MeshFile sphere_plan.msh

LevelSet 1 2 Function Scalar 0*x+0*y+1*z+0.2 [x,y,z]
LevelSet 2 2 Function Scalar sqrt((0-x)^2+(0-y)^2+(0-z)^2)-0.4 [x,y,z]

//Plane: define the plane _a*x+_b*y+_c*z+_d, with outward normal (_a,_b,_c)
//Sphere: define the sphere sqrt((_xc-x)^2+(_yc-y)^2+(_zc-z)^2)-_r, with center (_xc,_yc,_zc) and radius _r
//Cylinder: define the cylinder sqrt(((_xc-x)/_a)^2+((_yc-y)/_b)^2)-1, along z with center (_xc,_yc) and half-axes a and b