Symmetric scissor effect issue

The size range in the scissor slice cut symmetric effect is specified in mm, but the number appears to be the number of slices. If I pick 20mm, regardless of the range in my data set, it will do +/- 10 slices from where I draw my scissor region.

This is in a recent nightly build.

I confirm that it is in slices. Could you please enter a bug report at If you could submit a pull request with the fix then it would be even better.

I’ll try fixing it - might have a couple of questions along the way. I know C/C++ and a little python, but I’m very new at the innards of slicer.


I had a look and the issue and it was simple enough so I went ahead and fixed it. It’ll be available in the nightly release on Saturday.

Thank you for reporting the issue and offering your help to fix it!

Wow, thank you!

I’d gotten as far as figuring out how much I didn’t know (which was extensive, to say the least), so reading through your fix will be a very useful tutorial for me.

Thanks again!