Question

这是我的跳转代码，它在 void Update 中更新

 void Jump()
{
 if(isgrounded == true)
 {
 amountofjumps = jumps;    
 }
 if(Input.GetKeyDown(KeyCode.UpArrow) && amountofjumps > 0)
 {
 rb2d.velocity = Vector2.up * jump * Time.deltaTime;
 amountofjumps--;
 }
 else if(Input.GetKeyDown(KeyCode.UpArrow) && amountofjumps == 0 && isgrounded == true)
 {
 rb2d.velocity = Vector2.up * jump * Time.deltaTime;    
 }
 
}

这是我用于跳转代码的变量

bool isgrounded;
public float groundcheckradius;
public LayerMask whatisground;
public float jump;
private int amountofjumps;
public int jumps;

这是我检测地面的方法

 void checkforground()
{ 
isgrounded = Physics2D.Raycast(transform.position,Vector2.down, groundcheckradius,whatisground);
   
}
void OnDrawGizmos()
{
Gizmos.color = Color.red;
Gizmos.DrawLine(transform.position, transform.position + Vector3.down * groundcheckradius);  
}

提前致谢

Answer 1

Velocity 通常用于移动对象 try rigidbody2d.AddForce()。

void Jump()
{
    if (isgrounded == true)
    {
        amountofjumps = jumps;
    }
    if (Input.GetKeyDown(KeyCode.UpArrow) && amountofjumps > 0 && isgrounded == true)
    {
        rb2d.AddForce(transform.up * jump, ForceMode2D.Impulse);
        amountofjumps--;
    }
}

Answer 2

首先，设置 Time.deltaTime 时 velocity 没有意义。 velocity 已经与帧速率无关，因此当您将速度乘以 Time.deltaTime（对于 60 fps 大约为 0.017）时，它会变得非常小/慢。
其次，当前您会覆盖整个速度，因此如果您的玩家向前移动，它将完全停止 X 轴上的任何移动。
最后，当您接地时，您希望总是能够跳跃……不仅是在 amountofjumps == 0 的情况下，永远是这种情况因为就在您将其设置为 amountofjumps = jumps; 之前！从地面跳跃时，您根本不想检查 amountofjumps！

您可能更愿意使用例如

// get the current velocoty of the rigidbody
var velocity = rb2d.velocity;
// Only overwrite the Y velocity with the jump
velocity.y =  jump; 
// re-assign the changed vector to the rgidbody
rb2d.velocity = velocity;

然后我会将逻辑更改为例如

private void Jump()
{
    if(isgrounded)
    {
        amountofjumps = jumps; 
    
        // when you are grounded you can always jump!
        // Not only when the amountofjumps == 0
        // actually when you are grounded the amountofjumps shouldn't matter at all
        if(Input.GetKeyDown(KeyCode.UpArrow))
        {
            DoJump();
        }  
    }
    // As before while not grounded the amountofjumps is taken into account
    else if(amountofjumps > 0)
    {
        if(Input.GetKeyDown(KeyCode.UpArrow))
        {
            DoJump();
        }
    }
}

private void DoJump()
{
    // get the current velocoty of the rigidbody
    var velocity = rb2d.velocity;
    // Only overwrite the Y velocity with the jump
    velocity.y =  jump; 
    // re-assign the changed vector to the rgidbody
    rb2d.velocity = velocity;

    // Always reduce the amount of jumps also when jumping from the ground
    amountofjumps--;
}

玩家不会在 unity2d 中跳跃

2 个答案: