For the cell vtkTriQuadraticHexahedron, the face numbering is defined here as
The mid-surface nodes lies on the faces defined by (first edge nodes id’s, than mid-edge nodes id’s): (0,1,5,4;8,17,12,16), (1,2,6,5;9,18,13,17), (2,3,7,6,10,19,14,18), (3,0,4,7;11,16,15,19), (0,1,2,3;8,9,10,11), (4,5,6,7;12,13,14,15)
* top
* 7--14--6
* | |
* 15 25 13
* | |
* 4--12--5
*
* middle
* 19--23--18
* | |
* 20 26 21
* | |
* 16--22--17
*
* bottom
* 3--10--2
* | |
* 11 24 9
* | |
* 0-- 8--1
I interpret this as follows:
front, right, back, left, bottom, top
But for higher order elements, explained in this pdf, the order in figure 8 seems to be
left,right,front,back,bottom,top.
I am guess that vtk use the same face order for all cells, so which one is wrong? or am I misinterpreting something?