to be like. On the right I have drawn the ARC only using polylines, so that should work in a notepad file (in the attachment the .dwg). I just don't know how to write the code when I use so many polylines.

I hope someone can/will help me.

Cheers,

Maarten

Re: How to create a custom hatch with an ARC or circle?

Alfred.NESWADBA — Fri, 04 Jun 2021 12:48:39 GMT

Hi,

>> I understand that a hatch pattern can contain only

>> straight segments.

Sorry, you have found your answer, a hatch pattern can only contain lines and not arcs.

The best you can do is to convert your arc into a number of segmented lines and use it this way.

You might take a look to some free stuff like >>>this<<< (and I'm sure you'll find more samples).

- alfred -

Re: How to create a custom hatch with an ARC or circle?

pendean — Fri, 04 Jun 2021 12:55:31 GMT

While you wait... Explore this attached for how arcs are created with short straight segments.

HTH

Re: How to create a custom hatch with an ARC or circle?

Kent1Cooper — Fri, 04 Jun 2021 17:25:07 GMT

It's done as you surmise, as in portions of the middle and right pattern images >here<, or >this one<. If those are too kinky for you, it can be done with more segments, to look closer to real curvature, such as in the right side of >this<., or my CirclesTriGrid patterns >here<, which do this kind of thing:

Those are actually 24-sided polygons. It's certainly possible to take elements of how they are defined and make a pattern like your image.

EDIT:

Here's what your pattern would look like if made with portions of what would be 24-gons if they were complete "circles":

Is that "curvy" enough for you? It's only 9 segments per "arc," as compared to 21 in your drawing file.

Re: How to create a custom hatch with an ARC or circle?

hugha — Sat, 05 Jun 2021 06:08:58 GMT

Try the pattern contained in the attached file.

the pattern was created directly from a WBLOCK'd DXF of the seminal arc, arranged on a skewed mesh..

hth,

Hugh Adamson