OPM/opm-core — pull request #1 by bska (2012-06-26 19:47:49+00:00)
Title: Bring in more resilient grid processing and geometry calculation

This change set brings a new, more resilient and feature-complete corner-point processing. In particular, the new code features exact, in-plane vertex coordinates for face nodes that arise as a result of fault processing and which are not located on pillars. Secondly, the resulting grid's cells are ordered lexicographically with the I index cycling the most rapidly, followed by J and finally K.

Finally, the first part of this patch also brings automatic handling of left-handed coordinate systems which, until now, have produced negative cell volumes as a result of face vertices being ordered such that interface normals point from cell 2 to cell 1 in this case. Left-handed coordinate systems are recognised using a simplistic triple-product characterisation akin to the implementation of function "processGRDECL" of MRST.

The second part of the patch removes a misleading diagnostic message concerning negative cell volumes. The message was printed too early and, as a result of accumulating signed tetrahedron volumes, would sometimes lead to false positives.

These refinements were tested on a model provided by Joakim Hove.