The thermal calculation with radiative heat transfer, conduction and elastic stress calculations can be done using only the unstructured mesh. The melt convection at small and moderate Reynolds numbers and species transport can also performed be on the unstructured mesh, but this is disencouraged now.

The structured mesh should be preferred for the convective heat transport
at higher Reynolds numbers and especially for the turbulent fluid
flow. The chemical model of *CrysMAS* works only on the structured
mesh.

The structured mesh generation in complex geometry is more elaborated than of the unstructured one. The structured mesh generation can begin after an unstructured mesh is already generated everywhere.

For details see the section "Structured mesh generation and adjustment" in the "Settings" chapter and the tutorial "Generating structured mesh in complex geometries" and Generating structured mesh in complex geometries. .