Author Topic: How to create a specific sized and shaped hole at a specific location?  (Read 894 times)


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The title might be confusing so I'll try to explain what I want to do. I created a 3D model of the liver, its artery and its vein (portal vein). They are 3 separate objects. I am going to print the artery and the vein as a single object (I have joined them with a tube like structure so they can preserve their spatial relationship). Then I am going to cut the liver model using plane cut in 4 pieces and  print these as hollow models (%0 infill). These pieces will serve as molds for transparent silicone or ballistic gel, so I'll end up with a transparent liver model. However, just before pouring the silicone or gel, I want to insert the artery and the vein inside the molds, so that they will be included in the transparent model. The problem here is to be able to create the holes where the artery and vein penetrate the liver. I can do a boolean substraction from the liver model and it creates these holes where I want them but it also creates a very complex tubular system inside the model, as the arteries and veins inside the liver are also substracted. Is there a way to delete these tubular structures, so that I only have the liver model with just the holes on the surface? Is there a better way to create these holes instead of using boolean operations?



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Think with BooleanDifference you're on the right track.
Performing BooleanDifference (A-B) creates an object where resulting surfaces' faces are grouped based on the source objects.
Do  BooleanDifference A (liver object) - B (artery object) = A1. Now do BooleanDfference A1 - C (vein object) = A2.
Now with A2 active go to SELECT and select some part of the former A object. Hit G to expand the selection to the group coming from the A surface.
Hit I to invert the selection and hit X to discard all surfaces coming from the B or C object....
This results in a single shell with open boundaries.

On your A object SELECTall (Ctrl+A)
On this selection run Edit/Offset. Set a positive offset (the thickness you want to print the mold). This flips the inside surface's normals and creates a second outer shell around (some solid/watertight but hollow object). Subtract vein and artery object now...

I'm just a user as you are. Being no Autodesk employee: I do not know where this road will lead to, nor do I claim to've all stuff got right.