视频效果：

代码:

    /// <summary>/// 投影在扇形区域内的点/// </summary>/// <param name="targetPos">目标点</param>/// <param name="fanRadius">扇形半径</param>/// <param name="fanAngle">扇形圆心角</param>/// <param name="fanShape">扇形(扇形圆心)</param>/// <returns></returns>private Vector3 GetPosToFanProjection(Vector3 targetPos,float fanRadius,float fanAngle,Transform fanShape){Vector3 leftdir = Quaternion.AngleAxis(-fanAngle/2, fanShape.transform.up)*fanShape.transform.forward;Vector3 rightdir = Quaternion.AngleAxis(fanAngle/2, fanShape.transform.up)*fanShape.transform.forward;Vector3 leftP = fanShape.transform.position + leftdir * fanRadius;Vector3 rightP = fanShape.transform.position + rightdir * fanRadius;float dis = (targetPos - fanShape.transform.position).magnitude;float angle = Vector3.SignedAngle(fanShape.transform.forward, targetPos - fanShape.transform.position,fanShape.transform.up);if (dis > fanRadius){if (Mathf.Abs(angle) < 0.5f * fanAngle){return fanShape.transform.position + (targetPos - fanShape.transform.position).normalized * this.fanRadius;}else{//右顶点if (angle > 0){return rightP;}//左顶点else{return leftP;}}}else{if (Mathf.Abs(angle) < 0.5f * fanAngle){return targetPos;}else{//右边界if (angle > 0){return fanShape.transform.position + rightdir * dis;}//左边界else{return fanShape.transform.position + leftdir * dis;}}}}