Comment 18 for bug 850864

Hi Klaus,
Thanks for the pointer.
After a quick look, it has strong similarities with what we are already planing (and what colleagues have implemented here in SDEC), the key feature being mutual exclusion of contacts on node/edge/facet based on a connectivity table.
The main difficulties are in the practical implementation more than in the conceptual algorithm.
For instance, the article present a global loop on interactions in order to eliminate mutually exclusive contacts. Fine, but there is currently no place for such loop in Yade. Instead, we have to split this loop into many local checks at each contact, so that the same series of checks is done at the end of the day.

One very important thing not adressed in the paper (or my look was too quick) is the fact that the same contact can persist while changing status during a tangent motion: sphere-edge1 -> sphere-facet -> sphere-edge2 - etc. This is really the tricky part.