# extrude

Vertically extrude 2-D geometry or specified faces of 3-D geometry

## Description

`extrude(`

extrudes specified faces of a 3-D geometry along the direction normal to the faces. Here,
`g`

,`FaceID`

,`height`

)`FaceID`

specifies which faces to extrude. You can extrude faces into
multiple layers by specifying `height`

as a vector of thicknesses of the
layers.

All of the specified faces must be flat and have the same orientation. The extruded volumes must not intersect with each other or with the existing geometry.

returns a handle
`h`

= extrude(___)`h`

. If the original geometry is a `DiscreteGeometry`

object, then the function modifies the original geometry, and `h`

a
handle to the modified `DiscreteGeometry`

object. If the original geometry
is an `AnalyticGeometry`

object, then `h`

is a handle to
a new `DiscreteGeometry`

object. In this case, the original geometry
remains unchanged.

## Examples

## Input Arguments

## Output Arguments

## Tips

`extrude`

modifies a geometry, but it does not modify the corresponding mesh. After modifying a geometry, regenerate the mesh to ensure a proper mesh association with the new geometry.If a 2-D geometry has new vertices added by using the

`addVertex`

function,`extrude`

replicates the new vertices on each new layer of the extruded 3-D geometry, but it does not connect these vertices by edges.If

`g`

is an`AnalyticGeometry`

object, and you want to replace it with the extruded discrete 3-D geometry, assign the output to the original geometry, for example,`g = extrude(g,20)`

.

## See Also

DiscreteGeometry Properties | AnalyticGeometry Properties | `addVertex`

| `addFace`

| `pdegplot`

| `importGeometry`

| `generateMesh`

| `multicuboid`

| `multicylinder`

| `multisphere`

**Introduced in R2020b**