ActionScript Box2D Quick Start
-
Upload
chris-black -
Category
Technology
-
view
7.086 -
download
2
description
Transcript of ActionScript Box2D Quick Start
Box2D AS3 Quick Start
Chris Black
What is Box2D for Flash?
• “Box2DFlashAS3 is an open source port of Erin Catto's powerful c++ physics library Box2D.”
–Box2DFlash
• Current version 2.0.1 Flash and 1.4.3.1 for JavaScript.
• Box2D can be used to quickly add ‘real life’ physics to your Flash / Flex projects.
Uses of Box2D
• Games, physics demos and… games.• Very little practical application outside of
games.• Clients looking for animation often feel Box2D
looks too ‘real.’
AS3 Physics Comparison
• For a great comparison on physics engines available for Flash check out this post:
• http://www.emanueleferonato.com/2008/04/24/flash-physics-engines-galore/
Box2D vs Flash CS5
• Flash CS5 has a built in engine for creating STATIC demos.
• Box2D should be used when user interaction is required for DYNAMIC apps.
• If your animation changes based on user interaction, use Box2D.
Getting Started
• Grab the quick start demo from Google Code
Starting from scratch:• Add the SWC or download Box2D source• Set up your constants• Create a world with boundries• Add objects to the world
Constants
public static const PHYS_SCALE:Number = 10;// Number of pixels in a Meter.
public static const TIMESTEP:Number = 1.0 / 15.0;// How many physical calculations per timestep.
Usually 1 / 15 or 1 / 60.
public static const ITERATIONS:Number = 10.0;// The suggested iteration count is 10.
Create a World
2D Object VO
Create an Object
Add Object to the World
Demo
Basketball Demo
Car Demo
Box2D for Android
• GPU Acceleration• CacheAsBitmapMatrix• 30 fps on the Nexus One• Video demo on Nexus One
Box2D for iOS
• Box2D doesn’t perform well using the iOS exporter within Flash CS5.
• This might improve with future iterations but for now use native Objective-C for iOS apps that require physics.
Box2D for JavaScript
• Older version compared to Flash• Doesn’t perform as well on a PC• Takes longer to code• Worth trying out but needs some major
updates before it will compare to Flash.
Now what?
• Downloadhttp://box2dflash.sourceforge.net/http://box2d-js.sourceforge.net/
• Learnhttp://www.emanueleferonato.com/category/box2d/http://www.blackcj.com/blog/tag/box2d/