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Author Topic: Help with pattern making in Inkscape  (Read 309 times)

August 31, 2019, 09:14:06 AM
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bobdraw

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Hello again Lazur, Here is the image you need to see...Hope it's added to this post alright,
Bob  :-| Help with patterns in Inkscape.png
*Help with patterns in Inkscape.png
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Help with patterns in Inkscape.png
*Help with patterns in Inkscape.png
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August 31, 2019, 10:50:47 AM
Reply #1

Lazur

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Hi.

There is no way to make these automated by a few clicks in inkscape. There are g-code extensions that supposed to draw parallel lines.
Still, probably there is a conceptual roadblock on that.

You see in your examples the sharp concave corners are getting rounded at one point or another.
Also there are precision issues too.
The latter can be cured by adding a stroke attribute and converting the stroke to a path. It seems to be more precise and you can also set the corner types to be "spiky".

Still, that won't produce extrapolated paths, the corners will look somewhat off and can easily end up with odd node placement, double nodes etc.

My guess is the base of the issue is in using Bézier paths which compromise fast editing of random geometry to precise curves.
In a cad program, you can draw straight with polylines only built up by circular arcs and straight line segments, all of which can be extrapolated easily and draw parallel lines of any given shapes.

So although it is possible to achieve some results in inkscape and also with manual editing you can draw things look fine, but if your main focus is productivity and woodcutting of such objects as a regular activity, I suggest better look around at cad programs.
« Last Edit: September 01, 2019, 11:51:00 AM by Lazur »

September 01, 2019, 10:53:48 AM
Reply #2

bobdraw

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Hello Lazur, Thank you for your reply it was interesting to read, I think this Alex Fox Might be using a different program to do his patterns, I just thought I could do it in Inkscape, I will have think on what to do next, Thanking you,
Bob  :wink1:
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September 01, 2019, 04:48:46 PM
Reply #3

brynn

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Hhmm, now that I see your images, I'm not sure exactly what it is you want to do with Inkscape.  You should be able to send those paths to the cutter, assuming they are actual paths.  (We can't tell from the PNG images.)

There are other ways you might draw some of the images.  Not necessarily faster though, if that's what you want.

Can you explain exactly what you're after?
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September 01, 2019, 11:09:52 PM
Reply #4

Lazur

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Brynn:



https://www.youtube.com/channel/UC63fT9uKPvwRWGB9ZW4ESyA


This guy seems to work alot with a scroll saw.

Quite similar to this oldie.


In the video the example uses straight line segments which inkscape can handly pretty well -dynamic offsetting those.

But creating parallel shapes to a heart is a mess. Needs to split up the path at every concave nodes, extrapolate it manually, offsetting each of these paths by the same amount,
unconnecting the nodes that got connected automatically in the process,
and editing the rest together.
Or relying entirely on the offsets of the original posts and correcting every spot manually.
Either way, not so effective.


On a side note, that bunny may look a bit of an overkill even if done right with parallel lines -it won't resemble a 3D shape of the animal.
Rather it'd take to slice up a 3D model and generating cut lines. That, again is best suited by cad softwares and nurbs editing.
-Which itself is harder to be achieved since regular 3D polygon modelling won't do
nor the output is Bézier paths but B-splines.

September 02, 2019, 05:19:00 AM
Reply #5

brynn

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It sounds like you could do a lot of this with Inkscape.  Maybe not everything, or maybe not easily.  But some projects could be done with Inkscape.  Right?

There's someone in the new forum who is doing something similar to this, but not necessarily with the same shape.  Let's see if I can find that link....

Oh yeah, this one.  She calls it  multi-layered wood cutting https://inkscape.org/forums/cutplot/multi-layered-for-cutting/.  Look up the examples.

Before I saw Bob's examples, I thought he might be doing this.
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