Re-making a Classic in VR

Chris Zaharia

@chrisjz#SydVR

Project• Engine - Unity 3D (v4.5)• View + head tracking - Oculus Rift DK1• Hand tracking - Razer Hydra• C# Language• Re-create game up to first mission in

first world

To Do• Integrate Rift with player• Integrate Razer Hydra with player’s

hands• Player avatar• Player movement• Hand interaction with objects

Setup World• Start a new project• Create a scene• Import or create an environment• Create a Directional Light to light up the

environment

Create Player & Integrate Rift• Create a GameObject called Player• Attach the component Character Controller• Attach the scripts Character Motor and FPSInput

Controller• Attach OVRCameraController prefab as child of

Player GameObject• In script FPSInput Controller set “Ovr Camera”

variable as CameraRight• Drag OVRCameraController behind player

FPSInputController.csusing UnityEngine;using System.Collections;

// Require a character controller to be attached to the same game object[RequireComponent(typeof(CharacterMotor))][AddComponentMenu("Character/FPS Input Controller")]

public class FPSInputController : MonoBehaviour {public GameObject ovrCamera;

private CharacterMotor motor; private bool inputEnabled; // If input is enabled/disabled

// Use this for initializationvoid Awake (){

motor = GetComponent<CharacterMotor>();}

void Start() {inputEnabled = true;

}

FPSInputController.cs (2)// Update is called once per framevoid Update (){

// Get the input vector from keyboard or analog stickVector3 directionVector= new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));

motor.inputJump = Input.GetButton ("Jump");

// Play jumping audio clipsif (initialJumpAudioClips.Length > 0 && motor.inputJump && motor.grounded && !audio.isPlaying) {

audio.clip = initialJumpAudioClips[Random.Range(0, initialJumpAudioClips.Length)];audio.Play();

}

if (directionVector != Vector3.zero) {// Get the length of the directon vector and then normalize it// Dividing by the length is cheaper than normalizing when we already have the length anywayfloat directionLength= directionVector.magnitude;directionVector = directionVector / directionLength;

FPSInputController.cs (3)// Make sure the length is no bigger than 1directionLength = Mathf.Min(1, directionLength);

// Make the input vector more sensitive towards the extremes and less sensitive in the middle// This makes it easier to control slow speeds when using analog sticksdirectionLength = directionLength * directionLength;

// Multiply the normalized direction vector by the modified lengthdirectionVector = directionVector * directionLength;

}

// Apply the direction to the CharacterMotormotor.inputMoveDirection = ovrCamera.transform.rotation * directionVector;

}

public void SetInputEnabled (bool status) {inputEnabled = status;

}}

Attach avatar to player

• Place player 3D model as child of Player object and name it “Avatar”

• Move the OVR camera object behind the model

• Make the model’s head rotate with the Rift’s head tracker by moving the head model inside the CameraRight object

Hydra Integration for Hands• Import Sixense Unity plugin for Razer

integration• Create GameObject “Hands” as child of

OVRCameraController• Place SixenseInput prefab as child of

OVRCamera Controller

Hydra Integration for Hands• Create GameObjects “Left Hand” + “Right

Hand” as children of “Hands”• Place the player’s hand models within each

of those 2 hand objects respectively• Attach script SixenseHandController to each

hand GameObject• Set the “Hand” variable to either LEFT or

RIGHT, as appropriate

Control Player using Hydra• Modify FPSInputController script to map

Hydra’s left joystick and a button to moving and jumping

• Create PlayerLook script in project to handle looking in environment

• Create HydraLook script to map Hydra’s right joystick to looking, inheriting PlayerLook class in its script

FPSInputController.csvoid Start() {

IgnorePlayerColliders ();inputEnabled = true;

}

// Update is called once per framevoid Update (){

// Get the input vector from keyboard or analog stickVector3 directionVector= new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));

// Get the input vector from hydraSixenseInput.Controller hydraLeftController = SixenseInput.GetController (SixenseHands.LEFT);SixenseInput.Controller hydraRightController = SixenseInput.GetController (SixenseHands.RIGHT);

if (hydraLeftController != null) {directionVector= new Vector3(hydraLeftController.JoystickX, 0, hydraLeftController.JoystickY);

}

if (hydraRightController != null) {motor.inputJump = hydraRightController.GetButton (SixenseButtons.BUMPER);

} else {motor.inputJump = Input.GetButton ("Jump");

}

FPSInputController.cs (2)…

}

…

// Prevent colliders on player from colliding with each other i.e. hand colliders with body collidervoid IgnorePlayerColliders () {

Collider[] cols = GetComponentsInChildren<Collider>();

foreach (Collider col in cols) {if (col != collider) {

Physics.IgnoreCollision(col, collider);}

}}

}

PlayerLook.csusing UnityEngine;using System.Collections;

/// PlayerLook rotates the transform based on the input device's delta./// Minimum and Maximum values can be used to constrain the possible rotation.

/// Based on Unity's MouseLook script.

[AddComponentMenu("Camera-Control/Player Look")]public class PlayerLook : MonoBehaviour {

public enum RotationAxes { XAndY = 0, X = 1, Y = 2 }public RotationAxes axes = RotationAxes.XAndY;public float sensitivityX = 15F;public float sensitivityY = 15F;

public float minimumX = -360F;public float maximumX = 360F;

public float minimumY = -60F;public float maximumY = 60F;

protected float rotationY = 0F;

PlayerLook.cs (2)protected float axisX, axisY;

void Start () {// Make the rigid body not change rotationif (rigidbody)

rigidbody.freezeRotation = true;}

protected virtual void Update () {

if (axes == RotationAxes.XAndY){

float rotationX = transform.localEulerAngles.y + axisX * sensitivityX;

rotationY += axisY * sensitivityY;rotationY = Mathf.Clamp (rotationY, minimumY, maximumY);

transform.localEulerAngles = new Vector3(-rotationY, rotationX, 0);}else if (axes == RotationAxes.X){

transform.Rotate(0, axisX * sensitivityX, 0);}

PlayerLook.cs (3)else{

rotationY += axisY * sensitivityY;rotationY = Mathf.Clamp (rotationY, minimumY, maximumY);

transform.localEulerAngles = new Vector3(-rotationY, transform.localEulerAngles.y, 0);}

}}

HydraLook.csusing UnityEngine;using System.Collections;

public class HydraLook : PlayerLook {

protected override void Update () {// Get the input vector from hydraSixenseInput.Controller hydraRightController = SixenseInput.GetController (SixenseHands.RIGHT);

if (hydraRightController != null) {axisX = hydraRightController.JoystickX;axisY = hydraRightController.JoystickY;

}

base.Update ();}

}

Hand Interactions using Hydra• Attach invisible rectangles to each hand to use

as colliders for hands• Name the objects LeftHandCollider and

RightHandCollider respectively• Modify the SixenseHandController with

functions to grab objects and throw based on hand velocity

• Tag any grabbable objects with “Grabbable” and give them a rigidbody for physics

SixenseHandController.cspublic class SixenseHandController : SixenseObjectController{

public float minGrabDistance = 1.0f;// Grabbable object must be within this distance from hand colliders to be picked uppublic float throwForce = 30.0f;

// Force multiplyer for throwing objects

private bool isHoldingObject = false;private GameObject closestObject = null;private GrabObject grabObject;

// Script attached to grabbed object with grappling data on that objectprivate float handVelocity;private Vector3 handVector;private Vector3 handPrevious;

…

SixenseHandController.cs (2)protected override void UpdateObject( SixenseInput.Controller controller ){

…

if ( controller.Enabled ) {

// Animation updateUpdateAnimationInput( controller );

// Action updateUpdateActionInput ( controller );

}

base.UpdateObject(controller);}

…

SixenseHandController.cs (3)protected void UpdateActionInput( SixenseInput.Controller controller) {

Vector3 currentPosition = new Vector3();Quaternion currentRotation = new Quaternion();

Velocity();

if (isHoldingObject && !controller.GetButton(SixenseButtons.TRIGGER)) {Throw();

isHoldingObject = false;}

if (Hand == SixenseHands.LEFT) {currentPosition = GameObject.Find("LeftHandCollider").transform.position;currentRotation = GameObject.Find("LeftHandCollider").transform.rotation;

}if (Hand == SixenseHands.RIGHT) {

currentPosition = GameObject.Find("RightHandCollider").transform.position;currentRotation = GameObject.Find("RightHandCollider").transform.rotation;

}

SixenseHandController.cs (4)if (!isHoldingObject) {

foreach (GameObject o in GameObject.FindGameObjectsWithTag ("Grabbable"))

{float dist = Vector3.Distance(o.transform.position, currentPosition);if (dist < minGrabDistance) {

closestObject = o;}

}}

SixenseHandController.cs (5)if (closestObject != null && Vector3.Distance(closestObject.transform.position, currentPosition) < minGrabDistance && controller.GetButton(SixenseButtons.TRIGGER)) {

if (closestObject.rigidbody && closestObject.rigidbody.isKinematic) {return;

}

grabObject = closestObject.GetComponent<GrabObject>();if (grabObject && grabObject.isEnabled) {

closestObject.transform.position = currentPosition + grabObject.GetPosition(Hand);

closestObject.transform.rotation = currentRotation * Quaternion.Euler(grabObject.GetRotation(Hand));

} else {closestObject.transform.position = currentPosition;closestObject.transform.rotation = currentRotation;

}

isHoldingObject = true;}

}

SixenseHandController.cs (6)// Calculate velocity of handprotected void Velocity () {

if (Time.deltaTime != 0){

handVector = (transform.position - handPrevious) / Time.deltaTime;handPrevious = transform.position;

}

handVelocity = Vector3.Magnitude(handVector);}

// Throw the held object once player lets go based on hand velocityprotected void Throw () {

if (closestObject.rigidbody) {Vector3 dir = (closestObject.transform.position - transform.position).normalized;

closestObject.rigidbody.AddForce(dir * handVelocity * throwForce);}

}

Next• Presentation slides will be up online• Project will be open sourced once beta is

completed• YouTube video showing a play through

Future• Integrate alternative and supporting devices

i.e. STEM, Leap Motion, MYO, Omni +• Re-make further (complete?)• Boilerplate?• Re-create other classics (Super Smash Bros?)