D3DXMatrixLookAtRH function (D3dx9math.h)

Builds a right-handed, look-at matrix.

Syntax

D3DXMATRIX* D3DXMatrixLookAtRH(
  _Inout_       D3DXMATRIX  *pOut,
  _In_    const D3DXVECTOR3 *pEye,
  _In_    const D3DXVECTOR3 *pAt,
  _In_    const D3DXVECTOR3 *pUp
);

Parameters

pOut [in, out]

Type: D3DXMATRIX*

Pointer to the D3DXMATRIX structure that is the result of the operation.

pEye [in]

Type: const D3DXVECTOR3*

Pointer to the D3DXVECTOR3 structure that defines the eye point. This value is used in translation.

pAt [in]

Type: const D3DXVECTOR3*

Pointer to the D3DXVECTOR3 structure that defines the camera look-at target.

pUp [in]

Type: const D3DXVECTOR3*

Pointer to the D3DXVECTOR3 structure that defines the current world's up, usually [0, 1, 0].

Return value

Type: D3DXMATRIX*

Pointer to a D3DXMATRIX structure that is a right-handed, look-at matrix.

Remarks

The return value for this function is the same value returned in the pOut parameter. In this way, the D3DXMatrixLookAtRH function can be used as a parameter for another function.

This function uses the following formula to compute the returned matrix.

zaxis = normal(Eye - At)
xaxis = normal(cross(Up, zaxis))
yaxis = cross(zaxis, xaxis)

 xaxis.x            yaxis.x            zaxis.x           0
 xaxis.y            yaxis.y            zaxis.y           0
 xaxis.z            yaxis.z            zaxis.z           0
 -dot(xaxis, eye)   -dot(yaxis, eye)   -dot(zaxis, eye)  1

Requirements

See also

Math Functions

D3DXMatrixLookAtLH