Unity basic functions

Mathf：

//1.π-PI
print(Mathf.PI);
//2. Take the absolute value-Abs
print(Mathf.Abs(-10));
print(Mathf.Abs(-20));
print(Mathf.Abs (1));
//3. Round up - Ce il To In t
float f = 1.3f;
int i = (int)f;
print(i);
print(Mathf.CeilToInt(f));
print(Mathf .CeilToInt(1.00001f));
//4. Round down-FloorToInt
print(Mathf.FloorToInt(9.6f));
//5. Clamp function-clamp limit size
print(Mathf.Clamp(10, 11, 20 ));//10
print(Mathf.Clamp(22, 11, 20));//20
print(Mathf.Clamp(15, 11, 20));//15
//6. Get the maximum value - Max
print(Mathf.Max(10, 11, 20)); //Get the maximum number
//7. Get the minimum value - Min
print(Mathf.Pow(10, 2)); //10 to the 2nd power
//8 .n times of a number-Pow
print(Mathf.FloorToInt(9.6f));
//9. Rounding-RoundToInt
print(Mathf.RoundToInt(9.6f));
//10. Return the square root of a number-Sqrt
print (Mathf.Sqrt(4f));//2
//11. Determine whether a number is 2 raised to the nth power-IsPowerofTwo
print(Mathf.IsPowerOfTwo(9));//false
//12. Determine positive and negative numbers- Sign
print(Mathf.Sign(9.6f));//positive number returns 1

Trigonometric functions:

// Convert radians to angles
float rad = 1;
float anger = rad * Mathf.Rad2Deg;
print(anger);
// Convert angles to radians
anger = 1;
rad = anger * Mathf.Deg2Rad;
print(rad);

//Note: For trigonometric function-related functions in Mathf, the passed-in parameter requires a radian value
print(Mathf.Sin(30 * Mathf.Deg2Rad));
print(Mathf.Cos(60 * Mathf.Deg2Rad));

//Note: The result obtained by the inverse trigonometric function is the arc corresponding to the sine or cosine value
rad = Mathf.Asin(0.5f);
print(rad * Mathf.Rad2Deg);
rad = Mathf.Acos(0.5f);
print(rad * Mathf.Rad2Deg);

Coordinate system conversion:

//World coordinate system
//Currently learned information related to the world coordinate system
//this.transform.position;
//this.transform.rotation;
//this.transform.eulerAngles;
//this.transform.lossyScale;
// Modifying them will result in changes to the relative world coordinate system

//Relative coordinate system
//The position of the object coordinate system relative to the parent object. Local coordinates. Relative coordinates
//this.transform.localPosition;
//this.transform.localEulerAngles;
//this.transform.localRotation;
//this.transform. localscale;
//Modifying them will result in changes in the object coordinate system relative to the parent object

//Three screen coordinate system
//Input.mouse Position
//screen.width;
//screen.height;

//Coordinate transformation related
//World to local
//this.transform.InverseTransformDirection
//this.transform.InverseTransformPoint
//this.transform.InverseTransformVector
//Local to world
//this.transform.TransformDirection
//this.transform.TransformPoint
//this.transform.TransformVector
//World to screen
//Camera.main.WorldToscreenPoint
//Screen to world
//Camera.main.ScreenToworldPoint;

//World to viewport
//Camera.main.WorldToViewportPoint
//Viewport to world
//Camera.main.ViewportToworldPoint
//Viewport to screen
//Camera.main.ViewportToScreenPoint
//Screen to viewport
//Camera.main .ScreenToViewportPoint;

vector:

//知识点一向量
        //三维向量-Vector3
        //Vector3有两种几何意义
        //1.位置一代表一个点
        print(this.transform.position);
        //2.方向一代表一个方向
        print(this.transform.forward);
        print(this.transform.up);

        //知识点二两点决定一向量
        //A和B此时几何意义是两个点
        Vector3 A = new Vector3(1, 2, 3);
        Vector3 B = new Vector3(5, 1, 5);
        //求向量
        //此时AB和BA他们的几何意义是两个向量
        Vector3 AB = B - A;
        Vector3 BA = A - B;

        //知识点三零向量和负向量
        print(Vector3.zero);
        print(Vector3.forward);
        print(Vector3.forward);

        //知识点四向量的模长
        //Vector3中提供了获取向量模长的成员属性
        //magnitude
        print(AB.magnitude);
        Vector3 c = new Vector3(5, 6, 7);
        print(c.magnitude);

        //知识点五单位向量
        print(AB.normalized);

        //向量加法
        //this.transform.position += new Vector3(1, 2, 3);
        this.transform.Translate(Vector3.forward * 5);      
        //向量减法
        //this.transform.position -= new Vector3(1, 2, 3);
        this.transform.Translate(-Vector3.forward * 5);
        //向量乘除标量
        this.transform.localScale *= 2;
        this.transform.localScale /= 2;

        //补充知识调试画线
        //画线段
        //前两个参数分别是起点终点
        Debug.DrawLine(this.transform.position, this.transform.position + this.transform.forward, Color.red);
        //画射线
        // 前两个参数分别是起点方向
        Debug.DrawRay(this.transform.position,transform.right, Color.green);

        //通过点乘判断对象方位
        //Vector3提供了计算点乘的方法
        Debug.DrawRay(this.transform.position, this.transform.forward, Color.red);
        //得到两个向量的点乘结果
        //向量a点乘AB的结果
        float dotResult = Vector3.Dot(this.transform.forward, target.position - this.transform.position);
        if (dotResult >= 0)
            print("它在我前方");
        else
            print("它在我后方");

//通过点乘推导公式算出夹角
        //步骤
        //1.用单位向量算出点乘结果
        //dot Result = Vector3.Dot(this.transform.forward, (target.position - this.transform.position).normalized);
        //2.用反三角函数得出角度
        print("角度" + Mathf.Acos(dotResult) * Mathf.Rad2Deg);
        //Vector3中提供了得到两个向量之间夹角的方法
        print("角度2" + Vector3.Angle(this.transform.forward, target.position - this.transform.position));

//叉乘计算
        print(Vector3.Cross(AA.position, BB.position));
        //叉乘几何意义
        //假设向量A和B都在X Z平面上
        //向量A叉乘向量B
        //y大于0证明B在A右侧
        //y小于0证明B在A左侧
        Vector3 vec = Vector3.Cross(BB.position, AA.position);
        if (vec.y > 0)
            print("AA在BB的右侧");
        else
            print("AA在BB的左侧");