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TheGrudge

Merging divided shapes creates weird shapes

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Hi,

coming from Inkscape and knowing Adobe Illustrator I never seen the following problem, but it really gets annyoing:

I have strokes that overlap. Normally I would delete the overlap with an eraser tool, but AD doesn't have such a tool, so I select all the strokes and divide them.
Now I have little pieces, that can be deleted. After the divide operation, you can see little gaps (I know it has to do something with the render engine). These gaps seem to cause a problem when adding all the remaining shapes together.

The resulting shape has paths that "flow" into each other. The shape looks like a normal shape, but when you try to add a border around the newly created shape, you get weird results. I have added a testfile to this post so you can see the problem.

In Inkscape this would be one continuous shape, but in AD the gap seem to be an issue when adding the shapes back together. These gaps seem to be more than just a render issue.

I really like AD and I already bought the license, but this becomes more and more an issue and I am not able to work the way I want to. 

I could use the eraser in the pixel persona, but this only creates a mask which is not apply-able, so nothing is actually deleted. I could draw shapes around the overlapping parts and use "subtract", but this is very time consuming. 

Is there a workaround of some kind?  

 

test_add.afdesign

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Ok I just tried the following:

  • I added everything to one shape
  • I duplicated the shape
  • added a 0.3pt stroke
  • expanded the stroke
  • merged those objects again

This seems to work, it is not the best workflow, but it seems to work for now (as long as it is no problem having a bigger shape afterwards).

I still hope this issue will be fixed or that there is another solution to this

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I am not sure what you want to do but if it is to create a shape that looks like your "expanded strokes add" layer, but without the overlaps & gaps, something like this:
227948353_strokedcurve.jpg.d70ae01cfb1d654d5de9e8fdeead5784.jpg

there is an easy way to do it

  1. Boolean add the two curves in your "expanded strokes" layer to get a "(Curves)" layer
  2. Add a stroke to this "(Curves)" layer
  3. (Optionally) tick the "Draw behind fill" checkbox in the Stroke panel to retain the thickness of the fill

The attached test_add 2.afdesign includes each step as a separate layer so you can see the progression from step to step.


Affinity Photo 1.6.7 & Affinity Designer 1.6.1; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
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No, I want to delete the overlapping parts like in my example file. 
The idea is to be able to quickly remove overlaps, and since there is no eraser tool I wanted to realize this with the divide operation (my second layer 'expanded strokes divide').
I then remove the parts I do not want anymore (my third layer is 'expanded strokes cleanup') and want to merge those shapes with add (my fourth layer 'expanded strokes add').
Now, however, weird curves are created by the minimal gaps after the divide operation.

You can see this kind of workflow in the video tutorials by Jason Secrest, for example here:

https://youtu.be/yo_cTJfiwm8?t=516

The only way I was able to fix this is by creating a tiny border after the add operation (see my second post), expand the stroke and add this back to the curve. This will remove the gaps and "floating" curve handles in the shapes body and render a clean curve again. It will be slightly larger than the original curve, but in this case I'm ok with that.

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test_add FD Styli.afdesign Saved with history so you can jog back and forth in the history panel. 


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Hi, TheGrudge,

I don't use Inkscape much, and haven't used Illustrator for years. So I can't comment on how they operate in this situation.

From what I can tell, the  divide operation creates new shapes, and tries to fit the paths to close to what they were based on the original curves. The problem you are seeing is when the shapes are added back together. The divide routine created outlines that did not perfectly match the pre-existing arcs. When they are added together, the miniscule differences are not ignored, and very tiny curve objects are created. sometimes, they are just 2 nodes a 1000th pt apart. It can be a major pain deleting those.

So if you just add the expanded strokes together, it is somewhat less irksome to delete the over lapping parts nodes. A few dozen, instead of hundreds+. The time it takes to tweak the outline still does not exceed whittling away the excess objects.

I have no idea what is going on internally, but it might be an improvement if the add routine had a minimum distance parameter that allowed objects less than , say, 100th a pt to be ignored.


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test add 3.afdesign, also saved with history so you can jog back and forth in the history panel.

To avoid creating all those troublesome extra curves, no divide operation was used. Not as quick & simple as with a vector eraser, but by doing it this way there is no need to be careful about erasing too much or too little.


Affinity Photo 1.6.7 & Affinity Designer 1.6.1; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.6.11.85 & Affinity Designer 1.6..4.45 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.1.1

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17 hours ago, R C-R said:

test add 3.afdesign, also saved with history so you can jog back and forth in the history panel.

To avoid creating all those troublesome extra curves, no divide operation was used. Not as quick & simple as with a vector eraser, but by doing it this way there is no need to be careful about erasing too much or too little.

Yes this is like creating a shape and subtracting it. it works fine, but when you have a lot of "overlaps", it is a little bit time consuming. I guess I'll stick with my "border" solution for now, maybe the issue will be fixed in AD sometime.

 

Thank you all for your answers and suggestions! :-) 

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19 hours ago, TheGrudge said:

The idea is to be able to quickly remove overlaps, and since there is no eraser tool ...

No there sadly is no real vector one, there is only one eraser tool in the pixel persona which then masks the removed parts with a sizable pixel brush.


☛ Affinity Designer 1.6.1 ◆ Affinity Photo 1.6.7 ◆ OSX El Capitan

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this might work:

select both expended strokes duplicate and select the 4 shapes and do a boolean add


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Yes the boolean issues are annoying :|.

I'll throw in another workaround:
(it doesn't have to be one continuous shape. Could be multiple shapes.... still just one subtract click)

107115644_Booleanworkaround.gif.c34cc50f85154ca4844c608b5cb10d21.gif

 

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That's also a good idea. Nevertheless, I wish they'd fix this gap problem, because this also happens when shapes are positioned next to each other by the snap tool. You can see a small gap there as well, even when rendering as PNG. This is also annoying since you have to fix this manually by putting shapes behind the gap oder adding a border to the shape with the same color as the fill.

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