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我一直在寻找D3DXVec3Transform和D3DXVec3TransformCoord函数如何操作,想知道这是否是数学的正确方法,如果不是的话,是否有人可以解释为什么。我知道已经有DirectX函数可以做到这一点,但是,我一直试图更多地了解幕后数学和我从这方面进行的研究。这是你如何正确计算Vector3变换和变换坐标?
D3DXVECTOR3 Vec3Transform(D3DXVECTOR3 &vCoordinate, D3DXMATRIX &mTransform)
{
D3DXVECTOR3 vWorking;
vWorking.x = (vCoordinate.x * mTransform._11) + (vCoordinate.y * mTransform._21) + (vCoordinate.z * mTransform._31) + mTransform._41;
vWorking.y = (vCoordinate.x * mTransform._12) + (vCoordinate.y * mTransform._22) + (vCoordinate.z * mTransform._32) + mTransform._42;
vWorking.z = (vCoordinate.x * mTransform._13) + (vCoordinate.y * mTransform._23) + (vCoordinate.z * mTransform._33) + mTransform._43;
return D3DXVECTOR3(vWorking.x, vWorking.y, vWorking.z);
}
D3DXVECTOR3 Vec3TransformCoordinate(D3DXVECTOR3 &vCoordinate, D3DXMATRIX &mTransform)
{
D3DXVECTOR4 vWorking;
vWorking.x = (vCoordinate.x * mTransform._11) + (vCoordinate.y * mTransform._21) + (vCoordinate.z * mTransform._31) + mTransform._41;
vWorking.y = (vCoordinate.x * mTransform._12) + (vCoordinate.y * mTransform._22) + (vCoordinate.z * mTransform._32) + mTransform._42;
vWorking.z = (vCoordinate.x * mTransform._13) + (vCoordinate.y * mTransform._23) + (vCoordinate.z * mTransform._33) + mTransform._43;
vWorking.w = 1/((vCoordinate.x * mTransform._14) + (vCoordinate.y * mTransform._24) + (vCoordinate.z * mTransform._34) + mTransform._44);
return D3DXVECTOR3(vWorking.x * vWorking.w, vWorking.y * vWorking.w, vWorking.z * vWorking.w);
}
D3DXMATRIX是一个4x4矩阵,是否会改变你对答案的看法? – judeclarke 2011-12-31 03:32:41