# Creating PolygonMeshes

The **Mesh** command creates 3D PolygonMeshes. Usually it is used to generate irregular surfaces, vertex by vertex. For example, it is used in surveying and geographic information system applications to create topological surfaces.

A mesh is a wireframe rectilinear blanket composed of **M** column lines by **N** row lines passing through a matrix of **M** x **N** 3D points in space. **M** and **N** are indices that specify the number of rows and columns that make up the mesh and determine the number of vertices required in the mesh.

Meshes can be open or closed depending on whether the mesh joins in the **M** or **N** direction, or both. A donut mesh is an example of a mesh closed in both directions.

To create PolygonMeshes:

- Click
**Draw > Mesh > 3D Mesh**(or type**Mesh**). - Type a value for the size of the mesh in the
**M**direction. - Type a value for the size of the mesh in the
**N**direction.

You are prompted to specify the coordinates for corners of vertices until you have defined all vertices in the**M**and**N**directions. You are prompted for each vertex in order, starting with vertex (0,0), continuing with the second vertex in the first column (0,1), and so on. After you specify all vertices of a column, you are prompted for the first vertex of the next column. - Click in the graphics area or type the coordinates for each vertex.

Access

**Command: Mesh**

**Menu: Draw > Mesh > 3D Mesh**