5.2.3 Flips

Figure 5.13: Issues with element flips across instances

The triangles in the structure instance on the top highlighted in red cannot be flipped, because this would break the geometry-conformity of the template $X_1$.

Flipping operations (cf. Section 3.2.1) can safely be performed for all elements in a mesh template, because they do not alter the boundary. However, flipping elements in ${\operatorname{AT}}({\Gamma})$, which are in at least two different mesh instances, is generally not possible as visualized in Figure 5.13, because they break the conformity and/or the geometry-conformity of the templated structure.