To cookie/cut an L system, I attempted 2 ways: 1. use metaballs as a boundary zone to limit its growth but there are sometimes protruding lines from the L system; 2. Polywire the L system then cookie it with a volume but the cut section always have more than 3 points as polywire makes L system into a 3D polygon. Both methods do not do clean cuts.

Is there any other way to have a clean cut wherever I want in the L system?