Question

我目前正在使用具有Viewport3D相机的wpf应用程序。我正在创建一个3D演练模块。我希望我的PerspectiveCamera根据Look Directions更改后面向的方向移动。我正在使用键盘控制机芯，例如：
NUMPAD8：向前迈进 NUMPAD2：向后移动
NUMPAD4：向左旋转
NUMPAD6：向右旋转

以下方法是检测键盘事件：

 private void button20_KeyDown(Object sender, KeyEventArgs e)
    {
        if (e.Key == Key.NumPad6)
        {
            Rotate(1);
        }
        else if (e.Key == Key.NumPad4)
        {
            Rotate(-1);
        }
        else if (e.Key == Key.NumPad8)
        {
            Move(-10);
        }
        else if (e.Key == Key.NumPad2)
        {
            Move(10);
        }
    }

这是计算轮换：

public void Rotate(double d)
    {
        double u = 0.05;
        double angleD = u * d;
        PerspectiveCamera camera = (PerspectiveCamera)Viewport3D.Camera;
        Vector3D lookDirection = camera.LookDirection;
        double L = lookDirection.Length;
        double D = 2 * L * Math.Sin(angleD / 2);
        double m = Math.Sqrt(lookDirection.X * lookDirection.X + lookDirection.Y * lookDirection.Y);
        double angleA = 2 * Math.Asin(D / (2 * m));
        double x = lookDirection.X;
        double y = lookDirection.Y;
        double angleB = Math.Atan2(y, x);
        double angleG = angleB - angleA;
        double newx = m * Math.Cos(angleG);
        double newy = m * Math.Sin(angleG);
        Vector3D NewlookDirection = new Vector3D(newx, newy, lookDirection.Z);
        camera.LookDirection = NewlookDirection;

    }

这是计算相机移动：

public void Move(double d)
    {
        double u = 0.05;
        PerspectiveCamera camera = (PerspectiveCamera)Viewport3D.Camera;
        Vector3D lookDirection = camera.LookDirection;
        Point3D position = camera.Position;
        //Point3D NewPosition = new Point3D();
        position.Y += d;
        //NewPosition.X = position.X + u * lookDirection.X * d;
        //NewPosition.Y = position.Y + u * lookDirection.Y * d;
        //NewPosition.Z = position.Z + u * lookDirection.Z * d;
        //camera.Position = NewPosition;
        camera.Position = position;
    }

旋转计算工作得很完美，但运动似乎不能正常工作，因为它会在旋转后根据摄像机位置而不是面向方向移动摄像机。

Answer 1

注释掉的代码看起来或多或少......你没有说出它的错误。你试过规范化lookDirection向量吗？归一化矢量使其幅度（长度）为1。

public void Move(double d)
{
    double u = 0.05;
    PerspectiveCamera camera = (PerspectiveCamera)Viewport3D.Camera;
    Vector3D lookDirection = camera.LookDirection;
    Point3D position = camera.Position;

    lookDirection.Normalize();
    position = position + u * lookDirection * d;

    camera.Position = position;
}

更新：

private void Window_KeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.NumPad6)
    {
        Rotate(10);
    }
    else if (e.Key == Key.NumPad4)
    {
        Rotate(-10);
    }
    else if (e.Key == Key.NumPad8)
    {
        Move(-10);
    }
    else if (e.Key == Key.NumPad2)
    {
        Move(10);
    }
    else if (e.Key == Key.PageUp)
    {
        RotateVertical(10);
    }
    else if (e.Key == Key.PageDown)
    {
        RotateVertical(-10);
    }
}
public void Rotate(double d)
{
    double u = 0.05;
    double angleD = u * d;
    PerspectiveCamera camera = (PerspectiveCamera)Viewport3D.Camera;
    Vector3D lookDirection = camera.LookDirection;

    var m = new Matrix3D();
    m.Rotate(new Quaternion(camera.UpDirection, -angleD)); // Rotate about the camera's up direction to look left/right
    camera.LookDirection = m.Transform(camera.LookDirection);
}

public void RotateVertical(double d)
{
    double u = 0.05;
    double angleD = u * d;
    PerspectiveCamera camera = (PerspectiveCamera)Viewport3D.Camera;
    Vector3D lookDirection = camera.LookDirection;

    // Cross Product gets a vector that is perpendicular to the passed in vectors (order does matter, reverse the order and the vector will point in the reverse direction)
    var cp = Vector3D.CrossProduct(camera.UpDirection, lookDirection);
    cp.Normalize();

    var m = new Matrix3D();
    m.Rotate(new Quaternion(cp, -angleD)); // Rotate about the vector from the cross product
    camera.LookDirection = m.Transform(camera.LookDirection);
}

将PerspectiveCamera移向C＃所面向的方向

1 个答案: