Face fields

Figure 184: Node per face relationship

Faces are stored in field ifac(1..4,*). For a given node i ipofa(i) points to a face in ifac for which i is the lowest node number. The node numbers of this face are stored in entries ifac(1..3,ipofa(i)) in ascending order. The entry ifac(4,ipofa(i)) points to another face for which node i is also the lowest node, if any. If there exists no face for which i is the lowest node number ipofa(i)=0 (Figure 184). The scalar ifreefa points to a free entry in field ifac. For any line j in ifac which is not used yet ifac(4,j) points to the next free entry.

Other fields with a similar number of lines as ifac are itetfa, planfa and iexternfa. They contain:

All these fields (except the external ones) are dynamically adjusted during mesh refinement.