Hi,

Was this feature eventually included in dolfinx? I just tried to do it in the way described in old docs and it didn’t work. Here is an MWE

```
import gmsh, dolfinx, ufl, mpi4py, petsc4py
import numpy as np
from dolfinx.io import gmshio
a = 1
L = 8*a
c1 = (L/2, L/2) # center of circle in first geometry
c2 = (L/2+0.1, L/2) # center of circle in second geometry
Um = 1
gmsh.initialize()
gdim = 2
model_rank = 0
occ = gmsh.model.occ
rectangle = occ.addRectangle(0,0,0, L, L)
obstacle = occ.addDisk(c1[0], c1[1], 0, a, a)
occ.synchronize()
geom, _ = occ.cut([(gdim, rectangle)], [(gdim, obstacle)])
occ.synchronize()
domains = gmsh.model.getEntities(dim=gdim)
assert(len(domains) == 1)
gmsh.model.addPhysicalGroup(domains[0][0], [domains[0][1]], 1)
gmsh.model.setPhysicalName(domains[0][0], 1, "Fluid")
gmsh.model.mesh.generate(gdim)
gmsh.model.mesh.refine()
mesh1, ct1, ft1 = gmshio.model_to_mesh(gmsh.model, mpi4py.MPI.COMM_WORLD, model_rank, gdim=gdim)
gmsh.clear()
rectangle = occ.addRectangle(0,0,0, L, L)
obstacle = occ.addDisk(c2[0], c2[1], 0, a, a)
occ.synchronize()
geom, _ = occ.cut([(gdim, rectangle)], [(gdim, obstacle)])
occ.synchronize()
domains = gmsh.model.getEntities(dim=gdim)
assert(len(domains) == 1)
gmsh.model.addPhysicalGroup(domains[0][0], [domains[0][1]], 1)
gmsh.model.setPhysicalName(domains[0][0], 1, "Fluid")
gmsh.model.mesh.generate(gdim)
gmsh.model.mesh.refine()
mesh2, ct2, ft2 = gmshio.model_to_mesh(gmsh.model, mpi4py.MPI.COMM_WORLD, model_rank, gdim=gdim)
gmsh.finalize()
velocity = lambda x: 4*Um*x[1]*(L-x[1])
V1 = dolfinx.fem.FunctionSpace(mesh1, ("CG", 2))
u1 = dolfinx.fem.Function(V1)
u1.interpolate(velocity)
# now that we have u1 defined on mesh1, let us use it to define u2 on mesh2
V2 = dolfinx.fem.FunctionSpace(mesh2, ("CG",2))
u2 = dolfinx.fem.Function(V2)
u2.interpolate(u1)
```

Of course the last step u2.interpolate(u1) runs into error:

RuntimeError: Interpolation on different meshes not supported (yet).