鼠标控制物体位移与旋转

using UnityEngine;

namespace GameMain
{
    public class ModelControl : MonoBehaviour
    {
        private bool _isMouseDown = false;
        private bool _isRightMouseDown = false;
        private Vector3 _startPos;
        private float _scrollValue;
        private Vector3 _modelToCameraDelta;
        private const float RotateSpeed = 15f;
        private const float MoveSpeed = 0.1f;


        [SerializeField] private Transform targetModel;
        [SerializeField] private Transform modelCamera;

        private void Update()
        {
            if (null == targetModel)
            {
                return;
            }

            if (Input.GetMouseButtonDown(0))
            {
                _startPos = Input.mousePosition;
                _isMouseDown = true;
            }

            if (Input.GetMouseButtonUp(0))
            {
                _isMouseDown = false;
            }

            if (Input.GetMouseButtonDown(1))
            {
                _startPos = Input.mousePosition;
                _isRightMouseDown = true;
            }

            if (Input.GetMouseButtonUp(1))
            {
                _isRightMouseDown = false;
            }
            
            _scrollValue = Input.GetAxis("Mouse ScrollWheel");
            if (_scrollValue == 0) return;
            _modelToCameraDelta = (modelCamera.position - targetModel.position).normalized;
            targetModel.Translate(_modelToCameraDelta * (_scrollValue * MoveSpeed * 1000 * Time.deltaTime),Space.World);
        }

        private void FixedUpdate()
        {
            if (_isMouseDown)
            {
                var currentPos = Input.mousePosition;
                var delta = currentPos - _startPos;
                var rotationAxis = Vector3.Cross(delta, Vector3.forward).normalized;
                var rotateAmount = delta.magnitude * RotateSpeed * Time.fixedDeltaTime;

                targetModel.Rotate(rotationAxis, rotateAmount, Space.World);
                _startPos = currentPos;
            }

            if (_isRightMouseDown)
            {
                var currentPos = Input.mousePosition;
                var delta = currentPos - _startPos;
                var moveAmount = delta * (MoveSpeed * Time.fixedDeltaTime);
                
                targetModel.position += moveAmount;
                _startPos = currentPos;
            }

        }
    }
}