py2dm 0.1.1

Read and write 2DM mesh files

Py2DM

A Python module for reading and writing SMS 2DM mesh files.

Documentation

This project's documentation is hosted at Read the Docs.

Supported 2DM Cards

This module currently only supports a small subset of the cards defined in the 2DM format specification. If your use-case requires support of additional cards, feel free to get in touch via the repository issues.

Card	Description	Python representation
MESH2D	File format identifier	-
NUM_MATERIALS_PER_ELEM	The number of material IDs per element	-
ND	A 3D mesh node	Node
NS	A line string connecting nodes	NodeString
E2L	Two-noded line element	Element2L
E3L	Three-noded linear element	Element3L
E3T	Three-noded triangular element	Element3T
E6T	Six-noded triangular element	Element6T
E4Q	Four-noded quadrilateral element	Element4Q
E8Q	Eight-noded quadrilateral element	Element8Q
E9Q	Nine-noded quadrilateral element	Element9Q

Getting Started

Note: Please note that this module is in very early stages of development and is subject to heavy changes. Be sure to specify the exact version to use with your projects until this disclaimer is removed as there is not stable API yet.

Reading 2DM Files

Reading is performed via the py2dm.Reader class and its attributes nodes, elements, and node_strings. Alternatively, you can use their iterator equivalents iter_nodes(), iter_elements(), and iter_node_strings(), which are preferable for large meshes due to the reduced memory footprint.

with py2dm.Reader('path/to/mesh.2dm') as mesh:
    for node in mesh.iter_nodes():
        if node.id % 10 == 0:
            print(node)

# The above will print the following:
Node #10: (1200.0, 200.0, 20.0)
Node #20: (1120.0, 220.0, 10.0)
...

Writing 2DM Files

The py2dm.Writer class provides the node(), element(), and node_string() factory methods to add new geometries to the mesh. The factories for nodes and elements will return the ID they were assigned.

After adding your geometries, use the py2dm.Writer.write() method to commit the geometries to file.

with py2dm.Writer('path/to/mesh.2dm') as mesh:
    # Create nodes
    for i in range(10):
        mesh.node(float(i), 1.0, i % 2)
    # Create elements
    mesh.element(py2dm.Element2L, (1, 2))
    mesh.element(py2dm.Element3T, (1, 2, 3))
    # Save mesh
    mesh.write()