Unity learning notes (rigid body physics collider trigger)

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1.Rigidbody- rigid body

1.Property

Property:	Function:
Mass	The mass of the object , default quality （ Company ）
Drag	The air resistance to the motion of an object
Angular Drag	Torque caused by air damping when the object rotates
Use Gravity	Whether it is affected by gravity
Is Kinematic	If it conforms to dynamics , Then the object is not affected by the physical engine , It can only be changed by adjustment , But it can still interact with other rigid bodies , Generally used for testing .

 [SerializeField] private float _forceAmount = 100f;
//[SerializeField] Serialize fields for , Private fields can be displayed in unity Debug the engine 

    private Rigidbody _rigidbody;
    // Start is called before the first frame update
    void Start()
    {
        _rigidbody = GetComponent<Rigidbody>();
    }
    // Update is called once per frame
    void Update()
    {
        if (Input.GetButtonDown("Fire1"))// Click the left mouse button once to execute 
        {
            _rigidbody.AddForce(Vector3.up * _forceAmount);
        }   
    }

2. Physical material

1.Property:

Property:	Function:
Dynamic Friction	Dynamic friction , The value is usually in 0~1 Between , by 0 Means smooth plane
Static Friction	Static friction , Usually in 0~1 Between
Bounciness	Elasticity index ,0~1,0 There is no elasticity ,1 It is completely elastic , No loss of energy
Friction Combine	How to calculate friction when two colliding bodies collide
- Average	Choose the average of the two
- Minimum	Choose the minimum of both
- Maximum	Choose the maximum of both
- Multiply	Choose to multiply the two
Bounce Combine	Equate to Friction Combine

2. The creation process

3. Collision

3.1 Edit Collider

You can modify the collider size , As long as you touch the collider, set the range , It will trigger OncollisionEnter() function

OncollisionEnter() The function is the function excited when the object collides .Material Physical material for collision body , You need to create and add by yourself .

private Renderer _renderer;
    void Awake()
    {
        // Get the component renderer object 
        _renderer = GetComponent<Renderer>();
    }
    private void OnCollisionEnter(Collision collision)
    {
        Color randomlySelectedColor=GetRandomColor();
        _renderer.material.color=randomlySelectedColor;
    }
 
    private Color GetRandomColor()
    {
        return new Color(
            r:UnityEngine.Random.Range(0f,1f),
            g:UnityEngine.Random.Range(0f,1f),
            b:UnityEngine.Random.Range(0f,1f));
    }

 private void OnCollisionEnter(Collision collision)
    {

        Debug.Log("Impacted at" +collision.contacts[0].point);
        float rayDrawDistance = 5f;
        Debug.DrawRay(
            collision.contacts[0].point,
            collision.contacts[0].normal*rayDrawDistance,// Normal direction of contact point 
            Color.red,
            1f);
    }

4. Trigger

OnTriggerEnter() The function is when the object triggers Trigger The post excitation function of the object .

    void Awake()
    {
        // Get the component renderer object 
        _renderer = GetComponent<Renderer>();
    }
private void OnTriggerEnter(Collider other)
    {
        Color randomlySelectedColor = GetRandomColorWithAlpha();
        _renderer.material.color = randomlySelectedColor;
    }
    private Color GetRandomColorWithAlpha()
    {
        return new Color(
            r: UnityEngine.Random.Range(0f, 1f),
            g: UnityEngine.Random.Range(0f, 1f),
            b: UnityEngine.Random.Range(0f, 1f),
            a:0.25f);
    }

The following figure shows the settings Trigger Changes after ,Trigger Objects do not affect the motion of other objects .