Tag Archives: move

Jumping in a 2D game with ground check in Unity

In this tutorial, you will learn how to write a script in C# code that allows your player to jump only when they are touching the ground.

Watch the video below and scroll down to view the sample code.

Sample code

using UnityEngine;
using System.Collections;

public class PlayerController : MonoBehaviour {

  public float speed = 5f;
  public float jumpSpeed = 8f;
  private float movement = 0f;
  private Rigidbody2D rigidBody;
  public Transform groundCheckPoint;
  public float groundCheckRadius;
  public LayerMask groundLayer;
  private bool isTouchingGround;

  // Use this for initialization
  void Start () {
    rigidBody = GetComponent<Rigidbody2D> ();
  }
  
  // Update is called once per frame
  void Update () {
    isTouchingGround = Physics2D.OverlapCircle (groundCheckPoint.position, groundCheckRadius, groundLayer);
    movement = Input.GetAxis ("Horizontal");
    if (movement > 0f) {
      rigidBody.velocity = new Vector2 (movement * speed, rigidBody.velocity.y);
    }
    else if (movement < 0f) {
      rigidBody.velocity = new Vector2 (movement * speed, rigidBody.velocity.y);
    } 
    else {
      rigidBody.velocity = new Vector2 (0,rigidBody.velocity.y);
    }

    if(Input.GetButtonDown ("Jump") && isTouchingGround){
      rigidBody.velocity = new Vector2(rigidBody.velocity.x,jumpSpeed);
    }
  }
}

Next tutorial: Changing the player sprite

Making the player jump in a 2D game with Unity and C# code

In this tutorial you will learn how to write a script to make your player jump in a 2D game with C# code in Unity. In the following tutorial, you will learn how to make the player jump only when they are touching the ground.

Watch the video below and scroll down to view the sample code.

Sample code

using UnityEngine;
using System.Collections;

public class PlayerController : MonoBehaviour {

  public float speed = 5f;
  public float jumpSpeed = 8f;
  private float movement = 0f;
  private Rigidbody2D rigidBody;

  // Use this for initialization
  void Start () {
    rigidBody = GetComponent<Rigidbody2D> ();
  }
  
  // Update is called once per frame
  void Update () {
    movement = Input.GetAxis ("Horizontal");
    if (movement > 0f) {
      rigidBody.velocity = new Vector2 (movement * speed, rigidBody.velocity.y);
    }
    else if (movement < 0f) {
      rigidBody.velocity = new Vector2 (movement * speed, rigidBody.velocity.y);
    } 
    else {
      rigidBody.velocity = new Vector2 (0,rigidBody.velocity.y);
    }

    if(Input.GetButtonDown ("Jump")){
      rigidBody.velocity = new Vector2(rigidBody.velocity.x,jumpSpeed);
    }
  }
}

Next tutorial:  Jumping with ground check

Moving the player in a 2D game with Unity and C# code

This video explains how to move your player in a 2D game in Unity with C# code. After watching this video, you will be able to move your player left and right in a scene using keyboard input.

Watch the video below and scroll down to see the sample code.

Sample code

using UnityEngine;
using System.Collections;

public class PlayerController : MonoBehaviour {

  public float speed = 5f;
  private float movement = 0f;
  private Rigidbody2D rigidBody;

  // Use this for initialization
  void Start () {
    rigidBody = GetComponent<Rigidbody2D> ();
  }
  
  // Update is called once per frame
  void Update () {
    movement = Input.GetAxis ("Horizontal");
    if (movement > 0f) {
      rigidBody.velocity = new Vector2 (movement * speed, rigidBody.velocity.y);
    }
    else if (movement < 0f) {
      rigidBody.velocity = new Vector2 (movement * speed, rigidBody.velocity.y);
    } 
    else {
      rigidBody.velocity = new Vector2 (0,rigidBody.velocity.y);
    }
  }
}

Next tutorial: Making the player jump with C# code

Moving an object with force in PlayCanvas

This tutorial explains how to use keyboard input to move an object around. But rather than telling the object how far it needs to move (like in this other tutorial), we will apply force to the object instead. This means that the object your moving can also hit other objects and interact with them rather than just going through them.

Step 1 – Setting up the object you want to move

To begin with, you need to create an object or use a model that you want to move. Then you need to add a Rigid Body component and a Collision component so that this object can collide and interact with other objects in the scene. For this example, I have added a Box entity (click + in the Hierarchy and then click Box) but you can use another 3D shape or model.

3dobject
Then you need to select the object and click on Add Component (in the Inspector panel on the left side of the screen) and choose the Collision component. If you have a box shape (entity) then you should set the Collision Type to Box (if you have a sphere shape, then select Sphere for Type, and so on).

Match your collision settings up so they look like the settings shown below. The numbers in the Half Extents property boxes should be half the numbers in the Scale property boxes above it. Eg. if the scale X property of the box has a value of 4 then the Half Extents X value should be 2.

box_collision

Now click on Add Component again and this time add the Rigid Body component. Change the Type to Dynamic and modify the values so they are the same as those below (experiment with these values later to get the effect you want).

rigid_body
It is important to make sure any other objects that this object will interact with also have Rigid Body and Collision components attached to them. For example, if you don’t want this object to fall through your ground in the scene, then the ground object should have a Static type Rigid Body and a Collision component.

If you want other objects to not be moved by this object, they should have a Static type Rigid Body and Collision component. Otherwise, if you want this object to move other objects when it touches them, add Dynamic type Rigid Body and Collision components to those other objects.

Adding a script to the object

Click on + in the Assets panel and choose Script to create a new script.

create_script
Call the new script moveWithForce.js and hit Enter to create the script.

script_name

Now you need to attach the script to the 3D object or model you want to move or control. Select the 3D object (eg. box) and then click on Add Component and select Script. Drag the moveWithForce.js script onto the Scripts component on the object in the Inspector panel and then let go. The script should now be attached to the object.

script_attached

 

Writing the code

Double-click on the moveWithForce.js script you just created in the Assets panel and replace all of the existing code with the following code in the Code Editor window:

// Add this code to any object you want to move with force
// Object that this script is attached to must have collision component and DYNAMIC rigid body component

pc.script.attribute("power", "number", 1000);  // set power to initial value of 1000
pc.script.create('moveWithForce', function (app) {
    // create force variable
    var force = new pc.Vec3();
    // Creates a new MoveWithForce instance
    var MoveWithForce = function (entity) {
        this.entity = entity;
    };

    MoveWithForce.prototype = {
        // Called once after all resources are loaded and before the first update
        initialize: function () {
            // Check for required components
            if (!this.entity.collision) {
                console.error("First Person Movement script needs to have a 'collision' component");
            }
            
            if (!this.entity.rigidbody || this.entity.rigidbody.type !== pc.BODYTYPE_DYNAMIC) {
                console.error("First Person Movement script needs to have a DYNAMIC 'rigidbody' component");
            }
            
            // Listen for keyboard press events
            app.keyboard.on(pc.EVENT_KEYDOWN, this._onKeyDown, this);
        },

        // Called every frame, dt is time in seconds since last update
        update: function (dt) {

            // movement
            var x = 0;
            var z = 0;
            var y = 0;
            
            // Use W-A-S-D keys to move player around and Space to make player jump
            // Check for key presses
            if (app.keyboard.isPressed(pc.KEY_LEFT)) {
                x -= 0.01;
            }
            
            if (app.keyboard.isPressed(pc.KEY_RIGHT)) {
                x += 0.01;
            }
            
            if (app.keyboard.isPressed(pc.KEY_UP)) {
                z -= 0.01;
            }
            
            if (app.keyboard.isPressed(pc.KEY_DOWN)) {
                z += 0.01;
            }
            
            if (app.keyboard.isPressed(pc.KEY_SPACE)) {
                console.log("space pressed");
                y += 0.05;
            }
            
            // use direction from keypresses to apply a force to the character (x and z axes)
            if (z !== 0) {
                force.set(0, 0, z).normalize().scale(this.power);
                this.entity.rigidbody.applyForce(force);
            }
            
            if (x !== 0) {
                force.set(x, 0, 0).normalize().scale(this.power);
                this.entity.rigidbody.applyForce(force);
            }
            
            // use direction from keypresses to apply a force to the character (y axis)
            if (y !== 0) {
                force.set(x, y, z).normalize().scale(this.power);
                this.entity.rigidbody.applyForce(force);
            }
        },
        
        _onKeyDown: function (event) {
            // When the space bar is pressed this scrolls the window.
            // Calling preventDefault() on the original browser event stops this.
            event.event.preventDefault();
            console.log("Scrolling disabled");
        }
    };

    return MoveWithForce;
});

Now click on Save and then go back to the game Editor window. That’s it! Launch your game by clicking on the Launch (play) button and you should now be able to control the 3D object/model by using the keyboard to move it around and make it jump. The code is set up to move the object using the arrow keys and space bar to jump. However, you can change these keys and you can also remove the code that makes the object jump if you don’t want to make it jump in the game.

 

 

 

Moving objects with keyboard input in PlayCanvas

If you watched the previous tutorial you would have learned how to make an object move on its own using JavaScript code. In this tutorial, we will make an object move around using keyboard input. That is, if the left arrow key is pressed on the keyboard then we can make the object move left. If the right arrow key is pressed on the keyboard then we can make the object move right, and so on…

Keyboard input will be very useful in your games eg. to make a player jump, to move around, pick up objects or enter your name in the high score book! Watch the video to find out how to add keyboard input to your games and then try out the sample code further down the page.

Here is the sample code for this tutorial. Make sure you create a new script asset called move.js and then add it as a component to your 3D object (eg. a box). Then add the code to the move.js script.

In the code, you will see app.keyboard.isPressed – this will check if the key is being pressed during the current frame. If you hold down the key, the object will keep moving. If you use another method called app.keyboard.wasPressed instead it will only check if the key was pressed in the current frame (it will detect one keypress and won’t keep the object moving when you hold the key down).

pc.script.create('move', function (app) {
 // Creates a new Move instance
 var Move = function (entity) {
 this.entity = entity;
 };
 
 Move.prototype = {
 // Called once after all resources are loaded and before the first update
 initialize: function () {
 },
 
 // Called every frame, dt is time in seconds since last update
 update: function (dt) {
 if(app.keyboard.isPressed(pc.input.KEY_RIGHT)){
 this.entity.translateLocal(0.1,0,0);
 }
 
 if(app.keyboard.isPressed(pc.input.KEY_LEFT)){
 this.entity.translateLocal(-0.1,0,0);
 }
 
 if(app.keyboard.isPressed(pc.input.KEY_UP)){
 this.entity.translateLocal(0,0.1,0);
 }
 
 if(app.keyboard.isPressed(pc.input.KEY_DOWN)){
 this.entity.translateLocal(0,-0.1,0);
 }
 }
 };
 
 return Move;
});

Make a 3D object move with code in PlayCanvas

In this tutorial we will start writing our very lines of JavaScript code in the PlayCanvas code editor! To start with, we will make a 3D object (eg. a box or sphere) move around the screen on its own. Watch the video below and then scroll down to see the sample code and try it out for yourself.

Here is the sample code for this tutorial. Make sure you create a new script asset called move.js and then add it as a component to your 3D object (eg. a box). Then add the code to the move.js script. Launch your game and then watch the object start moving to the right (if your object moves to the left, then your camera is on the opposite side of the object). Try changing the x, y, and z translateLocal parameters to make your object move in different directions at different speeds.

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pc.script.create('move', function (app) {
 // Creates a new Move instance
 var Move = function (entity) {
 this.entity = entity;
 };
 
 Move.prototype = {
 // Called once after all resources are loaded and before the first update
 initialize: function () {
 },
 
 // Called every frame, dt is time in seconds since last update
 update: function (dt) {
 this.entity.translateLocal(0.01,0,0);
 }
 };
 
 return Move;
});

Getting started with PlayCanvas

PlayCanvas is a 3D game development environment in the cloud. You can use PlayCanvas to make your own 3D games and code them in the JavaScript programming language using a web browser like Chrome or Firefox.

In this tutorial you will learn about the PlayCanvas features and tools and how to create, move, rotate, and resize 3D shapes. Watch the video below to get started with PlayCanvas.

Transforming objects using scripts

This video tutorial will show you how to transform objects (move, rotate, scale) in your Unity game using C# scripts and also how to implement player interaction with the game by allowing players to transform objects using keypresses on their keyboard.

Watch the video below and then scroll down to see the sample code.

Here is some sample code with different object transformations assigned to different keypresses on the keyboard. You can change the transformations and assigned keys although it is a good idea to use the input manager rather than specific keypress detection so that your players have the option of remapping keys to suit their own preferences.

using UnityEngine;
using System.Collections;
 
public class move : MonoBehaviour {
 
 // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void Update () {
 if (Input.GetKey (KeyCode.W)) {
 transform.Translate (0f,0f,0.1f);
 }
 if (Input.GetKey (KeyCode.S)) {
 transform.Translate (0f,0f,-0.1f);
 }
 
 if (Input.GetKey (KeyCode.D)) {
 transform.Translate (0.1f,0f,0f);
 }
 if (Input.GetKey (KeyCode.A)) {
 transform.Translate (-0.1f,0f,0f);
 }
 
 if (Input.GetKey (KeyCode.Z)) {
 transform.Rotate (0f,1f,0f);
 }
 
 if (Input.GetKey (KeyCode.X)) {
 transform.Rotate (0f,-1f,0f);
 }
 
 if (Input.GetKey (KeyCode.C)) {
 transform.localScale = new Vector3(1f,1f,1f);
 }
 
 if (Input.GetKey (KeyCode.V)) {
 transform.localScale = new Vector3(5f,5f,5f);
 }
 
 }
}

Note: If you find that the values for x, y and z axes seem to work the opposite to what you expect, it might be because you have the camera at a different angle. For example, if your camera is on the opposite side of your object, then pressing the key that is meant to move the object left might actually move it to the right.

Now try using variables to store the values for speed, eg:

using UnityEngine;
using System.Collections;
 
public class move : MonoBehaviour {
 
 public float turnSpeed = 5.0f;
 public float forwardSpeed = 0.25f;
 
 // Update is called once per frame
 void Update () {
 transform.Rotate(turnSpeed, 0.0f, 0.0f);
 transform.Translate(0.0f, 0.0f, forwardSpeed);
 }
}

Here is another method of moving objects on their own at a steady speed (this example does not include keyboard input).

using UnityEngine;
using System.Collections;
 
public class moveCube : MonoBehaviour {
 
 public float speed = 1.0f;
 
 // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void Update () {
 transform.Translate (Vector3.forward * speed * Time.deltaTime);
 // This will move the cube forward on its own at steady speed
 // Vector3 is for 3D , Vector2 is for 2D
 // You can change Vector3.forward to Vector3.back, Vector3.left, or Vector3.right
 
 
 }
}

Creating and animating 3D text in Maya

This video explains how to add text to a scene and then animate it in Maya. You can manipulate text in the same way you manipulate many other 3D objects in Maya – you can move (translate), rotate, scale, set keyframes or even animate along a path.

Watch the video below to find out how to create and animate 3D text in Maya.