I need to cut a model into pieces. Thus, I tried using Knife and Knife Project Tools for that.
However, I noticed that the cut precision depends on the view scale. If I fit the entire model into the viewport window, some of the points of the cut line snap to the model’s existing near points.
If I zoom in, the cut gets more precise but still not ideal.
So, the question is: Is there a way to get precise cutting in Blender?
Note: Other options than Knife Tools are OK too.
Im not entirely sure if it would be a solution (im not oftenly use this command), but you can try a Mesh Knife Intersection.
Its on the Face > Intersect (Knife).
For make it works, you need to join you main mesh and the mesh which will be used as a cutter, then select all polys in the main mesh and use those command.
What you are asking for is, frankly, highly counter-productive, and is bad practice in the world of 3d.
You want to cut something in such a way where two vertices are placed .0001 distance apart?
The problem is not Blender, but your work flow, expectations and understanding of how to build topology.
No. There is about 2 mm distance between neighbor vertices. But anyway, I noticed that the precision of the result depends on the viewport scale.
Thank you for replying! Unfortunately, I doesn’t work in my case 
For this kind of cutting usually a boolean operation is used… you may construct you cutting object by snapping to any vertex of you to-be-cutted object or copieing some vertices to make this up from… of course ther could be some vertices made up you want to clean up afterwards…
Thank you for replying! It looks like cleaning will be required for any method that may be used.
Sorry but based on your own screen grabs you are wrong. And your workflow and expectations are wrong.
IceCaveMan, could you recommend me a proper workflow?
P.S.: I have experience in Engineering CAD modelling only, thus, I think it that way
There is nothing like a wrong workflow… maybe not so good suited… and of course there is mostly always a smarter way to do things… and just telling they are wrong doesn’t really help…
Okidoki, thank you for the nice solution! Didn’t use Blender for some time (when the Boolean Modifier was not so precise) and forgot to check that option.
Blender is getting better every day… 
… happy blending…
