[Gmsh] Different threshold fields around one attractor

[Moritz Nadler]

Christophe Geuzaine wrote:

> Hi Moritz - You take the minimum of all fields with Field[5]. So you 
> will never see the 0.1 max char length from Field[4] (since you impose a 
> smaller one, 0.005, outside Field[2].DistMax).
> 
> Just change
> 
> Field[2].LcMax = 0.005;
> 
> into
> 
> Field[2].LcMax = 0.1;

Thanks for your answer.

I tried the modification you told me already for myself (of course I tried it 
again after your email) but it does not give the the result I want. I produces a 
mesh density that looks like this:


Mesh density
^
| ----------------|
|                 |
|                 |
|                 |
|                 --------------
|                               \
|                                \
|                                 \
|                                  -------------
|
|                 ^ DistMin 1
|                     ^ DistMax 1
|                               ^ DistMin 2
|                                  ^ DistMax 2
_________________________________________________> Distance from attractor


But what I want is this:


Mesh density
^
| ----------------
|                 \
|                  \
|                   \
|                    -----------
|                               \
|                                \
|                                 \
|                                  -------------
|
|                 ^ DistMin 1
|                     ^ DistMax 1
|                               ^ DistMin 2
|                                  ^ DistMax 2
_________________________________________________> Distance from attractor


Description of drawings:
DistMin 1 and DistMax 1 corresponds to Field[2].DistMin and Field[2].DistMax
and DistMin 2 and DistMax 2 correponds to Field[4].DistMin and Field[2].DistMax 
in my example file attached to this email.



After changing
Field[2].LcMax = 0.005;
to
Field[2].LcMax = 0.1;
the
Field[2].DistMax = 0.2;
command is ignored. Instead of a slow mesh density gradient from DistMin of 
Field 2 to DistMax of Field 2 the mesh density almost instantly changes from 
LcMin of Field 2 to LcMin of Field 4 at DistMin of Field 2.


I only used the MinField because I want both threshold fields to be used. If I 
use one of the threshold fields as a backround field the other one will be 
totally ignored. I do not want that some mimimum values of something are taken.
All the values the 2 threshold fields should be taken as I stated them.

Does anybody know how I could produce my desired mesh?
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