Vector cross product

Vector cross product a ^ b

High school mathematics, we can get a formula a * b = | a | * | b | * sin <a, b>

You can be acquired using cross product of two vectors of the left and right positions, as shown in FIG.

One case (case y will be removed after a top view corresponding to the coordinate system x, z):

    Vector3 a = new Vector3 (1,0,2);

    Vector3 b = new Vector3 (2,0,1);

    Vector3 c = new Vector3 (2,0,-1);

    Vector3 d = new Vector3 (-2,0,-1);


    // Use this for initialization
    void Start () {

        Debug.LogError(Vector3.Angle(a,b));//36.8699

        Debug.LogError(Vector3.Cross(a,b).y);//3
        Debug.LogError(Vector3.Cross(b,d).y);//0
        Debug.LogError(Vector3.Cross(a,c).y);//5
        Debug.LogError(Vector3.Cross(a,d).y);//-3

    }

The above code we can see ∠aob = 36.8699 °
The dot product equation: a * Vector vector b = | a | * | b | * sin36.8699 ° = 5 * Root Root 5 * sin36.8699 ° = 3;

Sin curve is known, we can calculate the position of the cross product vector. Note that two opposite vector dot product at this time if the result is 0 is the agent.

Summary, Vector3.Cross (a, b) .y> 0 in the a-b represents the left, and vice versa in a right of b.