Splitfeatures function

[Speed1987sS]

What is the bug or the crash?

Before update I use version 3.24
I can use "splitfeatures" function to split 3Dpolyline and 3Dpolygon with z value created with result.
After update to 3.30, I split 3Dpolyline and 3Dpolygon, i get "0" z value with vertex i splited.
Can anyone help to fix it?

Steps to reproduce the issue

No

Versions

After3.24

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response

[uclaros]

Steps to reproduce the issue

No

Unfortunately, this doesn't help much in reproducing your issue. It would be appreciated if you could add some step-by-step instructions!

[agiudiceandrea]

And please also add a sample layer.

[Speed1987sS]

Hi, Attach with 3D shapefiles and picture how I use the function (split with line / split features) step by step and the result with error in z value. thanks

…

On Thu, Mar 9, 2023 at 2:02 AM Andrea Giudiceandrea < ***@***.***> wrote: And please also add a sample layer. — Reply to this email directly, view it on GitHub <#52145 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6LESXUFL5IX74JU7CHYJRLW3DCSDANCNFSM6AAAAAAVTOQRLI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[Speed1987sS]

Sample

[agiudiceandrea]

@uclaros, I can confirm the issue on Windows using QGIS 3.28.4 and QGIS 3.30.0. The issue doesn't occur using QGIS 3.22.
The issue regards the "Split Features" tool in the Advanced Digitizing Toolbar and the Split with lines (native:splitwithlines) processing algorithm.

With the provided layers: the vertex added by the "Split Features" tool or the "Split with lines" algorithm between two consecutive vertices of the polygon perimeter, whose Z values are 20 an 22 respectively, has a Z value of 10.218 using QGIS 3.28 and 3.30, while it has a Z value of 20.436 using QGIS 3.22.

It seems the issue occurs splitting a polygon by a line and doesn't occur splitting a line by another line.

[troopa81]

With the provided layers: the vertex added by the "Split Features" tool or the "Split with lines" algorithm between two consecutive vertices of the polygon perimeter, whose Z values are 20 an 22 respectively, has a Z value of 10.218 using QGIS 3.28 and 3.30, while it has a Z value of 20.436 using QGIS 3.22.

the proposed PR fix the map tool part.

Regarding the algorithm native:splitwithlines, if the splitting line have Z values then the Z value at the intersection will be the mean value between the interpolated Z values of the splitting line and the polygon edge, and IMHO it's perfectly fine.