Explain several mobile ways of unity in detail

Preface

Recently, I am learning how to make FPS game , Learned how to use the character controller to control the movement and jumping of the character, and so on , Combine what you learned before transform, Rigid bodies, etc. make objects move , Different mobile modes are suitable for different scenes , Today, let's take a brief inventory of various mobile modes and their advantages and disadvantages , If there is something wrong , Your advice are most welcome .

Front row reminders ： This article only represents personal views , For exchange and learning , If you have different opinions, please comment , The author must study hard , Day day up .

Video Explanation ：
Detailed explanation Unity Several mobile ways of _BiLiBiLi

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One 、 Use Transform Components

Unity Each game object in the scene has a Transform Components , The location used to store the object 、 rotate 、 Basic attributes such as scaling , The principle of this way is through Update Function updates its position every frame to achieve the purpose of moving .

1. Transform.position

The most basic way to move , Every frame += Calculated new location , More intuitive

    public float speed = 3.0f;
    void Update()
    {
        transform.position += new Vector3(0, 0, speed * Time.deltaTime);
    }

2. Transform.Translate

How much distance does it move in a certain direction per second , This method is not much different from the previous one , But when coordinate transformation is needed , Using this method, the conversion step can be omitted .
translate(V3 vector , Coordinate system ( Leave blank and default to Space.Self));

    public float speed = 3.0f;
    void Update()
    {
        transform.Translate(Vector3.forward * Time.deltaTime * speed);
    }

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Two 、 Use Vector3 The interpolation method of

Vector3 Type can store the location of objects 、 Direction . Aforementioned transform The basic information of the component is provided by Vector3 Type stored , So you can V3 The self-contained class method obtains relatively smooth parameters through some operations on the position , The essence of its movement is to modify the object position. It depends on the situation and needs V3 Of 4 An interpolation method .Mathf There are also these methods in the class , But the argument is float, The way to use it is roughly the same , If readers are interested , Learn by yourself .

1. Vector3.Lerp

The linear difference between two vectors , Applicable to moving from a certain point to a certain point （ Or follow something ）, Slow motion
Here the linear movement is controlled by the time parameter , If written as Speed*Time.deltaTime Theoretically, it will never arrive , But how to use... Is not discussed here Lerp Uniform speed has been achieved , Write later .
Lerp( The current position (V3), Target location (V3), Time (float)) The less time , The slower the slow effect

    public Transform target; // The object being followed 
    public float speed = 3.0f;
    void Update()
    {
        Vector3 lerp =  Vector3.Lerp(transform.position, target.position, Time.deltaTime * speed);
        transform.position = lerp;
    }

2. Vector3.Slerp

The sphere between two vectors （ Arc ） Difference value , Applicable to moving from a certain point to a certain point （ Or follow something ）, Slow motion , The farther away the current position is from the target position , The more obvious the effect
Slerp( The current position (V3), Target location (V3), Time (float)) The less time , The slower the slow effect

    public Transform target; // The object being followed 
    public float speed = 3.0f;
    void Update()
    {
        Vector3 slerp =  Vector3.Slerp(transform.position, target.position, Time.deltaTime * speed);
        transform.position = slerp;
    }

3. Vector3.MoveTowards

and Lerp The functions are basically the same , But this function has a maximum speed limit , And is uniform Move towards the target , and Lerp and Slerp It will slow down when reaching the position （ Slow down ）
MoveTowards( The current position (V3), Target location (V3), Maximum speed (float))
Speed parameters ： Take a positive target and approach , Take negative and stay away from the target

    public Transform target; // The object being followed 
    public float speed = 1.0f;
    void Update()
    {
        Vector3 movetowards =  Vector3.MoveTowards(transform.position, target.position, Time.deltaTime * speed);
        transform.position = movetowards;
    }

4. Vector3.SmoothDamp

The official translation is ：“ Smooth damping ”, Extremely silky from A Move to B spot , The speed is controllable , It is more suitable for camera following ,Lerp It is also suitable for camera following , The difference between the two is
SmoothDamp( The current position (V3), Target location (V3), Current speed (ref:V3), Time required (float), Maximum speed (float, Optional ),Time.deltaTime( Default )( Optional ))
Current speed ： The initial assignment is 0, This parameter is automatically modified every time the method is called , Note that it is set as a global variable , And for ref
Time required ： The smaller the value , The sooner we reach our goal

    public Transform target; // The object being followed 
    public Vector3 currentVelocity = Vector3.zero; // Current speed 
    public float smoothTime = 0.3f; // Time required 
    void Update()
    {
        Vector3 smoothdamp = Vector3.SmoothDamp(transform.position, target.position, ref currentVelocity, smoothTime);
        transform.position = smoothdamp;
    }

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3、 ... and 、 Use rigid bodies （Rigidbody） Components

Rigidbody Components control the position of an object through physical simulation , When using this component to control the movement of objects , Should be in FixedUpdate Update data in function , This method will be called before each physical simulation , This is better than Update Functions are more precise , The specific reason will be discussed later or you can search by yourself .

1. AddForce

Add a force in one direction to the rigid body , The rigid body will begin to move , This method is suitable for simulating rigid body motion under external force , Like a bullet . But pay attention to , This force is cumulative , It is not suitable to repeatedly apply force to simulate objects ！
AddForce( Directional force (V3), The mode of force (ForceMode, Default ：ForceMode.Force))

ForceMode( The mode of force ):
Force( Sustainable force , Affected by quality )
Acceleration( Sustainable acceleration , Not affected by quality )
Impulse( An instant impact , Affected by quality )
VelocityChange( An instantaneous speed change , Not affected by quality )
The author is a little confused about the differences between these things , Let's realize it by ourselves , The example shows the first force ,20 to Z Force

    public float forceNumber = 20f;
    public Rigidbody rig; // Get the rigid body component of the current object 
    void FixedUpdate()
    {
        Vector3 force = new Vector3(0, 0, forceNumber);
        rig.AddForce(force, ForceMode.Force);
    }

2. MovePosition

Move the rigid body to a new position , While moving, it is affected by physical simulation
MovePosition( New location (V3))

    public Vector3 speed = new Vector3(0, 0, 1);
    public Rigidbody rig; // Get the rigid body component of the current object 
    void FixedUpdate()
    {
        rig.MovePosition(transform.position + speed * Time.deltaTime);
    }

3. Velocity

Instantly give an object a constant speed , Lift the object to this speed , keep . Comparison AddForce More suitable for jumping function . Every jump is a constant height , If you jump , Figure 2 remember to set zero after each jump .

    public Vector3 high = new Vector3(0, 0, 10);
    public Rigidbody rig; // Get the rigid body component of the current object 
    private void FixedUpdate() {
        rig.velocity += high * Time.deltaTime;
    }

    public Vector3 high = new Vector3(0, 10, 0);
    public Rigidbody rig; // Get the rigid body component of the current object 
    private void Update() {
        if(Input.GetKeyDown(KeyCode.J))
        {
            rig.velocity = high;
        }
    }

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Four 、 Use character controllers （Character Controller） Components

As the name suggests , yes Unity A component launched specifically for character mobility , Objects using character controllers have the effect of rigid bodies , But it won't roll （ It means that the motion is only limited by the collision body , Not affected by other factors ）, Very suitable for character movement . You can also set slope parameters , A certain slope automatically lifts , It is also a collision body , The specific details will not be repeated in this chapter .

1. SimpleMove

Move the character at a certain speed , In seconds , There is no need to multiply by time , With gravity
SimpleMove( Directional force (V3))

    public float speed = 5;
    public CharacterController cc; // Get the rigid body component of the current object 
    void Update() {
        cc.SimpleMove(transform.forward * speed);
    }

2. Move

Move the character at a certain speed , There is no gravity , You need to calculate the whereabouts by yourself
Move( Directional force (V3))

    public float speed = 5;
    public CharacterController cc; // Get the rigid body component of the current object 
    void Update() {
        cc.Move(transform.forward * speed * Time.deltaTime);
    }

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5、 ... and 、 Summary and references

1. summary

Simply distinguish the above ways , It can be divided into physical movement and non physical movement , Readers should distinguish which objects should be used in which way .

• For example, non physical movement is applied to the movement obstacles in the level , Because there is no need for relevant obstacles to perform physical operations .
• For example, the camera follows the character , In a simple way, it can be directly used as a sub object of the character or directly calculate the offset , Directly added to the camera position, But too blunt , So consider joining Lerp or SmoothDamp, Make the camera follow more smoothly .
• For example, character movement , If non physical methods are used , Cannot interact with the environment , If rigid body components are used , Collision and toppling may occur , It will generate forces in many directions , It's complicated to deal with , So consider using character controllers , Restrict the movement of objects only in case of collision , It won't lead to many strange things .
• about V3 Application of interpolation function , It can handle some motion conversion more smoothly , The specific usage should be expanded by readers .

There are many things I haven't clarified in this article , It will be revised after being straightened out in the future , If readers have some different views on some of the fragments , Please leave a message to discuss .

2. Reference material

1.https://blog.csdn.net/jiumengdz/article/details/78537758
2.https://www.cnblogs.com/claireyuancy/p/7266586.html
3.https://www.sohu.com/a/211459755_667928
4.https://www.cnblogs.com/CasualAttachment/p/7308993.html
5.https://blog.csdn.net/six_sex/article/details/51114083
6.https://blog.csdn.net/renkai0406/article/details/63800248
7.https://blog.csdn.net/weixin_44370124/article/details/90080871