surfaceFeatureExtract trims all features on a brick when minElem > 1
Summary
Not sure if this is a bug report of a feature request, but here it goes.
When I extract features on a brick defined by an stl file, the edge features (12 of them) only get extracted if trimFeatures minElem is not used or set to something not higher than 1. Since all the features are "connected" on the brick, I would have expected features to not be trimmed until at least a value of 13 on minElem.
This probably gets into how you are determining the number of elements in feature strings. In other software I've used, they generally separate things into "connected" feature groups and then apply element filtering to each of those. For example, a brick would have 12 connected feature edges and be in one group, so a minElem of 2 shouldn't trim any of the features, but in surfaceFeatureExtract, it does.
Steps to reproduce
Run surfaceFeatureExtract on the attached brick model. No features will be extracted because minElem is set to 2. If you set it to 1, the features get extracted.
Example case
What is the current bug behaviour?
No features will be extracted because minElem is set to something above 1.
What is the expected correct behavior?
I would expect all features to be extracted until minElem reaches 13, since there are 12 connected feature edges on a brick.
Environment information
OpenFOAM version : v1906
Operating system : RHEL / Windows
Compiler : gcc / MinGW
Possible fixes
I looked in surfaceFeatures.C to try and glean how feature strings were being determined, but I was unable to decipher the strategy being used. My guess is that there is a difference in strategy, if that's the case, then this is a feature request.
## Reattaching the author to the issue ticket: @graups ##