[Gmsh] About defining different element size

[Liu David]

Dear all,
Greetings！
I am a new user in Gmsh. What I want is not complicated. I have an area of
which some part need more meshes and others need less. I tried to use two
approaches:
1. select and define some points need more meshes, and use Attractor and
Threshold to define a size field.
    However, I found that near the points(I uesd in Attractor to compute
distance), there are very dense meshes, and if zoom in, I found the very
near part are not triangles at all(strange things , even no closure shape)!
2. select and define some points need more meshes, and give them small
element size(lc), then embed them in the surface.
    However, I found even size are big enough, the meshes can not be sparse
since the points I define have to be the nodes of the triangles. Yes?

I write simple .geo files attached for illustration of the two problem.
Could you please help me ?   Thank you very much!

-- 
Best wishes!

Sincerely yours,
Liu Xiaoyu
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