# Three dimensional anisotropic mesh adaptive

hello
Sorry to bother you, recently, I tried to use Mshmet and MMG3D to generate three-dimensional anisotropic mesh, but the generated mesh anisotropy is not strong, that is, the mesh ratio is not very large, for example, run the following program,the mesh ratio of the resulting mesh is small. My question is how do you generate a more anisotropic grid? For example, the grid ratio can be on the order of 100000.
func f=10000x^2+10y^2+z^2;
int nn = 10;
int[int] lc=[1,2,2,1,1,2]; // label numbering
mesh3 Th=cube(nn,nn,nn,label=lc);
fespace Vh (Th,P1);
fespace Mh(Th,[P1,P1,P1,P1,P1,P1]);
Vh u=f;
Mh [m11,m21,m22,m31,m32,m33];
real lerr=0.05;
for(int i=0;i<7;i++)
{
[m11,m21,m22,m31,m32,m33]=[0,0,0,0,0,0];
real[int] met=mshmet(Th,u,hmin=1e-5,hmax=0.2,err=lerr,aniso=1);
m11[]=met;
Th=mmg3d(Th,metric=m11[]);
lerr *= 0.5;
mesh3 Th1=trunc (Th,(x<0.5|y<0.5|z<0.5),label=1);
if(i>5) medit(“Th1”+i,Th1,u,wait=1);
}
Thank you.

See the parameter of mmg, but a ration of 1e5 is hard to build .

Ok,thank you very much.

Hello,
I’m sorry to bother you again. There is still the problem of the grid ratio. You said before that it is difficult for the grid ratio to reach 1e5. Is there a way to solve this problem?
Thank you.