Parameter DIR in DEFINE_COORDINATE_SYSTEM December 9, 2013 | by Suri Bala LS-DYNA In earlier versions of LS-DYNA, the axis N1-N2 was always set as the local-x but in new versions (since LS-DYNA v971), the N1-N2 vector can be configured to be either X,Y,or Z. Image below shows the influence of DIR in the local system set up.