Boolean problem in salome

Mesh generators, CAD programs, and other tools
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tryphena
Posts: 35
Joined: 16 Apr 2021, 17:38
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Boolean problem in salome

Post by tryphena »

Hello,
I would like to ask something about the boolean problem in Salome. I have imported two STL files of cylinders in the geometry module, and performed difference operation. But it did not cut through. But in Blender, it can cut through. I tried more triangles for the cylinder mesh, but still not working. I wonder why this occurs? How could I fix it? Any idea?

Thank you in advance!

Here is the link for the files:
https://www.dropbox.com/sh/45aa42lz6ssf ... RZZWa?dl=0

Best wishes,
Tryphena
kevinarden
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Joined: 25 Jan 2019, 01:28
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Re: Boolean problem in salome

Post by kevinarden »

It is because of accuracy of the model representations, or geometric tolerances used between Salome and Blender. Salome is a geometric solid modeling tool, which by default uses much higher accuracy and geometric tolerance. Blender is a visualization tool that only uses enough accuracy to make it look good. Blender is defining the surfaces using faceted triangles, and although there is increased accuracy from using more triangles and facets, there is still an accuracy difference. In this case it is cutting but not the entire length. I loaded both in Salome and move Solid 1 in the X direction by -0.001 and then solid 2 cut all the way through. This demonstrates that there is a much larger tolerance in Blender than Salome, by default. You may be able to review the preferences in Blender and Salome to see if the tolerance values can be set to similar values.
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kevinarden
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Joined: 25 Jan 2019, 01:28
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Re: Boolean problem in salome

Post by kevinarden »

If the inner cylinder is just a cutting tool you could make it slightly longer than the outer tube to ensure it cuts all the way through.
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