BallControlScript.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.XR.ARFoundation;

/// <summary>
/// Controls the basketball.
/// </summary>
[RequireComponent(typeof(Rigidbody))]
public class BallControl : MonoBehaviour
{
    /// <summary>
    /// The force with which the ball is thrown
    /// </summary>
    public float m_ThrowForce = 100f;

    /// <summary>
    /// The x axis multiplier for the throwing force
    /// </summary>
    public float m_ThrowDirectionMultiplierX = 0.17f;

    /// <summary>
    /// The y axis multiplier for the throwing force
    /// </summary>
    public float m_ThrowDirectionMultiplierY = 0.67f;

    /// <summary>
    /// Distace Between Ball and Camera
    /// </summary>
    public Vector3 m_BallCameraOffset = new Vector3(0f, -1.6f, 2);

    /// <summary>
    /// The following variables contain the state 
    /// of the current throw of the ball.
    /// </summary>
    private Vector3 startPos;
    private Vector3 swishDirection;
    private float startTime = 0.0f;
    private float endTime = 0.0f;
    private float swishDuration = 0.0f;
    private bool directionChosen = false;
    private bool clickStarted = false;

    [SerializeField]
    GameObject ARCam;
    [SerializeField]
    ARSessionOrigin m_SessionOrigin;

    Rigidbody rb;

    void Start()
    {
        rb = gameObject.GetComponent<Rigidbody>();
        m_SessionOrigin = GameObject.Find("AR Session Origin").GetComponent<ARSessionOrigin>();
        ARCam = m_SessionOrigin.transform.Find("AR Camera").gameObject;
        ResetBallPosition();
    }

    void Update()
    {
        ThrowControls();

        // reset ball position in front of camera 5 seconds after we've thrown it.
        if (Time.time - endTime >= 5 && Time.time - endTime <= 6)
            ResetBallPosition();
        
    }

    /// <summary>
    /// Control the ball using mouse clicks.
    /// </summary>
    void ThrowControls()
    {
        // when we click / touch for the first time
        if (Input.GetMouseButtonDown(0))
        {
            startPos = Input.mousePosition;
            startTime = Time.time;
            clickStarted = true;
            Debug.Log("Click Started");

            directionChosen = false;
        }
        // when we release the click / touch
        else if (Input.GetMouseButtonUp(0))
        {
            endTime = Time.time;
            swishDuration = endTime - startTime;
            swishDirection = Input.mousePosition - startPos;
            Debug.Log("Click Ended");

            directionChosen = true;
        }
        // once we chose the direction, make ball follow that direction
        if (directionChosen)
        {
            rb.mass = 1;
            rb.useGravity = true;

            rb.AddForce(
                ARCam.transform.forward * m_ThrowForce / swishDuration + 
                ARCam.transform.up * swishDirection.y * m_ThrowDirectionMultiplierY + 
                ARCam.transform.right * swishDirection.x * m_ThrowDirectionMultiplierX);

            clickStarted = false;
            directionChosen = false;
            startTime = 0.0f;
            swishDuration = 0.0f;
            startPos = new Vector3(0, 0, 0);
            swishDirection = new Vector3(0, 0, 0);
        }
    }

    /// <summary>
    /// Reset ball's position
    /// </summary>
    void ResetBallPosition()
    {
        // change the rigidbody's properties such that the ball doesn't move until we throw it
        rb.mass = 0;
        rb.useGravity = false;
        rb.velocity = Vector3.zero;
        rb.angularVelocity = Vector3.zero;
        endTime = 0.0f;

        // position ball right in front of AR Camera
        Vector3 ballPos = ARCam.transform.position + ARCam.transform.forward + ARCam.transform.up * -0.45f;
        transform.position = ballPos;
    }
}