How to realize the real world physics?

Questions & Answers
1

For example, if i drag an object with mouse,when i throw it to the sky,the object will have a x-axis speed and a gravity,so the object will drop off very elegant and nice,but i can’t work it out.It make me very anxiety.Thanks anyway~

2

Do not worry, sit back, have a valium (if needed) and attach this script to the thrown object:

#pragma strict

/*  Mouse Throw Physics by save
    Attach this script to a GameObject you would like to throw
    Last modified 2012-03-12
*/

@script RequireComponent(Rigidbody)
@script RequireComponent(Collider)

var strength : int = 20;                    //The strength to multiply in AddForce
var AlterUseOfGravity : boolean = true;     //If useGravity is off and AlterUseOfGravity is off the object will continue to float

static var cam : Camera;
static var cameraTransform : Transform;

private var myTransform : Transform;
private var myRigidbody : Rigidbody;

private var myMagnitude : Vector3 = Vector3.zero;
private var initialPosition : Vector3;
private var setZdepth : float = .0;

private var activated : boolean = false;

function Awake () {
    if (cam==null || cameraTransform==null) {
        cam = Camera.main;
        cameraTransform = cam.transform;
    }
}

function Start () {
    myTransform = transform;
    myRigidbody = rigidbody;
    initialPosition = myTransform.position;
}

function Update () {
    if (activated) {
        SetPosition();
    }
}

function SetPosition () {
    if (!myRigidbody.isKinematic) {
        myRigidbody.isKinematic = true;
        if (AlterUseOfGravity) myRigidbody.useGravity = false;
        setZdepth = myTransform.position.z-cameraTransform.position.z;
    }

    var pos : Vector3;
    pos = Input.mousePosition;
    pos.x = Mathf.Clamp(pos.x, 0, Screen.width);
    pos.y = Mathf.Clamp(pos.y, 0, Screen.height);
    var newPos : Vector3 = Camera.main.ScreenToWorldPoint(Vector3(pos.x, pos.y, setZdepth));
    myTransform.position = newPos;  

    myMagnitude = (myTransform.position - initialPosition) /Time.deltaTime;

    initialPosition = myTransform.position;

    if (Input.GetMouseButtonUp(0)) {
        AddForce(myMagnitude);
    }

}

function OnMouseDown () {
    activated = true;
}

function AddForce (m : Vector3) {
    myRigidbody.isKinematic = false;
    if (AlterUseOfGravity) myRigidbody.useGravity = true;
    myRigidbody.AddForce(m*strength);
    activated = false;
}