# Mesh does not have a valid dimension as a plotting domain in 11.0

In Version 11.0, it appears that one cannot plot over a mesh. The following code worked in Version 10.2:

\$Version
<< NDSolveFEM
reg = Rectangle[];
mesh = ToElementMesh[reg];
Plot3D[x^2 + y^2, Element[{x,y}, mesh]]


11.0.1 for Microsoft Windows (64-bit) (September 20, 2016)

Plot3D::idomdim: {x,y} ∈ mesh does not have a valid dimension as a plotting domain.

Of course I could have used Element[{x,y}, reg] as the plotting domain in this example, but I am working with a complicated mesh built from a BoundaryMesh rather than a region.

Similar behaviour has been observed in (144610) but this was not the question (and it was only an issue for the answerer zhk, who must have been using a different version of Mathematica to the OP).

• It works like a breeze in version 11.3 for macOS, but I recall that version 11.0.1 was quite buggy when it came to MeshRegion and BoundaryMeshRegion. Aug 6, 2018 at 6:33
• mesh is an NDSolveFEMElementMesh a different creature entirely, and wasn't completely supported in viz functions in 11.0. But, it works fine in 11.1. you need to convert to a MeshRegion via MeshRegion@mesh, but the results are "interesting" in 11.0. Aug 6, 2018 at 15:22

Needs["NDSolveFEM"]