# XMPlaneNormalizeEst function

Estimates the coefficients of a plane so that coefficients of x, y, and z form a unit normal vector.

## Syntax

```
XMVECTOR XM_CALLCONV XMPlaneNormalizeEst(
FXMVECTOR P
);
```

## Parameters

`P`

**XMVECTOR** describing the plane coefficients (A, B, C, D) for the plane equation `Ax+By+Cz+D=0`

.

## Return Value

Returns an estimation of the normalized plane as a 4D vector whose components are the plane coefficients (A, B, C, D)
for the plane equation `Ax+By+Cz+D=0`

.

## Remarks

`Est`

functions offer increased performance at the expense of reduced accuracy.
`Est`

functions are appropriate for non-critical calculations where accuracy can be sacrificed for speed.
The exact amount of lost accuracy and speed increase are platform dependent.

### Platform Requirements

Microsoft Visual Studio 2010 or Microsoft Visual Studio 2012 with the Windows SDK for Windows 8. Supported for Win32 desktop apps, Windows Store apps, and Windows Phone 8 apps.## Requirements

Target Platform |
Windows |

Header |
directxmath.h |