--- jupyter: description: 'planex2d faces become netgen geometries in one call: names become materials and boundary conditions, and maxh and hpref control the mesh that netgen makes.' --- # netgen and NGSolve

The potential flow around a cylinder in a channel, solved with NGSolve on the mesh of a planex2d face

A potential flow on the mesh of a planex2d face

The temperature of a cold plate with four bores, a planex2d measurement solved by NGSolve

A cold plate's temperature as a measurement

An auxetic lattice tiled from a level set unit cell, extruded and loaded, its displacement in color

An auxetic lattice from a level set, loaded

planex2d faces and shapes become netgen geometries in one call. The geometry reaches netgen through OpenCASCADE, in the build that netgen ships as `netgen-occt`, so everything on the [OpenCASCADE](../occ/index.md) pages applies here too, and every plane argument takes netgen's `occ.Axes` besides a `px.Plane`. Face names turn into materials, edge names into boundary conditions, and vertex names into point names. `maxh` and `hpref` on faces, edges and vertices set the mesh size and refine towards corners. Faces glued into a shape share their edges, so the regions of the mesh fit together without gaps. Results come back onto the geometry: `px.PlotField` draws NGSolve and FEniCSx fields on the exact planex2d geometry, also in cuts through 3D parts. A measurement can pass the part to netgen for meshing and to NGSolve for solving, and `px.FromLevelSet` turns a level set function into a planex2d shape.

In this section

## Getting started - [Coming from netgen's WorkPlane](workplane.md) - [Naming and marking](naming.md) - [Identifications](identifications.md)

Coming from netgen's WorkPlaneDrawing code for netgen's WorkPlane run unchanged on px.WorkPlane, or taken over with px.FromOCC.

Naming and markingNames, mesh sizes and refinement set while drawing or afterwards, and how netgen reads them.

IdentificationsPeriodic unit cells and rotational sectors, with the transformation found automatically.

## Meshing and fields - [Meshing a face](meshing.md) - [Fields and cuts](fields.md) - [Solids and meshes in the webgui](webgui.md) - [Field solvers as measurements](field-solvers.md) - [From level sets](levelset.md)

Meshing a faceA named planex2d face meshed by netgen, with a potential flow, regions and corner refinement.

Fields and cutsTemperatures, fluxes, arrows and field lines on curved meshes and in cuts through 3D parts.

Solids and meshes in the webguiOpenCASCADE solids from planex2d faces and the meshes netgen makes of them.

Field solvers as measurementsPeak temperature and stress concentration as numbers on a sketch, checked against closed forms.

From level setsThe region where a level set function is positive, as a planex2d shape, shown on an auxetic lattice.