For some models, the 'add' boolean operation creates a hole?

[increpare]

Affinity Designer Version : 1.7.3
OS: MacOS 10.15.1 (19B88)

Reprodcability: every time
Problem with new file also?: I've been able to reproduce it by pasting these shapes into a new file.

Select all, 

press what I assume is the "add" button (I use affinity designer in German)

notice that  my shape now has a giant hole in it

 

If I move the right shape slightly before doing this this behaviour no longer happens.  It seems to be related to the fact that both shapes have some vertices at the same positions? 

This came up trying to tidy up very messy vector stuff imported from Goodnotes on iPad. 

( Just started trying out affinity designer today - other than this I've been having lots of fun  )

test2.afdesign

Edited December 21, 2019 by increpare

[loukash]

Select one of the paths with the Node Tool, click the Reverse Curves button in the Context Toolbar, then select both paths, then Add.

But yeah, it's definitely not very obvious what's going on here.

 

Edited December 24, 2019 by loukash
Not a solution to this problem

[loukash]

3 minutes ago, loukash said:

Select one of the paths with the Node Tool, click the Reverse Curves button in the Context Toolbar, then select both paths, then Add.

Hm… wait.
It worked after I have done "something" else to the paths, but it doesn't work on your fresh file.

Needs more investigation…

[loukash]

Do they need to be this exact shape and position?
If you move one path only 0.1 px, then they add up as expected.

[loukash]

This intersection of paths is what's causing it:

It's likely neither a bug nor a feature; it's math.

[increpare]

Hi, thanks for the thoughts

>Do they need to be this exact shape and position?

No, but I was trying to import a bunch of data, and this happens a lot.  I just spent an hour or so manually going through all the changes and fixed things up manually.  Without a fix, I'll likely avoid this particular pipeline in future, though

When I zoom right in the geometry looks like bad auto-generated output but nothing too pathological.  There's also some freedom - I can move the point about a bit and the bug still happens.

>It's likely neither a bug nor a feature; it's math.

I don't I understand what you mean here - that it could be a tricky algorithm/precision problem that might be hard to fix?
 

[loukash]

22 minutes ago, increpare said:

I don't I understand what you mean here - that it could be a tricky algorithm/precision problem that might be hard to fix?

What I mean is that 1 + -2 = -1
That might be the case here.

[loukash]

Alright, there is some kind of a strange behavior in ADesigner.

This is what happens when "adding" a complex closed form with crossing path:

This is what Illustrator CS5 does with exactly the same two vector paths, using the "Vereinen" (= unite/merge/combine; no idea how it's called in the English version) Pathfinder function:

In theory both results should be the same, but only Illustrator does the logical thing and simply creates an outline of both forms.

[tobys-brain]

I seem to be having at least a very similar problem. I have had it occur both when trying to combine two shapes as well as trying to subtract one shape from another. In each case, all the nodes combine onto one layer, but instead of either creating one larger shape (in the “add” instance), one of the shapes is filled in, the other is empty, or (in the “subtract” instance), the smaller shape that should be the “hole” in the larger shape fills in and the larger shape is empty (again, all the nodes still there). I attempted to use the reverse function in the context tool bar, but got the same results.

One thing I did notice, though, after trying to add two shapes, based on some comments in this thread, I started inspecting to see if I had any overlapping nodes that would cause that “math” issue someone brought up. I found that every node on the filled in shape was doubled now. I could select each node one by one and move it around and there was still the original node in its original place. After moving the duplicate node around, the space between them would fill the way it should be. I could go around one by one deleting the duplicate nodes, but that’s not efficient. I’m not sure if this is a bug or if I’m screwing something up. Sometimes the functions work, sometimes this happens. The fact that every node on the infilled portion is doubled should be an indication of something, I just don’t know what. To me, a non-technically minded artist with a history of not getting along with the digital world (seriously, technology just seems to have something against me. My wife works in IT, and whenever I have a technical problem and get her into my studio to help me out, things just seem to work for her and she doesn’t see my problem), it would appear that somewhere in the process of trying to combine or subtract shapes, one of the shapes is being duplicated resulting in an empty fill.

No idea what to do about that.

Toby

[Patrick Connor]

Sorry you are having problems. We have been working again on Boolean operations. These changes are in a (currently internal only) Affinity Designer 1.8.0 build. Please can you retry these problem cases once the next Designer beta is posted in the beta area of the forums (and report your findings there). 

Thanks.