2013-10-29 37 views
1

我有以下功能代码:雷采摘方向不正确计算

D3DXVECTOR3 Mouse::GetClickDirection(D3DXMATRIX projMatrix, D3DXMATRIX viewMatrix, D3DXVECTOR3 cameraPosition) 
{ 
    POINT mousePoint; 
    GetCursorPos(&mousePoint); 

    ScreenToClient(hwnd, &mousePoint); 

    float x = ((mousePoint.x * 2.0f)/(float)backBufferWidth) - 1.0f; 
    float y = ((mousePoint.y * -2.0f)/(float)backBufferHeight) + 1.0f; 

    D3DXVECTOR3 mouseClip = D3DXVECTOR3(x, y, 1.0f); 

    D3DXMATRIX invViewMatrix; 
    D3DXMatrixInverse(&invViewMatrix, 0, &viewMatrix); 

    D3DXMATRIX invProjMatrix; 
    D3DXMatrixInverse(&invProjMatrix, 0, &projMatrix); 

    D3DXMATRIX inversedMatrix = invViewMatrix * invProjMatrix; 

    D3DXVECTOR3 mouseWorldSpace; 
    D3DXVec3TransformCoord(&mouseWorldSpace, &mouseClip, &inversedMatrix); 

    D3DXVECTOR3 direction = mouseWorldSpace - cameraPosition; 

    D3DXVec3Normalize(&direction, &direction); 

    system("CLS"); 
    std::cout << "sX: " << x << std::endl; 
    std::cout << "sY: " << y << std::endl; 

    std::cout << "X: " << direction.x << std::endl; 
    std::cout << "Y: " << direction.y << std::endl; 
    std::cout << "Z: " << direction.z << std::endl; 

    return direction; 
} 

我试图根据x和y的屏幕一点上,用户点击了在计算和创建一个定向光线我DirectX 3D应用程序。到目前为止,印刷的结果似乎表明我的计算是错误的,因为Z值总是在0.9左右,我不知道为什么。我在这里做错了什么?请帮忙。谢谢

+0

你知道,还有就是[D3DXVec3Unproject功能(http://msdn.microsoft.com/en-us/library/windows/desktop/bb205526(V = vs.85)的.aspx),做基本上这个? –

回答

2

我认为你的逆矩阵计算是倒退。

D3DXMATRIX inversedMatrix = invProjMatrix * invViewMatrix;