XMVector3Normalize function (directxmath.h)

Returns the normalized version of a 3D vector.

Syntax

XMVECTOR XM_CALLCONV XMVector3Normalize(
 [in] FXMVECTOR V
) noexcept;

Parameters

[in] V

3D vector.

Return value

Returns the normalized version of V.

Remarks

For a vector of length 0, this function returns a zero vector. For a vector with infinite length, it returns a vector of QNaN.

Note that for most graphics applications, ensuring the vectors have well-defined lengths that don't cause problems for normalization is common practice. However, if you need a robust normalization that works for all floating-point inputs, you can use the following code instead:

inline XMVECTOR XMVector3NormalizeRobust( FXMVECTOR V )
{
 // Compute the maximum absolute value component.
 XMVECTOR vAbs = XMVectorAbs(V);
 XMVECTOR max0 = XMVectorSplatX(vAbs);
 XMVECTOR max1 = XMVectorSplatY(vAbs);
 XMVECTOR max2 = XMVectorSplatZ(vAbs);
 max0 = XMVectorMax(max0, max1);
 max0 = XMVectorMax(max0, max2);

 // Divide by the maximum absolute component.
 XMVECTOR normalized = XMVectorDivide(V, max0);

 // Set to zero when the original length is zero.
 XMVECTOR mask = XMVectorNotEqual(g_XMZero, max0);
 normalized = XMVectorAndInt(normalized, mask);

 XMVECTOR t0 = XMVector3LengthSq(normalized);
 XMVECTOR length = XMVectorSqrt(t0);

 // Divide by the length to normalize.
 normalized = XMVectorDivide(normalized, length);

 // Set to zero when the original length is zero or infinity. In the
 // latter case, this is considered to be an unexpected condition.
 normalized = XMVectorAndInt(normalized, mask);
 return normalized;
}
 

Platform Requirements

Requirements

See also

DirectXMath Library 3D Vector Geometric Functions

XMVector3NormalizeEst