Hello everyone. I have three ‘Closed Brep’ shapes (1, 2, and 3) that I want to combine into a single unit. Shape 2 is the middle shape, constructed from several hollow segments connected together. Shapes 1 and 3 are the caps for the middle shape. But as can be seen in the attached screenshot, the results can make what I want. When I combine 1 and 2, the result is one Brep, and when I combine 2 and 3, the result again is one Brep. But when all the Brep shapes are attached together, it does not work. Moreover, I want to calculate the volume of material and the moment of inertia of the combined shape.
This is related to your other topic. When you try to solid union all three breps, the result is an outside closed polysurface with a void inside of it.
Once again you can cheat by subtracting a tiny hole from either the top or bottom caps or you use a script like suggested in your previous topic about solid difference.
Thanks a lot Martin for your answer. Here, I do not want to subtract any shape. First, I created three Brep shapes, and then I want to connect them to each other. As you can see in the attached figure, there are three volumes that make the hollow unit. When I use the ‘Solid Union’ component for the bottom cap and the middle, it gives me one Brep. When I connect the top cap and the middle, it gives me one Brep again. But I can not make one Brep by joining together by ‘Solid Union’ component. I want to make all three volumes as one unit (One Brep), then obtain the mechanical properties (i.e., moment of inertia).
Let me know if I think in wrong way, please.
Look at your simplified example. The result is the same as if you subtract the inside from the outside. The result has one closed surface inside another closed surface
Thank you Martin for your time to answer my question. However, I did not get your point . If I have three ‘Closed Brep’ shapes, can I connect them to make one unit? You mean if one of the ‘Closed Brep’ has void space, it can not be connected to other shapes?
So it means Grasshopper can not recognize a ‘Closed Brep’ with void space. Either I should use a tiny hole to have a unit, or calculate the mechanical properties of the unit by myself.
… or use internal walls to create a valid closed BRep that encapsulates a void. You must have read about this in this thread, which was linked to you already once.
. If I have three ‘Closed Brep’ shapes, can I connect them to make one unit? You mean if one of the ‘Closed Brep’ has void space, it can not be connected to other shapes?
