onGameStart 2013: Workshop

Will Eastcott, Co-founder
@willeastcott

Agenda

PlayCanvas Brain Dump
90 minutes

Break 

Exercise: Duplicate a Simple Game
90 minutes

Lunch

FreeStyle Game Jam!
All afternoon

A brief history of will

1998-2004: Criterion software


Senior Software Engineer: RenderWare
Head of Consultancy

2004-2007: EA


Product Manager: RenderWare Physics

2007-2009: SonY


Consultant: PlayStation Home

2009-2011: Activision

Technical Director for Europe

What is PlayCanvas?




A cloud-hosted, collaborative, 3D game engine 
powered by HTML5 

WHY DEVELOP in the cloud?

  • Access your projects from any device
  • Collaborate in realtime with your team
  • Get instant help and feedback
  • Browse and iterate public projects

Terminology

  • Pack - A level or scene.
  • Entity - A thing in your game.
  • Component - Adds behavior to an entity.
  • Attribute - A property of a component.

Logging in for the first time

Graphics

  • Ambient, directional, point and spot lights
  • Static and skinned meshes (up to 256 bones)
  • Wireframe rendering
  • Map types: diffuse, specular, emissive, normal
  • Per-pixel fog
  • Skyboxes
  • Full screen effects

Primitives

Basic shapes: box, sphere, cylinder, cone, capsule
Very useful for prototyping
Can make entire games with them:

Models

3D content that you upload to PlayCanvas

Recommendations:
Supply models in FBX format
Ensure textures are embedded in FBX
Ensure no meshes have >65535 vertices

Material Editing

You can edit materials in Designer
Click once to select entity
Click again to select the material on selected mesh

Shadows

Shadows add realism to your scene

Let's take a closer look in PlayCanvas Designer

Limitations

Keep the number of dynamic lights low
There is a light budget and each light type has a 'cost'
Directionals are cheapest, then points, then spots

Known Issues

You cannot set ambient light level or fog from Designer
Can only be done in script

Ambient Light
            context.scene.setGlobalAmbient(0.3, 0.3, 0.3);

Fog
            context.graphicsDevice.updateGlobalState({
                fog: true,
                fogDensity: 0.02
            });

This will be fixed soon!

Cameras

Represent your game's viewpoint

Perspective Cameras


ORTHOGRAPHIC CAMERAS


Let's Try It!

  1. Create a new Pack
  2. Rename root node 'Cameras'
  3. Create a new Entity
  4. Add a primitive component.
  5. Create a new Camera
  6. Position the camera to view primitive
  7. Launch!

Scripting

  • Add custom behavior to entities
  • JavaScript API

Workflows

2 available options:

  1. Edit scripts on playcanvas.com
  2. Edit scripts on your filesystem
    and sync using Github or Bitbucket

Scripting on playcanvas.com


Scripting via GitHub/BitBucket


Scripting via GitHub/BitBucket


Anatomy of a Script

ENTITY COMMUNICATION


To summarise:
var e = context.root.findByName(entityName);
e.script.send(scriptName, functionName, arg1, arg2 ... argN);

Debugging Scripts


Debugging Scripts


Take Care in the Script Editor


Collaborative script editing is not yet enabled
If you are working with other coders, be mindful that the most recent save overwrites the previous
TO BE RESOLVED VERY SOON!

Physics

Allows you to quickly create complex and
realistic behavior and interactions

Rigid BOdy

Idealised representation of a body
in which deformation is ignored

Properties:
  • position and orientation
  • linear and angular velocity
  • mass, friction, restitution


Actions:
  • apply forces and impulses
  • apply torque and torque impulses

Body Types

  • Static
  • Dynamic
  • Kinematic


Let's see each type in action...

Collision Primitives

A body needs to be linked to a collision primitive:

  • Sphere
  • Box
  • Capsule
  • Triangle Mesh


Let's take a look

Ray Casting

  • Visibility checks
  • Lasers
  • Character controllers   
    checkGround: function () {
    var self = this;
    var start = this.entity.getPosition();
    var end = pc.math.vec3.create();
    var groundCheckRay = pc.math.vec3.create(0, -1.1, 0);

    pc.math.vec3.add(start, groundCheckRay, end);
    this.onGround = false;

    // Fire ray straight down to just below the bottom of rigid body
    // If it hits something, the character is on the ground
    context.systems.rigidbody.raycastFirst(start, end, function (res) {
        self.onGround = true;
    });
}

    Contact Detection

    Useful for triggering events
    e.g. audio, particles

            initialize: function () {
            context.systems.rigidbody.on('contact', function (result) {
                var a = result.a;
                var b = result.b;
                var namea = a.getName();
                var nameb = b.getName();
                console.log(a + ' has collided with ' + b);
            });
        },

    Let's Try It!

    1. Create a new pack
    2. Rename root node 'Physics'
    3. Create a camera
    4. Create a static floor
      (components: primitive, collisionbox and rigidbody)
    5. Create a dynamic ball above floor
      (same components as above)
    6. Set ball rigid body type to 'Dynamic'
    7. Launch!

    Audio


    Brings your game to life more
    than you might think.

    Don't make it an afterthought!

    Supported Formats

    PlayCanvas doesn't currently   handle multiple audio formats
    Pick what works best based on your audience

    Format Chrome Firefox IE Opera Safari
    WAVE, PCM ✔ ✔ ✘ ✘ ✔
    WebM, Vorbis ✔ ✔ ✘ ✔ ✘
    Ogg, Vorbis ✔ ✔ ✘ ✔ ✘
    MP4, MP3 ✔ ✔ ✔ ✘ ✔
    MP4, AAC ✔ ✔ ✔ ✘ ✔

    Referenced from mozilla.org

    DEMO: 3D Audio


    Sources and Listeners

    Listener component locates your ear in 3D space
    Normally assigned to the game camera
    Sources play back sound FX

    Controlling Audio from Script


    Example 1: trigger audio on some event
    update: function (dt) {
    if (context.keyboard.wasPressed(pc.input.KEY_SPACE) && onGround) {
        this.entity.audiosource.play('jump_sound');
    }
}

    Example 2: modify audio source properties over time
    update: function (dt) {
    this.timer += dt;
    this.entity.audiosource.volume = Math.sin(this.timer) * 0.5 + 0.5;
}

    Finding Content

    Publishing

    Get people playing your games!
    (That's the point, right?)

    Getting the Word Out

    Case Study: Doom 3 Gangnam Style
    Twitter/Facebook
    webgl.com
    Chrome Experiments
    Reddit
    Hacker News

    Monetization

    Publish to the Web
    Self-publish or publish on PlayCanvas
    Take advantage of the Chrome Web Store

    Use payment providers like PayPal and Google Wallet

    Monetization

    Publish to App Stores



    HTML5 to Native App

    Export and download your PlayCanvas app
    Package using HTML5 native wrapper tech
                      
    Take care!
    CocoonJS and Ejecta can only handle 1 canvas
    Performance is lower than native


    onGameStart 2013: Workshop

    Will Eastcott, Co-founder
    @willeastcott

    Exercise
    Duplicate Pong (Easy)

    or

    Duplicate Asteroids (Hard)

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