Here is a hackish example which gives Isocaps:
using Meshing
using GeometryTypes
gyroid(v) = cos(v[1])*sin(v[2])+cos(v[2])*sin(v[3])+cos(v[3])*sin(v[1])
gyroid_shell(v) = max(gyroid(v)-0.4,-gyroid(v)-0.4)
xr,yr,zr = ntuple(_->LinRange(0,pi*4,50),3)
A = [gyroid_shell((x,y,z)) for x in xr, y in yr, z in zr]
A[1,:,:] .= 1e10
A[:,1,:] .= 1e10
A[:,:,1] .= 1e10
A[end,:,:] .= 1e10
A[:,end,:] .= 1e10
A[:,:,end] .= 1e10
gy_mesh = GLNormalMesh(A, MarchingCubes())
# view with Makie
import Makie
using LinearAlgebra
Makie.mesh(gy_mesh, color=[norm(v) for v in gy_mesh.vertices])
