larchitect This topic is far more complex than it may look. If we talk about trimming on a flat surface oriented in a regular XYZ world and we should consider only flat projection assumptions that may seem straightforward though still there's a "Custom Axis" to handle. However, when we'll start considering projections based only on a three-dimensional shape sampling, things are getting really complicated, and not so obvious. Here we're talking about something like an arbitrarily shaped clipping plane perpendicular to boundaries that goes through boundaries in all three dimensions 🙃