Unity3D -使用Transform.LookAt时自上而下的相机逻辑被锁定

Question

我已经建立了一个自定义自上而下的相机逻辑脚本，基于Unity3D的ThirdPersonCamera.js脚本。一切看起来都正常工作，相机跟随目标玩家在XZ平面上，甚至在玩家跳跃时沿着Y轴移动。

只是摄像机没在盯着玩家看。因此，我尝试在cameraTransform上使用cameraTransform()让摄像机直接向下看播放机。这确实会导致相机在播放器上正确地向下看，但是通过WASD的移动不再有效。玩家就坐在那里。不过，使用Spacebar进行跳跃仍然有效。

这对我来说是没有意义的，相机变换的方向如何影响玩家物体的运动呢？

我的脚本的代码如下：

// The transform of the camera that we're manipulating
var cameraTransform : Transform;

// The postion that the camera is currently focused on
var focusPosition = Vector3.zero;

// The idle height we are aiming to be above the target when the target isn't moving
var idleHeight = 7.0;

// How long should it take the camera to focus on the target on the XZ plane
var xzSmoothLag = 0.3;

// How long should it take the camera to focus on the target vertically
var heightSmoothLag = 0.3;


private var _target : Transform;
private var _controller : ThirdPersonController;

private var _centerOffset = Vector3.zero;
private var _headOffset = Vector3.zero;
private var _footOffset = Vector3.zero;

private var _xzVelocity = 0.0;
private var _yVelocity  = 0.0;
private var _cameraHeightVelocity = 0.0;


// ===== UTILITY FUNCTIONS =====

// Apply the camera logic to the camera with respect for the target
function process()
{
    // Early out if we don't have a target
    if ( !_controller )
        return;

    var targetCenter = _target.position + _centerOffset;
    var targetHead   = _target.position + _headOffset;
    var targetFoot   = _target.position + _footOffset;

    // Determine the XZ offset of the focus position from the target foot
    var xzOffset = Vector2(focusPosition.x, focusPosition.z) - Vector2(targetFoot.x, targetFoot.z);

    // Determine the distance of the XZ offset
    var xzDistance = xzOffset.magnitude;

    // Determine the Y distance of the focus position from the target foot
    var yDistance = focusPosition.y - targetFoot.y;

    // Damp the XZ distance
    xzDistance = Mathf.SmoothDamp(xzDistance, 0.0, _xzVelocity, xzSmoothLag);

    // Damp the XZ offset
    xzOffset *= xzDistance;

    // Damp the Y distance
    yDistance = Mathf.SmoothDamp(yDistance, 0.0, _yVelocity, heightSmoothLag);

    // Reposition the focus position by the dampened distances
    focusPosition.x = targetFoot.x + xzOffset.x;
    focusPosition.y = targetFoot.y + yDistance;
    focusPosition.z = targetFoot.z + xzOffset.y;

    var minCameraHeight = targetHead.y;
    var targetCameraHeight = minCameraHeight + idleHeight;

    // Determine the current camera height with respect to the minimum camera height
    var currentCameraHeight = Mathf.Max(cameraTransform.position.y, minCameraHeight);

    // Damp the camera height
    currentCameraHeight = Mathf.SmoothDamp( currentCameraHeight, targetCameraHeight, _cameraHeightVelocity, heightSmoothLag );

    // Position the camera over the focus position
    cameraTransform.position = focusPosition;
    cameraTransform.position.y = currentCameraHeight;

// PROBLEM CODE - BEGIN

    // Have the camera look at the focus position
    cameraTransform.LookAt(focusPosition, Vector3.forward);

// PROBLEM CODE - END

    Debug.Log("Camera Focus Position: " + focusPosition);
    Debug.Log("Camera Transform Position: " + cameraTransform.position);
}

// ===== END UTILITY FUNCTIONS =====


// ===== UNITY FUNCTIONS =====

// Initialize the script
function Awake( )
{
    // If the camera transform is unassigned and we have a main camera, 
    //   set the camera transform to the main camera's transform
    if ( !cameraTransform && Camera.main )
        cameraTransform = Camera.main.transform;

    // If we don't have a camera transform, report an error
    if ( !cameraTransform )
    {
        Debug.Log( "Please assign a camera to the TopDownThirdPersonCamera script." );
        enabled = false;    
    }

    // Set the target to the game object transform
    _target = transform;

    // If we have a target set the controller to the target's third person controller
    if ( _target )
    {
        _controller = _target.GetComponent( ThirdPersonController );
    }

    // If we have a controller, calculate the center offset and head offset
    if ( _controller )
    {
        var characterController : CharacterController = _target.collider;
        _centerOffset = characterController.bounds.center - _target.position;
        _headOffset = _centerOffset;
        _headOffset.y = characterController.bounds.max.y - _target.position.y;
        _footOffset = _centerOffset;
        _footOffset.y = characterController.bounds.min.y - _target.position.y;
    }
    // If we don't have a controller, report an error
    else
        Debug.Log( "Please assign a target to the camera that has a ThirdPersonController script attached." );

    // Apply the camera logic to the camera
    process();
}

function LateUpdate( )
{
    // Apply the camera logic to the camera
    process();
}

// ===== END UNITY FUNCTIONS =====

我已经用问题代码注释标记了问题代码部分。如果问题代码被删除，它允许WASD移动再次工作，但是相机不再盯着目标。

对这个问题的任何见解都是非常感谢的。

Answer 1

我想出了问题，问题在于我正在使用的ThirdPersonController.js脚本。在函数UpdateSmoothedMovementDirection()中，ThirdPersonController使用cameraTransform根据摄像机所观察的位置确定XZ平面的前进方向。在此过程中，它将Y轴归零，并将剩下的归零。

我在自定义的cameraTransform.LookAt脚本中执行的TopDownCamera.js ()调用让摄像机直接向下看Y轴。因此，当ThirdPersonController抓住它并将Y轴归零时，我最终得到的方向为零，这导致XZ运动无处可去。

复制ThirdPersonController.js并修改代码，以便：

var forward = cameraTransform.TransformDirection(Vector3.forward);
forward.y = 0;
forward = forward.normalized;

变成：

forward = Vector3.forward;

解决了这个问题。