Can snappyHexMesh handle intersecting geometries?
 

Hi all,

can snappyHexMesh handle geometries (closed STL/OBJ shells), that intersect each other? Will the algorithm identify these geometries as one and create a mesh around them, or I need to unite the two geometries?

Also, what happens when the geometry "sticks out" of the domain of the background mesh?

Thanks in advance!

If part of your geometry sticks out of the background mesh, that part will simply be cut off.

As for your question about intersecting geometries, I'm not sure what you're referring to. If, as I think, you mean that some part of your geometry overlaps, I'm not sure what sHM will do. I suspect you are correct in that it will consider only those regions which are unambiguously "outside" your geometry as outside, and anything else as "inside". But there's only really one way to find out. Try it! Let me know your result.

Hi Patrick, thanks for your input.
On intersecting I mean not only overlapping, but penetrating geometries (e.g. a cylinder goes into a cube). What will be meshed in this case? The union of the geometries, or the mesh will go inside somehow?
Hope somebody else can also make an input. Nevertheless, I will try it out on a simple geometry!

Hi Attesz,
old thread for sure, but i have the exact same question right now - so... beeing lazy to try my self (and for the sake of thread-completeness): Do you remember what your final conclusions were? Did you try it?

Yes - snappy handles intersecting geometries as they were united. The intersection will not necessarily be captured properly however. It is better to avoid intersection if possible and use one high quality closed surface mesh.

Thank you for the quick reply! So it seems that this is not a use-case of snappy and merely works by accident but may produce artifacts. Then I have to think of another solution, thanks again!