How to refine grids at special points

[Amors]

Hi, sir.
Hello,

I construct a plane and mesh it with Triangular element that are green lines in image

Weixin Image_20240321211906.png (16.77 KiB) Viewed 5718 times

. But now I need more grids (or smaller grid sizes) at special points that are the black dots in image. I don't know how to get it. I guess that I don't connect the points with the plane. Acturally, I don't know whether this function can be achieved in GID bucause I can't assign the sizes of the points to control the grid density around the points.

Best wishes!

[escolano]

Instead the original surface you can create another modified geometry creating the points at these forced node locations, connect them with lines and surfaces.

or alternatively can create the points and force to be on the mesh of the original surface with
Mesh->Mesh criteria->Force points to->Surface
select the surface, then the points to be forced to be mesh nodes
and generate the mesh
but this method can provide a worst mesh if you have a lot of points forced, or they are too close

[Amors]

Okay, I build the lines at original point locations and I achieve the results that some smaller grids are generated ( as seen in following Fig. ). But I note that the tetrahedron grids around lines have poor quality. I try to control the size of lines and growth factors from line to surface. Now, I still can’t obtain the good grids around lines.