Add switcher to polygon cut behaviour (auto cut - user choice)

[nstolyarov]

My actions before raising this issue

• Read/searched the docs
• Searched past issues

I am trying to edit a polygon by holding down the shift key and drawing a line inside the polygon. This is how I try to cut off a part of the polygon. When I click on the last point of the new line, I want to select which part to keep. There is such a function and it is described in the User Guide, but in reality it works once in five. In other cases, a smaller part is removed. In doing so, I do the same thing.

Expected Behaviour

At the end of the polygon editing, it becomes possible to choose which part to leave.

Current Behaviour

When you finish editing a polygon, the smaller part is removed almost always. In some cases it works correctly, but we haven't found such right conditions.

Possible Solution

Fix this problem.

Context

It is very important feature for our project.

Your Environment

• Git hash commit (git log -1): commit 7a2dcff (HEAD -> develop, origin/develop, origin/HEAD)
  Author: Anastasia Yasakova [email protected]
  Date: Tue Mar 9 10:41:33 2021 +0300
• Docker version docker version (e.g. Docker 17.0.05): 20.10.5
• Are you using Docker Swarm or Kubernetes? No
• Operating System and version (e.g. Linux, Windows, MacOS): GNU/Linux Ubuntu
  4.15.0-136-generic
  x86_64

[bsekachev]

Hi @nstolyarov

It is not a bug actually.
In the most of cases CVAT decides itself what part of polygon should be cut. In the past CVAT always left a choice for a user, but there were issues where users didn't like the behavior #1579 #1515.

Now it works in the following way:

Two criteria are computed to decide which part of a polygon should be cut during editing automatically. The first criteria is a number of cut points. The second criteria is a length of a cut curve. If both criteria recommend to cut the same part, algorithm works automatically, if not, a user asked to make a choice.

Related PR #1921

[nstolyarov]

Is it possible to add some toggle switch for choosing between smart and old version of editing?

[bsekachev]

@nstolyarov

Yes, it is possible.

[jahaniam]

Thanks for having this . Choosing automatically was also annoying to me sometimes. Toggle helps.