Metamaterials

OpenVCAD represents architected materials by separating a reusable unit cell from the cell map that places and deforms its repetitions. The same TPMS or graph cell can therefore be tiled in a rectangular block, graded across a part, clipped by ordinary geometry, or mapped onto CAD faces without changing its topology.

This section assumes you have completed Getting Started and Functional Grading. It is written for researchers and engineers who already work with lattice structures and want to understand OpenVCAD’s map-first Python workflow.

Guide sequence

Guide	Focus	Primary Python interfaces
Concepts and representation	Unit cells, TPMS fields, graph cells, and the role of a CellMap	ImplicitUnitCell, GraphUnitCell, CellMap
TPMS and lattice catalog	Built-in cells, their parameters, and filling ordinary geometry	tpms, graph_lattice, named builders
Attribute-driven metamaterials	Composing attributes to grade geometry, spacing, topology, and materials	FloatAttribute, Vec3Attribute, DerivedFloatAttribute, CellMap
Conformal mapping CAD surfaces	CAD authoring, face selection, and curved cell maps from exact surfaces	CADModel, cell_map_from_cad_face, cell_map_between_cad_faces
Conformal mapping triangle meshes	Flattened triangle-mesh patches, trimming to the true boundary, and mesh/CAD pairing	TriangleMeshSurface, cell_map_from_surface, cell_map_between_surfaces
Heterogeneous conformal lattices	Sharp, mixed, and overlapping topology regions on one shared map	Intersection, Union, Mix, CellMap
Geometric characterization	Density, surface, channel, section, connectivity, topology, and graph metrics	properties.characterize, properties.characterize_graph_cell

Read the concepts page first if the map-first representation is new to you. The catalog and attribute-driven guide can then be used independently; the conformal guides build on both.

Metamaterials guides

• Concepts and representation
  • Unit cells describe topology
  • Cell maps describe layout
  • Mapped cells become ordinary OpenVCAD nodes
• TPMS and lattice catalog
  • Build a finite rectangular map
  • TPMS catalog
  • Graph lattice catalog
  • Fill ordinary geometry
  • Parameter summary
• Attribute-driven metamaterials
  • Compose scalar attributes
  • Grade TPMS wall thickness
  • Change cell spacing
  • Grade beams, joints, faces, and plates
  • Compose vector attributes
  • Coordinates follow the geometry that uses them
  • Choose coordinates from the CellMap
  • Express a movement in cell units
  • Use one control for geometry and sampled data
  • Mix unit cells with a scalar control
  • Grade material distribution
• Conformal mapping CAD surfaces
  • Install the optional CAD authoring stack
  • How a face becomes a cell map
  • Author and select a CadQuery face
  • Map between two faces
  • Import STEP and select a face
  • Create other surface shapes
  • Validation is always final
• Map lattices onto triangle meshes
  • What the patch must be
  • How the patch becomes a chart
  • Trimming to the true boundary
  • Choosing the chart orientation
  • Map a procedural patch
  • Select a region of an imported mesh
  • Pair a mesh with a CAD surface
  • Limitations and troubleshooting
• Heterogeneous conformal lattices
  • Build sharp topology regions
  • Mix compatible topology fields smoothly
  • Connect incompatible topologies with overlap
  • Keep the shared layout on CAD surfaces
  • Choose sharp clipping, field mixing, or overlap
• Geometric characterization
  • Characterize any OpenVCAD design
  • What the report contains
  • Read directional cross-sections
  • Characterize a graph unit cell exactly
  • Control accuracy with voxel_size