Wire cut logic?

V8 Work In Progress
(8.0.23039.8305, 2023-02-08)

The logic of this command continually escapes me, especially when using multiple cutters.

A simple example will suffice:

1] Make a cube
2] Divide it visually into three roughly equal parts with two lines.
3] Call the wirecut command, select the two lines as the cutters, and the cube as the target.
4] The cube is cut into three parts, but there is always an added piece created, in that if you were to separate out the cut parts, their width is wider than the original cube by the width of either the left or right section.

What I’d expect (and want) is that the cut result is exactly the same as the split command would make, but with each piece being a closed polysurface.

The only way I can be sure of what it might do is just to use one cutting line at a time, in which case it works as I would expect.

This makes the command less useful than it might be, and presumably is intended to be, which is a shame.

I don’t know if the command is flawed, or if I am just too stupid to work out how it should be used; - I hope its not the 2nd, since I have been able to manage enough of the rest of the rhino toolset to transform my ideas into reality reasonably successfully for quite some time…

cheers
rabbit

4 Likes

Personally I think that’s the case, I would expect the results to be what you imagine.

Thanks for writing this up, @rabbit! This has been one of those “I just learned to live with it, but it really drives me crazy”-things! I’ve gotten used to connecting the cutters or calling the command twice, as using multiple cutters on a single geometry makes no sense in its current implementation.
-Jakob

1 Like

Just in case, here is a script that might help… Will split curves, surfaces and polysurfaces (not meshes) with either input curves or drawn lines. Note this is view-based, to if you are for example wanting to split vertically, you should have the top view active when choosing objects.

SplitObjsByView.py (8.0 KB)

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Well , this is simply brilliant!

This should be how the tool works natively…

thanks so much!

cheer
rabbit