Hello,

I have been having some problems cutting combined paths in Inkscape 0.48.3.1 r9886 on Xubuntu Linux. ( This is the latest version via automatic update at the moment )
When I cut the path,randomly some of the original objects which were combined are not cut. I have tried to repeat the error in Windows using various recent versions of Inkscape but it does seem to be affected.

There is an example below:

- Draw square
- Copy and paste in place several times
- rotate each copy to make a fancy effect
- select all and combine paths ( Ctrl + K)
- Draw a line and move to the top ( press home )
- select all and cut path ( Ctrl + Alt + / )




Anyone know why this happens ?

Thanks

Welcome to InkscapeForum!

Well first I should say that no matter which operating system you're using, that may not be the best way to accomplish what you want. Although what you want isn't entirely clear to me. You basically want half of the "fancy" compound path to disappear? Or you just want it in 2 pieces? It seems that when Cut Path is applied, one part of the compound path is duplicated. If you look closely, you may find the 2 parts of a square right on top of that apparently uncut square. At least that's what happens when I try it. Note that I'm trying this on Win7Home 64-bit, Inkscape 0.48.4. Although as I said, operating system is probably irrelevant in this case.

This would probably be the better way to approach that (assuming I understand correctly):



However, when I do that, I get an extra square that wasn't there before:



So you can see I've colored the square that didn't get cut red, and I pulled it out from the original result. The 2 blue pieces were right on top of the red one. And when they were black, you couldn't really see them. I can't explain why that happens. But path operations generally tend to get confused when you try to use compound paths. They really work best when using 2 simple, closed paths. Please see the manual for details.

I suspect you're wanting something like a razor tool, which has been a much requested new feature. But at the moment, Inkscape just can't do what you want -- i.e. cut along a drawn line. There may be other ways to get rid of half that "fancy" object, but cutting it in half cleanly....well all I can think of at the moment, would be node editing. But maybe some other clever Inkscaper could come up with something better.

Pilosopong Tasyo wrote:Inkscape already has a dedicated eraser tool, of course, although using path operations to simulated it is also possible

I believe that the eraser tool is entirely boolean under the hood. If you observe it in operation you will see the path it draws and the resulting boolean calculation. Of course on your superfast 21 core machine it probably flashes by too fast to see anything at all!

Here are your choices:



1. Doing the same you did, produces a closed path. I have no idea how you achieved yours.
As the cutting path doesn't have any width, the boolean action merges the parts together as described in another thread.

2. Still making a same cut, this time, with a closed path on top. It merges things alltogether, at least one part is deleted.

Cutting paths work best with paths that have a fill only and no outlines.
On the image you posted, there are still problems with the "right cut" part: the path's ends doesn't have one solid edge.
That is because the boolean wasn't applied to the outline of the curve.

3. Solution1: masking the wanted part with an object on top.

4. Solution2: clipping the wanted part with an object on top.
Notice that when masking, the bounding box will be covering the union of the mask object and the masked object, while with clipping it will cover exactly the clipping object.

5. Solution3: conert outline to path on both objects, then apply boolean.

To show the methods I didn't used one "line" on top, because the result is better shown this way.
At solution1 and 2 you would have to do the same thing with the left and the right parts, and, they would be aligned next to eachother -if that's what you were after.

At solution 3 I used similar object to the masking, because I don't see the point of making a gap between the two cutted parts, but it is possible to make.