SCOREC
Element quality with matched meshes
When running mesh adapt with matched meshes and lion print verbose, the following line is printed: Matched mesh: disabling snapping, and shape correction,
Is shape correction disabled throughout the entire mesh or only elements whose closure are classified on the matched model entities?
I am sure you can see where I am going with this. While I understand that there are algorithmic challenges to make quality controls like shape improvement work well when matching must be maintained, it would seem to me that existing algorithms could be applied for elements that do not contact the matched model boundaries.
In my application I am running mesh adapt every 50 steps for likely 10 or even 100,000 time steps and there is a steady degradation of element quality. While some of the problems are at the matched boundaries, the worst ones are in the interior, not even close to the boundary and it would seem to me that these would certainly benefit from shape correction.
Here are a few paraview->meshQuality->edgeRatio->Threshold pics. Start with the Threshold 40 to see the nearly flattened triangle. Threshold 20, 10, and then 5 show potential cavities that could be created to improve the mesh quality (e.g., presumably remove the bad elements fully contained in the cavity and remesh the cavity). Not sure if this is "available" in the shape improvement tool kit but just sharing an observation regarding the degradation of elements even though I am making isotropic size requests that are within a range of 1 to 0.25 of the original mesh generated (not that factor per adapt cylcle...sizeReq is never smaller than 0.25* size_original_mesh).
The print statement is here: https://github.com/SCOREC/core/blob/28d22997d1b30d9b3cc04f417b040713d20eda81/phasta/phAdapt.cc#L42-L48
In maMatch.cc the following function appears to disable collapses and swaps on cavities that span the matched boundary. https://github.com/SCOREC/core/blob/28d22997d1b30d9b3cc04f417b040713d20eda81/ma/maMatch.cc#L79-L98
