STL FIle Import (Complex Geometry): Resolution Query

[achodankar]

Hello Developers,
I am an importing a STL file with complex geometry. My query is how is the resolution and deltax value set in this case. How do I make relation with the no of triangles and no of points(resolution)? When I put N=1, I get the least no of points, but I fail to understand the relation between no of points and STL file.

Also the geometry formed fails to be symmetric after imported in openlb. Moreover, the way nodes are assigned material numbers gets messed up.

Here are the images:

https://ibb.co/4JDcjB3
https://ibb.co/K221NQq

I would really appreciate your feedback on this matter.

Thank you.

Yours sincerely,

Abhijeet C.

[achodankar]

Hello Developers,
The problem is seen when I import a 3d geometry consisting of curves. I tried with a circular and semicircular geometry, thereby facing the same issues for these geometries. Is there any particular part of openlb I should address to fix this issue? I would really appreciate your feedback.

Thank you.

Yours sincerely,

Abhijeet C.

[Adrian]

The resolution parameter N in examples is commonly w.r.t. some kind of characteristic length used during construction of the UnitConverter that yields the delta X value. You can see this if you check the usage of N in any of the examples.

[achodankar]

Hello Adrian,
I understand the usage of N in general examples wherein the geometry is created using indicators. The way we define N will determine the deltax value. However, I fail to understand how it will work when the geometry is imported using an STL file. The imported geometry has predetermined deltax value based on the triangulations. SolidWorks or FreeCAD will just spit out the STL files. How is Openlb communicating with these STL files and setting or resetting the deltax values based on a given N value?

Thank you.

Yours sincerely,

Abhijeet C.

[Adrian]

The STLreader accepts both the voxel size and the STL reference size as constructor parameters. See e.g. the doxygen documentation.

[achodankar]

Hello Adrian,
Thank you for your response. My apologies for the late reply.

What is the use of the method parameter?
Choose indication method 0: fast, less stable 1: slow, more stable (for untight STLs)

Thank you.

Yours sincerely,

Abhijeet C

[mathias]

Theses are different ray traying approches which are more or less robust and fast. Best Mathias

[achodankar]

Hello Mathias,
Thank you. I understand it well now.

Yours sincerely,

Abhijeet C.

[Author]

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