防止相机围绕相对 z 轴旋转答案

【问题标题】：Keep camera from rotating around relative z-axis防止相机围绕相对 z 轴旋转
【发布时间】：2021-10-25 09:12:57
【问题描述】：

我正在尝试创建模仿统一场景编辑器行为的相机移动，您可以在其中通过 2d 鼠标移动围绕场景执行球形旋转。到目前为止，在给定 x 或 y 移动的情况下，相机正在正确旋转，但是对角拖动会导致相机围绕其相对 z 轴旋转，直到它被锁定。我不能强迫相机相对于世界向上看原点，因为那样它就不能倒置旋转

这是我附加到相机的脚本

using UnityEngine;

public class MainCamera : MonoBehaviour
{
    Vector2 startingPosition;
    Vector2 mousePosition;
    Vector3 orthogonalCameraVector;
    float degreesPerUnitWidth = 180f / Screen.width;
    float degreesPerUnitHeight = 180f / Screen.height;
    float cameraRadius = 10;

    void Start()
    {
        transform.position = new Vector3(0, 0, -cameraRadius);
        transform.LookAt(Vector3.zero);
        orthogonalCameraVector = -Vector3.left;
    }

    void LateUpdate()
    {
        if (Input.GetMouseButtonDown(0))
        {
            mousePosition = Input.mousePosition;
        }

        if (Input.GetMouseButton(0))
        {
            var input = new Vector2(Input.mousePosition.x ,Input.mousePosition.y);

            startingPosition = mousePosition;
            var mouseDelta = startingPosition - input;

            var xzDegrees = -mouseDelta.y * degreesPerUnitHeight;
            var xzRotation = Quaternion.AngleAxis(xzDegrees, orthogonalCameraVector); // rotate about the relative x-z plane
            var yRotation = Quaternion.AngleAxis(-mouseDelta.x * degreesPerUnitWidth, Vector3.up); // rotate about the world y-axis
            var rotation = xzRotation * yRotation;
            orthogonalCameraVector = rotation * orthogonalCameraVector;
            transform.position = rotation * transform.position;
            transform.rotation = rotation * transform.rotation;
            mousePosition = Input.mousePosition;
        }
    }
}

【问题讨论】：

标签： unity3d

【解决方案1】：

我意识到orthogonalCamerVector 只需要围绕 y 轴旋转，因为我想保持它与 xz 平面平行。然后，我在旋转transform 之前将此旋转应用于orthogonalCamerVector，因此它始终围绕固定平面旋转，因此它看起来像这样：

        var xzDegrees = -mouseDelta.y * degreesPerUnitHeight;
        var yRotation = Quaternion.AngleAxis(-mouseDelta.x * degreesPerUnitWidth, Vector3.up); // rotate about the world y-axis
        orthogonalCameraVector = yRotation * orthogonalCameraVector;
        var xzRotation = Quaternion.AngleAxis(xzDegrees, orthogonalCameraVector); // rotate about the relative x-z plane
        var rotation = xzRotation * yRotation;
        transform.position = rotation * transform.position;
        transform.rotation = rotation * transform.rotation;

【讨论】：