Draw irregular shapes with parallel sides

Post questions on how to use or achieve an effect in Inkscape.
Thor
Posts: 3
Joined: Sat Jul 13, 2019 9:00 pm

Draw irregular shapes with parallel sides

Postby Thor » Sat Jul 13, 2019 9:12 pm

Hello Team,

Please look the attached image. I wants to draw parallel shape with same distance from each side.
Distance may vary as per needs. Try a lot with suggested option in forum but not succeeded.

Can any one one guide me how to do this?


Thanks,
Thor
Attachments
issue.svg
(6.35 KiB) Downloaded 37 times

User avatar
druban
Posts: 1871
Joined: Fri Nov 20, 2009 10:48 pm

Re: Draw irregular shapes with parallel sides

Postby druban » Sun Jul 14, 2019 6:59 am

This idea always seems like it should be possible but it is generally impossible to draw a curve that is always exactly the same distance from another curve.
However your statement, "Distance may vary as per needs" has confused me, because it's not a parallel shape then?

If you mean that you just want to trace this image, that's a different thing. This image IMO is too pixelated to trace well except that it's so coarse that you can simplify a lot without losing anything since there is no detail to be obscured by the pixelation, and the results are not terrible by any means... Deleting the cross is not that difficult but takes that much more time.
Others have techniques that apparently require low resolution images for tracing, I don't know of those techniques.

The upside of having such a low resolution image is that it takes only minutes to trace by hand.
From there it's easy to create a "parallel" shape. For this I used the thick stroke method.

image3737.png
image3737.png (53.17 KiB) Viewed 643 times
Attachments
issuetraced.svg
(66.67 KiB) Downloaded 37 times
Your mind is what you think it is.

Thor
Posts: 3
Joined: Sat Jul 13, 2019 9:00 pm

Re: Draw irregular shapes with parallel sides

Postby Thor » Sun Jul 14, 2019 6:00 pm

Thanks for quick reply.
by the way, it is plt file not a image file. For easy reference attached as image file.
The distance vary mean I want to create parallel shape with different distances 2,4,6,8,10...
So can you help me to create image with parallel different distance?

Regards

tylerdurden
Posts: 2330
Joined: Sun Apr 14, 2013 12:04 pm
Location: Michigan, USA

Re: Draw irregular shapes with parallel sides

Postby tylerdurden » Mon Jul 15, 2019 12:14 am

I would use duplicate and outset operations.

If you have a preferred increment, you can set that in the preferences dialog.

Here I'm making a few, and I can copy/paste the ones I want, or delete the ones I don't.

Image
Have a nice day.

I'm using Inkscape 0.92.2 (5c3e80d, 2017-08-06), 64 bit win8.1

The Inkscape manual has lots of helpful info! http://tavmjong.free.fr/INKSCAPE/MANUAL/html/

Thor
Posts: 3
Joined: Sat Jul 13, 2019 9:00 pm

Re: Draw irregular shapes with parallel sides

Postby Thor » Mon Jul 15, 2019 2:38 pm

Hello Team,

Please look attached image marked as red rectangle. The image curve getting change after "outlet".
Is there any way to do it without this curve change?

Thanks,
Attachments
error.png
error.png (15.86 KiB) Viewed 596 times

User avatar
druban
Posts: 1871
Joined: Fri Nov 20, 2009 10:48 pm

Re: Draw irregular shapes with parallel sides

Postby druban » Mon Jul 15, 2019 3:23 pm

I said, "This idea always seems like it should be possible but it is generally impossible to draw a curve that is always exactly the same distance from another curve."
Meaning exactly this, when you have a curve that has any concavity and convexity (loosely put, some part of it cannot be represented by a quadratic, or that any line tangent to the curve will also intersect the curve) you can't trace a parallel without it intersecting itself. To avoid that, which would be graphically undesirable, Inkscape cuts off the 'loops' created and smoothes the result. No amount of skill can avoid simple mathematical reality, sorry!
Your mind is what you think it is.

Lazur
Posts: 4709
Joined: Tue Jun 14, 2016 10:38 am

Re: Draw irregular shapes with parallel sides

Postby Lazur » Mon Jul 15, 2019 4:54 pm

Hi.

Apart from the fact that no two curved Bézier path segments can be parallel exactly -mathematically speaking- there were some hopes planted before on better joins. Have no idea what happened to that feature.

extrapolated joins

Polygon
Posts: 379
Joined: Thu Dec 19, 2013 3:27 am

Re: Draw irregular shapes with parallel sides

Postby Polygon » Mon Jul 15, 2019 9:27 pm

I found the most precise way is to make a bigger outline, convert to path&separate:
BirdOfPrey.jpg
BirdOfPrey.jpg (52.18 KiB) Viewed 564 times

Cheers

Moini
Posts: 3316
Joined: Mon Oct 05, 2015 10:44 am

Re: Draw irregular shapes with parallel sides

Postby Moini » Mon Jul 15, 2019 9:39 pm

Polygon, you mean: apply different stroke widths and do stroke to path?
Something doesn't work? - Keeping an eye on the status bar can save you a lot of time!

Inkscape FAQ - Learning Resources - Website with tutorials (German and English)

Polygon
Posts: 379
Joined: Thu Dec 19, 2013 3:27 am

Re: Draw irregular shapes with parallel sides

Postby Polygon » Mon Jul 15, 2019 10:46 pm

Moini wrote:Polygon, you mean: apply different stroke widths and do stroke to path?

Exactly - I have now changed Inkscape´s UI language to English - hopefully it will prevent me from using the wrong terms in the future. :oops:

Cheers

Moini
Posts: 3316
Joined: Mon Oct 05, 2015 10:44 am

Re: Draw irregular shapes with parallel sides

Postby Moini » Tue Jul 16, 2019 7:33 am

I forgot the 'break apart' part ...
Yep, I use Inkscape in German for production, and in English for support (unless it's the German forum, of course ;-) ), too.
Something doesn't work? - Keeping an eye on the status bar can save you a lot of time!

Inkscape FAQ - Learning Resources - Website with tutorials (German and English)


Return to “Help with using Inkscape”

Who is online

Users browsing this forum: No registered users and 6 guests