I've made a extension to draw prefab concrete walls. Now I want to generate 2D views from each prefab element and generate a dxf file. Each element consists of a inner slab, isolation and outer slab. First I collect every face with a normal in the direction I want te make a view of. (e.g. front view: normal == Geom::Vector3d.new(0,-1,0) ). It works well for a front view but it doesn't work for a side view when there is a window in the wall because it draws every face with that normal including the window.
Is there a method to get all faces based on what you can see from a certain direction and from a certain group object?
And second, I want to generate a section over every window. Is there a method where I get all the intersecting lines between a group object and a plane?