# reducepatch

Reduce number of patch faces

## Syntax

`reducepatch(p,r)`

nfv = reducepatch(p,r)

nfv = reducepatch(fv,r)

nfv = reducepatch(p)

nfv
= reducepatch(fv)

reducepatch(...,'fast')

reducepatch(...,'verbose')

nfv = reducepatch(f,v,r)

[nf,nv] = reducepatch(...)

## Description

`reducepatch(p,r)`

reduces the number of
faces of the patch identified by handle `p`

, while
attempting to preserve the overall shape of the original object. The MATLAB^{®} software
interprets the reduction factor `r`

in one of two
ways depending on its value:

If

`r`

is less than 1,`r`

is interpreted as a fraction of the original number of faces. For example, if you specify`r`

as 0.2, then the number of faces is reduced to 20% of the number in the original patch.If

`r`

is greater than or equal to 1, then`r`

is the target number of faces. For example, if you specify`r`

as 400, then the number of faces is reduced until there are 400 faces remaining.

`nfv = reducepatch(p,r)`

returns the reduced set of faces and vertices but does not set the `Faces`

and `Vertices`

properties
of patch `p`

. The struct `nfv`

contains
the faces and vertices after reduction.

`nfv = reducepatch(fv,r)`

performs
the reduction on the faces and vertices in the struct `fv`

.

`nfv = reducepatch(p)`

and ```
nfv
= reducepatch(fv)
```

uses a reduction value of `0.5`

.

`reducepatch(...,'fast')`

assumes
the vertices are unique and does not compute shared vertices.

`reducepatch(...,'verbose')`

prints progress messages to the command window as the computation
progresses.

`nfv = reducepatch(f,v,r)`

performs
the reduction on the faces in `f`

and the vertices
in `v`

.

`[nf,nv] = reducepatch(...)`

returns
the faces and vertices in the arrays `nf`

and `nv`

.

## Examples

## Tips

If the patch contains nonshared vertices, MATLAB computes shared vertices before reducing the number of faces. If the faces of the patch are not triangles, MATLAB triangulates the faces before reduction. The faces returned are always defined as triangles.

The number of output triangles may not be exactly the number
specified with the reduction factor argument (`r`

),
particularly if the faces of the original patch are not triangles.

## Extended Capabilities

## Version History

**Introduced before R2006a**

## See Also

`isosurface`

| `isocaps`

| `isonormals`

| `smooth3`

| `subvolume`

| `reducevolume`