Ditectx 90 basic 3D Transformation Function

Basic Transformation

Translation matrix)

D3DX function used to create the translation matrix

D3DXMATIX * D3DXMatrixTranslation (

D3DXMATRIX * pOut, // result

FLOAT x, // Number of units to translate on x-axis

FLOAT y, // Number of units to translate on y-axis

FLOAT z // Number of units to translate on z-axis

)

Rotation matrix)

D3DXMATRIX * D3DXMatrixRotationX (

D3DXMATRIX * pOut, // result

FLOAT Angle // Angle of rotation measured in radians

};

Proportional Transformation Matrix(Scaling Matrix)

D3DXMATRIX * D3DXMatrixScaling (

D3DXMATRIX * pOut, // result.

FLOAT sx, // Number of units to translate on x-axis

FLOAT sy, // Number of units to translate on y-axis

FLOAT sz // Number of units to translate on z-axis

);

 Vector transformation Functions

The D3DXVec3TransformCoord function transforms the point and assumes that the first component of the vector is 1.

D3DXVECTOR * D3DVXec3TransformCoord (

D3DXVECTOR3 * pOut, // result

CONST D3DXVECTOR3 * pv, // The point to transform

CONT D3DXMATRIX * pM // The transformation matrix

);

D3DXMATRIX T (...); // Initialize a transformation matrix

D3DXVECTOR p (...); // Initialize a point

D3DXVec3TransformCoord (& p, & p, & T); // transform the point

D3DXVec3TransformNormal is used for vector transformation, and assuming that the first part of the trace is 0

D3DXVECTOR3 * D3DXVec3TransformNormal (

D3DXVECTOR3 * pOut, // result.

CONST D3DXVECTOR3 * pv, // The vector to transform

CONT D3DXMATRIX * pM // The transformation matrix

);

D3DXMATRIX T (...); // Initialize a transformation matrix

D3DXVECTOR v (...); // Initialize a vector

D3DXVec3TransformCoord (& v, & v, & T); // transform the point

Function used for vertex Array

D3DXVECTOR3 * WINAPI D3DXVec3TransformCoordArray (

D3DXVECTOR3 * pOut,

UINT OutStride,

CONST D3DXVECTOR3 * pV,

UINT VStride,

CONST D3DXMATRIX * pM,

UINT n

);

POut

[In, out] Pointer to the D3DXVECTOR3 structure that is the result of the operation.

OutStride

[In] Stride between vectors in the output data stream.

PV

[In] Pointer to the source D3DXVECTOR3 array.

VStride

[In] Stride between vectors in the input data stream.

PM

[In] Pointer to the source D3DXMATRIX structure.

N

[In] Number of elements in the array.

Used for Vector Array Transformation:

D3DXVECTOR3 * WINAPI D3DXVec3TransformNormalArray (
D3DXVECTOR3 * pOut,

UINT OutStride,

CONST D3DXVECTOR3 * pV,

UINT VStride,

CONST D3DXMATRIX * pM,

UINT n

);

POut

[In, out] Pointer to the D3DXVECTOR3 array that is the result of the operation.

OutStride

[In] Stride between vectors in the output data stream.

PV

[In] Pointer to the source D3DXVECTOR3 array.

VStride

[In] Stride between vectors in the input data stream.

PM

[In] Pointer to the source D3DXMATRIX structure. To transpose a normal with a non-affine matrix, this matrix shocould be a transposed-inverse transformation matrix.

N

[In] Number of elements in the array.

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DirectX 9.0 3D Game Development Programming Basics

Jiangxi University of Technology FangSH 2010-4- Organize