Menu: Mesh→Semi-structured->Volumes
A semi-structured mesh can be assigned to a volume, which has to be topologically prismatic. That is: there can be recognized two top surfaces, and a set of lateral four-sided surfaces connecting them. This kind of mesh is structured in only one direction of the volume and is unstructured in the other two directions. For example, in a prismatic volume, the meshing on the sides of the object can be structured, while the meshing on the top surfaces can be unstructured. The top surfaces must be topologically equal. This implies they must have the same number of contour lines, but they can have different shape.
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