Hi krass - so yes in a CAD program such a thing that you are describing is called "constraints" - you have to set up the constraints by assigning different types of them to individual features of your model, like you can tell it that a line should remain some certain fixed size, that another line should be tangent to a specific circle, and that there should be a 45 degree angle between 2 lines in another corner of the sketch. Then after those constraints are set up, you edit some piece of the drawing like move an endpoint or change the length on an unconstrained line, and then the rest of the model updates accordingly to enforce the constraints that you specified.

Pilou's examples above show some of that in practice, with other pieces of a sketch getting updated in response to an edit.

But typically in CAD programs functions like that are called "constraints". SolveSpace that I linked to above is one of the easier programs to mess with constraints because it's a very central focus of the program.


> And I'm trying to understand whether it is possible to realize (in principle) any
> improvement to solve this problem.

It is possible, but it will take a very significant amount of time and effort to do it, and the amount of interaction between the constraints and the overall platform makes it difficult for an external script to implement it. At this moment the best way to get that functionality will be to use a different CAD program in combination with MoI.

That type of functionality just has not been a focus area for MoI as of yet.

- Michael