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[snappyHexMesh] Reducing STL size for snappyHexMesh

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Old   February 26, 2023, 11:10
Default Reducing STL size for snappyHexMesh
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Marcus
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Hi all,

I am currently working on a porous media problem where I am attempting to run pore-scale simulations using an STL model that was produced from X-Ray tomography.

Unfortunately, the file size can be large ~15-30gb and makes it difficult to work with. I've tried decimating and smoothing the STL file in Blender and ParaView, however, it almost always results in a bad-quality mesh (the original file produces OK mesh). In my case, bad quality means high aspect ratio cells, zero area face, zero volume cell, non-orthogonal faces and high max skewness. I've linked to a google drive that has a modified STL file (small segment of entire STL), decimated STL with 90% reduction and a template of the snappyHexMeshDict.
https://drive.google.com/drive/folde...bI?usp=sharing
Does anyone have any tips or recommendation in the best way to reduce the STL size without affecting the mesh produced by SHM.

Thanks,
Marcus
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Old   February 27, 2023, 03:41
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Yann
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Hello Marcus,

I don't know if it can do the trick for you, but SHM can deal with both STL and OBJ file formats, and OBJ format tends to be significantly lighter than STL.

(STL only contains triangle faces while OBJ works with polygons)

I hope this helps,
Yann
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Old   March 6, 2023, 03:45
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Quote:
Originally Posted by MarcusAng View Post
Hi all,

I am currently working on a porous media problem where I am attempting to run pore-scale simulations using an STL model that was produced from X-Ray tomography.

Unfortunately, the file size can be large ~15-30gb and makes it difficult to work with. I've tried decimating and smoothing the STL file in Blender and ParaView, however, it almost always results in a bad-quality mesh (the original file produces OK mesh). In my case, bad quality means high aspect ratio cells, zero area face, zero volume cell, non-orthogonal faces and high max skewness. I've linked to a google drive that has a modified STL file (small segment of entire STL), decimated STL with 90% reduction and a template of the snappyHexMeshDict.
https://drive.google.com/drive/folde...bI?usp=sharing
Does anyone have any tips or recommendation in the best way to reduce the STL size without affecting the mesh produced by SHM.

Thanks,
Marcus
Hi Marcus,

Element quality of surface stl is good, when I see your picture and stl file. Problem is not with decimation, it may be due to very small gaps, spaces etc.
You need to find the where these cells are and try to correct the surfaces there. You can also play with snappyhexmesh dict to overcome this.

Regards
Maries
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