Grid generators incomplete

[termi-official]

Our set of grid generators is incomplete. We are missing generators for

• [ ] 2D serendipity
• [ ] "Quadratic" Tetrahedron
• [ ] "Quadratic" Hexhedron (Note: Some dispatches missing)

It also should not be too hard to generalize the generators to arbitrary order.

[koehlerson]

We don't have quadratic hexas implemented, only the serendipity in 3D and this has a grid generator: https://github.com/Ferrite-FEM/Ferrite.jl/blob/master/src/Grid/grid_generators.jl#L242

Embedded triangle is also not implemented right now

[termi-official]

I know, but implementing higher order Lagrange/hex is high on my TODO list, because I need them. :) What do you mean by embedded triangle?

[koehlerson]

I mean a triangle in 3D is not implemented yet, so there can't be a grid generator for it

[termi-official]

What do you mean? Using Cell{3,3,3} should work just fine, or am I missing something?

[koehlerson]

Cell{3,3,3} is not implemented yet with the dispatches on edges, faces, vertices is all I'm saying

[termi-official]

Probably a more elegant way to resolve part of this is to implement a method like "change_mesh_order" and just provide the first order generators.