c++ - 光线拾取方向计算不正确

Question

我有以下功能代码:

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;
}

我正在尝试根据用户在我的 DirectX 3D 应用程序中单击的 x 和 y 屏幕点来计算和创建定向射线。到目前为止，打印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。我到底做错了什么？请帮忙。谢谢

Answer 1

我认为你的逆矩阵计算是倒退的。

D3DXMATRIX inversedMatrix = invProjMatrix * invViewMatrix;