Hatch as hidden lines?

[jerome]

Another hatch question please...

I need to hatch an object that is hidden but it seems I can only use solid lines for hatches - is this correct? (eg. hatch pattern ANS131)

[john.vellek]

Hi @jerome,

I see that you are visiting as a new member to the AutoCAD forum. Welcome to the Autodesk Community!

You can certainly hatch boundaries that are not continuous lines.  What version of AutoCAD are you using? When I do a hatch it works fine but it might be that I have LTGAPSELECTION turned on (available from 2017) although it seems to work fine in 2016 too.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Kent1Cooper · Accepted solution]

Try:

A)  The DASH pattern.

B)  Assigning the Hidden [or whatever] linetype to an ANSI31 [or other] Hatch Pattern in the Properties palette or with CHPROP.

C)  Hatching with ANSI31 [or other] on a Layer that has a Hidden [or whatever] linetype assigned.

The advantage of A), if that patterns looks right to you, is that with B) or C), you get irregularities in alignment of the dashes with irregular boundary shapes:

A pattern similar to DASH with different ratio between dash and gap sizes, and/or with the dashes aligned in both directions rather than staggered halfway from one line to the next, could easily be defined.

[jerome]

Thanks for your reply, John, and for your welcome.  I didn't explain myself well I think - I understand that a dashed boundary won't cause issues but I was hoping there was some way that the hatch pattern itself could be changed to a dashed line

[jerome]

Thanks, Kent.

having [ANS131] on a hidden layer doesn't seem to work

 

  (sorry for the huge .jpg)

I didn't think to use 'dash' at 45deg and this will work well for my purposes so, thanks again for another solution.

[Kent1Cooper]

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@Anonymous wrote:

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having [ANS131] on a hidden layer doesn't seem to work

....

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That may be a version-dependent difference.

[john.vellek]

Hi @jerome,

I can confirm your findings with ANSI131 in core AutoCAD.  @Kent1Cooper, which flavor of AutoCAD did you test in? I am curious why the hatch render is different in that vertical. 

I like the suggestion of using a dash pattern which achieves the desired results.

[jerome]

if it helps (either of you) I'm using full AutoCAD 2017

[Kent1Cooper]

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@john.vellek wrote:

....  @Kent1Cooper, which flavor of AutoCAD did you test in? I am curious why the hatch render is different in that vertical.  ....

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No vertical -- vanilla AutoCAD 2016.  EDIT:  But since I'm currently at a different location also with vanilla Acad2016, I tried it again, and it didn't  work.  I don't know what could be different about the setups that would explain that.  Could the difference between Windows 7 [in which it worked] and Windows 10 [didn't] possibly be the reason?

[jerome]

I couldn't get this to work on my laptop, running windows 7 & ACAD2016

[Kent1Cooper · Accepted solution]

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@Kent1Cooper wrote:
....  I don't know what could be different about the setups that would explain that.  ....

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FOUND IT!  There's a System Variable, called [obviously enough] HPLINETYPE, which if set to 1 or ON, will use non-continuous linetypes in Hatch Patterns.  That's described as "legacy behavior" in Help, so I assume it just works that way all the time in older versions, but I don't know in which version the option was introduced.

In a Hatch Pattern that is not  of continuous lines, the linetype appears to be applied onto each pen-down segment within the Hatch, separately, provided the scale of the Hatch relates to the linetype scale in such a way as to allow that.

Also, it works even with text- or shape-embedded non-continuous linetypes, not just those made of dashes/dots/gaps.

[jerome]

Excellent! Thanks very much Kent!

[Anonymous]

Thank you very much of ur solution. I had been searching for it quite some time. 😊👍