Basic syntax of unity script (1) - common operations of game objects

Common operations of game objects

Unity Many operations on game objects in use scripts to modify objects Transform( Transform attributes ) And Rigidbody( Rigid body properties ) Parameter to achieve .

The object rotates

adopt Transform

Transform.Rotate()

  private void Update()
    {
    
        this.transform.Rotate(90, 0, 0);// Around the x Shaft rotation 90 degree . A positive value means clockwise , A negative value means counterclockwise 
    }

Pay attention to such utilization transform To realize the movement of objects , Generally, the overload with the fourth parameter is used to determine the axis of the transformation ,
Space.World: Rotate relative to the world coordinate system
Space.Self: Rotate relative to its own axis

adopt Rigidbody

Rigidbody.MoveRotation

Format

public void MoveRotation(Quaternion rot);

Quaternion： Quaternion angle

describe ： Rotate the rigid body to rotation.

Use Rigidbody.MoveRotation Rotate the rigid body , Conform to the interpolation settings of the rigid body .

If in Rigidbody It's on Rigidbody interpolation , Call Rigidbody.MoveRotation Will result in a smooth transition between the two rotations in any intermediate frame of the rendering . If you want to be in each FixedUpdate Continuous rotation of rigid bodies in , Use this option .

 Rigidbody m_Rigidbody;
 Vector3 m_EulerAngleVelocity;

    void Start()
    {
    
 
        m_Rigidbody = GetComponent<Rigidbody>();
        m_EulerAngleVelocity = new Vector3(0, 100, 0);
    }

    void FixedUpdate()
    {
    
        Quaternion deltaRotation = Quaternion.Euler(m_EulerAngleVelocity * Time.fixedDeltaTime);
        m_Rigidbody.MoveRotation(m_Rigidbody.rotation * deltaRotation);
    }

Objects move

The first way is through Velocity

But in most cases , The speed should not be modified directly , Because this may lead to unrealistic behavior , To set the speed of an object in each physical step .
A typical use is to change the speed when jumping in a first person shooter game , Because you want to change the speed immediately .

    Rigidbody rig;
    private void Update()
    {
    
        rig = this.gameObject.GetComponent<Rigidbody>();
        rig.velocity = new Vector3(0, 0, 5);// Every frame y Axial movement 5 A unit of 
    }

The second way is through UnityAPI——Rigidbody.MovePosition Mobile location

describe ： take kinematics The rigid body moves towards postion

Rigidbody.MovePosition Move the rigid body and conform to the interpolation settings . When rigid body interpolation is enabled ,Rigidbody.MovePosition Creates a smooth transition between frames .Unity Move a rigid body in each call . Occurs in world space FixedUpdate. Rigid body position Transfer from one location to another using Rigidbody.position instead of MovePosition.

public class NewBehaviourScript : MonoBehaviour // Declaration class 
{
    
    Rigidbody rig;
    public float speed = 5f;
    private void Start()
    {
    
        rig = this.gameObject.GetComponent<Rigidbody>();
    }
    private void FixedUpdate()
    {
    
        Vector3 input = new Vector3(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical"));
        rig.MovePosition(transform.position + input * Time.deltaTime * speed);// Move from current location to new location , Per second 5 Unit speed 
    }
}

The third way Rigidbody.AddForce( The most common way )

Format

public void AddForce ( Vector3 force , ForceMode mode = ForceMode.Force);

describe ： Add a force to the rigid body

Force edge force The vector direction is applied continuously . Appoint ForceMode mode It is allowed to change the type of force to Acceleration、Impulse or Velocity Change.

ForceMode.Force： Interpret input as force
ForceMode.Acceleration： Interpret the parameter as acceleration
ForceMode.Impulse： Interpret the parameters as pulses
ForceMode.VelocityChange： Interpret the parameter as a direct change in velocity （ In meters / Seconds per unit ）, And change the speed by the value of the force .

Forces can only be applied to active rigid bodies . If GameObject Inactive , be AddForce Invalid . Besides , Rigid bodies cannot be kinematic .

By default , Once the force is applied , The state of the rigid body is set to wake up , Unless the force is Vector3.zero.

   Rigidbody rig;
    public float force = 50f;
    private void Start()
    {
    
        rig = this.gameObject.GetComponent<Rigidbody>();
    }
    private void FixedUpdate()
    {
    
        if (Input.GetButton("Jump"))
        {
    
            rig.AddForce(transform.up * force);// Add a... Up 50 The power of the cow 
        }
    }

adopt Transform

The first way adopt Transform.Position

 private void Update()
    {
    
        transform.position = new Vector3(0, 0, 10);// towards z Axis movement 10 A unit of 
    }

The second way adopt UnityAPI——Transform.Translate

    private void Update()
    {
    
        transform.Translate(0, 0, 5,Space.Self);// Each frame of the object is oriented to z Axial movement 5 A unit of .
    }

Be careful

If a game object has a rigid body, you need to use the moving components of the rigid body .
At the same time, every frame of the rigid body calls the method to use FixedUpdate