我尝试在Unity中实现一个简单的叉车。向左、向右、向上和向下移动都很好：Box stays in place
同时向左/右和上/下移动（箱子对角移动），箱子从货叉上滑落：Box is sliding off
有人有什么想法吗？
我已经试过了

• 当拾取箱子时，使其成为叉车的子件
• 为货叉和货箱添加具有高摩擦力的Physics Material 2D
• 将箱子的x速度设置为叉车的x速度
• 降低叉车的移动和提升速度
• 减少项目设置中的固定时间临时值
• 增加盒子的质量和重力比例

叉车和货箱都有一个附加了Body Type Dynamic和Collision Detection Continuous的刚体2D。
目前我正在移动叉车，代码如下：

private void FixedUpdate()
    {
        //Moving Left/Right
        if (moveRight)
        {
            timeElapsedDeceleration = 0;
            rb.velocity = new Vector2(Mathf.Lerp(rb.velocity.x, drivingSpeed, timeElapsedAcceleration / 2), rb.velocity.y);
            timeElapsedAcceleration += Time.fixedDeltaTime;
        }
        else if (moveLeft)
        {
            timeElapsedDeceleration = 0;
            rb.velocity = new Vector2(Mathf.Lerp(rb.velocity.x, -drivingSpeed, timeElapsedAcceleration / 2), rb.velocity.y);
            timeElapsedAcceleration += Time.fixedDeltaTime;
        }
        else
        {
            timeElapsedAcceleration = 0;
            rb.velocity = new Vector2(Mathf.Lerp(rb.velocity.x, 0, timeElapsedDeceleration / 2), rb.velocity.y);
            timeElapsedDeceleration += Time.fixedDeltaTime;
        }

        //Lifting
        if (moveForksUp && forks.transform.localPosition.y <= maxLiftHeight)
        {
            forks.transform.localPosition = new Vector2(forks.transform.localPosition.x, forks.transform.localPosition.y + liftingSpeed * Time.fixedDeltaTime);
            liftableMast.transform.localPosition = new Vector2(liftableMast.transform.localPosition.x, liftableMast.transform.localPosition.y + liftingSpeed / 1.5f * Time.fixedDeltaTime);
        }
        else if (moveForksDown && forks.transform.localPosition.y >= minLiftHeight)
        {
            forks.transform.localPosition = new Vector2(forks.transform.localPosition.x, forks.transform.localPosition.y - liftingSpeed * Time.fixedDeltaTime);
            liftableMast.transform.localPosition = new Vector2(liftableMast.transform.localPosition.x, liftableMast.transform.localPosition.y - liftingSpeed / 1.5f * Time.fixedDeltaTime);
        }
    }

在向左和向上同时移动时， Package 盒不应滑落。