2D Meshes can be created 3 different ways in GMS: using an automatic meshing technique, manually entering the node locations and triangulating, or converting a different GMS data type to a 2D Mesh.
Map -> 2D Mesh is the preferred method for mesh generation in GMS.
In order to create a 2D Mesh in GMS you must have a set of 2D Mesh nodes. Elements can be created by using one of the create element tools and then selecting the mesh nodes to create elements. A 2D Mesh can also be created by triangulating the nodes. The triangulation algorithm assumes that each of the vertices being triangulated is unique in the xy plane, i.e. no two points have the same xy location. Duplicate points can be removed by selecting Find Duplicates command from the Mesh menu.
A 2D Mesh can be created manually from the following steps:
Select the Create Nodes tool from the Tool Palette.
Create the nodes by clicking inside the Graphics Window at the xy coordinates where you want the vertex located. (To change the node location see Editing Node Coordinates)
Select the Create Linear Triangle Element tool from the Tool Palette.
TINs, 2D grids, 2D scatter points, and 3D meshes can all be converted to a 2D Mesh. This is accomplished by using the following commands:
After using the Scatter Points -> Mesh Nodes command you must triangulate the nodes to create the 2D Mesh.
2D Mesh Module