efficiently slicing an arch bridge model into multiple non-planar blocks

Question

I have a set of different meshes representing different arch bridge geometry.

I want to slice it into 'blocks' that can be 3d printed and stacked to make the arches. An example of the slicing planes is shown in the image below. One way seems to be duplicate the planes. Join alternate pairs of them, edit them into triangular manifold wedge blocks, duplicate the arch 6 times, and run boolean intersections between the wedge blocks and the archs to get each seperate block.

Is there a more effective way? I'm keen to learn geometry nodes or sverchok, but also keen to just get better at blender.

Answer 1

You are right. What you have suggested is the way to do it properly. However, you can "cheat", if you are not going for maximum precision. Since you want to 3D Print your model, it's going to be fine.

So, first join all your "Tool Planes" into one single Cutter Object with CTRL+J and give it a Solidify Modifier with a super small Thickness.

Then give your bridge a Boolean Modifier (Difference) and use your Cutter as the Tool Object. Finally, apply the Boolean, delete (or hide) the Cutter and go into the Edit Mode of your Bridge and hit P to separate the Mesh by its loose parts.

Now you can select, export and print these single parts:

NOTE: For demonstration purposes, I made the gaps (Solidify Thickness) between the bridge blocks rather wide - you can go really small here.