问题描述

计算Unity场景中物体B在物体A坐标系下的坐标，且两物体没有父子关系

实现方法

计算一个物体A的position相对于另一个物体B（origin）的坐标

private Vector3 GetRelativePosition(Transform origin, Vector3 position)
{
    Vector3 distance = position - origin.position;
    Vector3 relativePosition = Vector3.zero;
    relativePosition.x = Vector3.Dot(distance, origin.right.normalized);
    relativePosition.y = Vector3.Dot(distance, origin.up.normalized);
    relativePosition.z = Vector3.Dot(distance, origin.forward.normalized);
    return relativePosition;
}

实现原理

计算物体A在物体B下的坐标，即将物体B的坐标origin视为坐标原点，物体A的坐标即为（B-A）*B的归一化方向。

参考链接

https://www.it610.com/article/1293777356627976192.htm