(guide-metamaterials)=
# 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](../getting-started.md) and [Functional Grading](../gradients.md). 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](concepts.md) | Unit cells, TPMS fields, graph cells, and the role of a `CellMap` | `ImplicitUnitCell`, `GraphUnitCell`, `CellMap` |
| [TPMS and lattice catalog](catalog.md) | Built-in cells, their parameters, and filling ordinary geometry | `tpms`, `graph_lattice`, named builders |
| [Attribute-driven metamaterials](attribute-driven.md) | Composing attributes to grade geometry, spacing, topology, and materials | `FloatAttribute`, `Vec3Attribute`, `DerivedFloatAttribute`, `CellMap` |
| [Conformal mapping CAD surfaces](conformal-cad.md) | 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](conformal-meshes.md) | 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](heterogeneous-lattices.md) | Sharp, mixed, and overlapping topology regions on one shared map | `Intersection`, `Union`, `Mix`, `CellMap` |
| [Geometric characterization](properties.md) | 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.

```{toctree}
:maxdepth: 2
:caption: Metamaterials guides

concepts
catalog
attribute-driven
conformal-cad
conformal-meshes
heterogeneous-lattices
properties
```