As you can see on the picture, I tried to cut a face with the knife tool while having the mirror modifier.
It seems to work well until you realize that on the mirrored cut, no vertices have been created, it is just showing a fake edge that cannot be selected. on the left part, I can select the two faces that result from the cut, while on the right part, I can only select the origin face.
Do you have an idea on what I am doing badly?
I have seen in another thread that the object has to be symetrical. Mine should be as I created a cylinder with 12 sides, and just extruded the top vertices before making the cut.
Thanks in advance for helping me (trying to learn blender is a really cumbursome journey ! )