FliNT particle system

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1 Introduction

Learning goals
Prerequisites
Environment
  • Flash CS3
Moving on
Level and target population
  • Absolute ActionScript beginners (but see the prerequisites). This tutorial is meant for Flash designers working with CS3, CS4, CS5 etc. and are willing to learn some ActionScript in order to reuse Flint example code to create special effects.
Quality
  • useable, but under progress.
To Do
  • Other examples

2 The FliNT particle system

“Flint is an open-source project to create a versatile particle system in ActionScript 3. The aim is to create a system that handles the common functionality for all particle systems, has methods for common particle behaviour, and lets developers extend it easily with their own custom behaviours without needing to touch the core code. ([1])”. That may sound very technical and it actually is. Such libraries are meant primarily for "real" ActionScript programmers. However, Flash designers with a little bit of ActionScript programming know-how can also use such code. In particular, they simply may slightly adapt the excellent examples that are for download.

Flint is developed by Richard Lord and is released under the free open source MIT licence.

Firstly have a look at what this particle system can do. Cool isn't it ?

2.1 Download and install the Flint system

Step 1 - download

As of oct 2009: Flint_2_1_2_swc.zip
  • Dezip the file.

Step 2 - You may install it into the Flash Components directory, e.g. for CS4/Vista:

  • Close Flash Professional (e.g. CS4)
  • Copy the directory that includes the files Flint2d.swc and Flint3d.swc to the components directory of your flash installation, e.g. in CS4/VISTA:
C:\Programs\Adobe\Adobe Flash CS4\Common\Configuration\Components

The directory now should look like this:

 c:\Program Files\Adobe\Adobe Flash CS4\Common\Configuration\Components:
             0 Nov 26  2008 Data
             0 Oct 15 18:39 Flint_2_1_2_swc
             0 Nov 26  2008 Media
             0 Nov 26  2008 User Interface
       1778688 Sep 09  2008 User Interface.fla
             0 Oct 01 15:22 Video
        306176 Sep 09  2008 Video.fla

Open CS4 again, your components panel now should include the Flint classes. This is probably a dumb thing to do, but the advantage is that you can remember that you have these libraries and where ;) Anyhow, putting these files there, will not change a thing with respect to the next step .....

Step 3 - Fix the source path

2.2 Alternative: Install the source

Skip this step if you took the *.swc files !

Step 1 - download the FliNT particle system

Get a zip file of FliNT source from http://flintparticles.org/. took:

You also may download extra stuff, i.e. documentation and examples (both can be found in the same place)

Dezip these three archives in a new directory.

Now since we are interested in snowflakes were are actually really lucky. There is both example code (in the example zip file) and a nice Introducing Flint with a snow effect tutorial made by Richard Lord the author of the Flint system.

Step 2 - create a new Flash (ActionScript 3.0) file
  • Create a new directory for this project
  • Make sure that you really use ActionScript 3.0, else change that in the File->PublishSettings - Flash tab too.
  • If you want, you can move the "src" sub-directory of the Flint system to the root of this new directory and rename it to something like "flint"

2.3 Let's snow

You might want snowflakes. Creating a nice snowing animation with lots of snowflakes by drawings would be very tedious and programming them yourself is a bit difficult (unless you are a "real" programmer). You now have two options:

  1. Finding some special purpose snowflakes code on the web
  2. Using a more general purpose library that will create the whole animation (including the snowflakes), something that you will learn now. Basically we just copy/paste the code from Introducing Flint with a snow effect. Or more precisely we took the example code from the downloaded Flint_2_0_0_b_examples.zip on oct 23, 2008 and made 2-3 tiny modifications.
Step 0 - Fix the Classpath in Flash
  • Open the File->Publish Settings - Flash tab
  • Then click on the Settings ... button next to the ActionScript version. You should see something like this now:
Setting the classpath in Flash CS3


In these ActionScript 3.0 settings, you then have to add the name of the subdirectory where the flint system sits.

Important differences:

  • If you are working with the source code version of Flint, then open the source path tab (by default it's open), then click on the "target" Browse to Path icon and select the "src" directory of the FliNT system.
  • If you work with the svc version (compiled), then select libary path and select the place where the swc library sits. e.g. the "dumb" place I put it into:
C:\Program Files\Adobe\Adobe Flash CS4\Common\Configuration\Components\Flint_2_1_2_swc

Basically, what you have to understand at this point is that your application has to know in which directory to look for the FliNT code. The "org" subdirectory of the source code version must be a direct sub-directory of the classpath directory you just defined. If you want to understand more about packages and classes you'll have to dig fairly deeply into ActionScript programming, something we will not do here ...

Step 1 - Create a frame for which you want snowfall.
  • Firstly you need a typical winter scene, e.g. a nice photo, such as the one that you can see in the original example made by Richard Lord. A local copy of the swf is here).

Personally, I'd like to have some snow in my Office as you can see in our own version. So firstly we need to import a picture. I made the orginal much darker with higher contrasts in order to be able to see the snowflakes. It may be too dark on your screen, but on my DELL M1730 laptop it looks just fine.

  • This picture is now in frame one of layer 1. Rename the layer to picture.
  • Add a new layer and call it script.
Step 2 - Add the Action Script
  • Click in frame 1 of the script layer, hit F9 and copy/paste the following code. You also must include the copyright notice. I believe that we really are lucky to be able to use such libraries. So please, be respectful !
/*
 * FLINT PARTICLE SYSTEM
 * .....................
 * 
 * Author: Richard Lord
 * Copyright (c) Big Room Ventures Ltd. 2008
 * http://flintparticles.org/
 * 
 * Licence Agreement
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 */

import org.flintparticles.common.counters.*;
import org.flintparticles.common.displayObjects.RadialDot;
import org.flintparticles.common.initializers.*;
import org.flintparticles.twoD.actions.*;
import org.flintparticles.twoD.emitters.Emitter2D;
import org.flintparticles.twoD.initializers.*;
import org.flintparticles.twoD.renderers.*;
import org.flintparticles.twoD.zones.*;

// We keep the same here - unlike the original
// addChild( new SnowBackground() );

var emitter:Emitter2D = new Emitter2D();

emitter.counter = new Steady( 150 );

emitter.addInitializer( new ImageClass( RadialDot, 2 ) );
// Modified DKS - our picture is a bit larger
// emitter.addInitializer( new Position( new LineZone( new Point( -5, -5 ), new Point( 605, -5 )) ) );
emitter.addInitializer( new Position( new LineZone( new Point( -5, -5 ), new Point( 645, -5 ) ) ) );
emitter.addInitializer( new Velocity( new PointZone( new Point( 0, 65 ) ) ) );
emitter.addInitializer( new ScaleImageInit( 0.75, 2 ) );

emitter.addAction( new Move() );
// Modified DKS - our picture is a bit larger
// emitter.addAction( new DeathZone( new RectangleZone( -10, -10, 620, 420 ), true ) );
emitter.addAction( new DeathZone( new RectangleZone( -10, -10, 645, 485 ), true ) );
emitter.addAction( new RandomDrift( 20, 20 ) );

var renderer:DisplayObjectRenderer = new DisplayObjectRenderer();
renderer.addEmitter( emitter );
addChild( renderer );

emitter.start();
emitter.runAhead( 10 );

// We keep the same here - unlike the original
// addChild( new SnowForeground() );

That was really easy. We just took the code from the Flint_2_0_0_b_examples.zip archive and made 2 little modifications. We only use a single background and commented out 2 lines. Also, we changed two parameters since our picture is a bit bigger.

Step 3 - Error messages ?

If you see something like this:

Scene1, Layer 'Script', Frame 1, line 22 
1172: Definition org.flintparticles.common.counters could not be found.

then you most likely got your classpath definition wrong. See above !

If it isn't snowing all over your picture, then you will have to adjust 2 lines in the AS3 code. Figure it out yourself by looking at our inserted comments in the AS code above. Also you should get the DeathZone right. This is a hidden area underneath the picture where the falling down flakes are killed.

Result and source code

The result:

Get the flint-snowflakes.fla file from the following places. But please recall that you will have to set the classpath (aka source-path) for the FLiNT library. It will not work "as is" !

There is no difference between CS3 and CS4 versions, except that one can't open CS4 files in CS3.

Want to understand a bit more ?

Read the Introducing Flint with a snow effect tutorial made by Richard Lord.

Our only contribution was to add some explanations on how to define a classpath, i.e. the very basics about how to reuse such an example and which R.L. doesn't explain (since he made this library for programmers and not designers in the first place).

2.4 Burning Logos

Something else you can with this particle system is to create burning Logos, e.g. something that symbolizes how hot the master program you should join is.

The example below is just a adaptation of the example distributed in the Downloads. You also can look at the maybe different online version of the burning Flint Logo.

To create your own burning logo you need two things:

  • A *.png file with a logo. This file must have the following properties
    • Background color should be Alpha channel. In GIMP for example, menu Colors->Color to Alpha, then select the color, e.g. white if your drawing is orange on white. Else your whole picture will burn.
    • Color of the letters should be orange (FF9900) unless you make more changes to the code.
  • A "fireblob", i.e. a small graphic with a radial color gradient (see the Flash colors tutorial). You can just copy the one that you will find in the source code of this example.
Step 1 - Import logo and the fireblob to your library
  • Create a logo and put in the library (just the drag the png from the file explorer into the library)
  • Copy the blob from our fla file
Step 2 - Make these linkable classes
  • This is already done for the fireblob
  • Right click on the icon of the *.png bitmap in the library and select linkage
  • Type "Logo" (not LOGO or anything else) and check "Export for ActionScript" then hit OK
 Class: Logo

You now should have a setup that looks like this (minus the fire log which we shall create below). Enlarge the picture below if you can't make out the details.

Setting up a linkage property for the Logo to set on fire


Step 3 - Copy some ActionScript code and make a few adjustments
  • Click on Frame 1 and hit F9, then paste the code you will find below

You then have to make adjustments where I inserted comments:

  • Set the size of the Logo (just look it up in the properties of the graphic in the library)
var bitmapData:BitmapData = new Logo( 332, 99);
  • Position the Logo, wherever you want it to be
bitmap.x = 35;
bitmap.y = 35;
  • Position the Fires, should be the same as above
emitter.x = 35;
emitter.y = 35;

Code to copy/paste:

/*
 * FLINT PARTICLE SYSTEM
 * .....................
 * 
 * Author: Richard Lord
 * Copyright (c) Big Room Ventures Ltd. 2008
 * http://flintparticles.org/
 * 
 * Licence Agreement
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 */

import org.flintparticles.common.debug.*;
import org.flintparticles.common.actions.*;
import org.flintparticles.common.counters.*;
import org.flintparticles.common.displayObjects.RadialDot;
import org.flintparticles.common.initializers.*;
import org.flintparticles.twoD.actions.*;
import org.flintparticles.twoD.emitters.Emitter2D;
import org.flintparticles.twoD.initializers.*;
import org.flintparticles.twoD.renderers.*;
import org.flintparticles.twoD.zones.*;	
import org.flintparticles.common.energyEasing.TwoWay;

// Look up the dimensions of your logo (Right-click in the library->Properties)
var bitmapData:BitmapData = new Logo( 332, 99);
var bitmap:Bitmap = new Bitmap();
bitmap.bitmapData = bitmapData;
addChild( bitmap );
// Position the bitmap graphic on the scene
bitmap.x = 35;
bitmap.y = 35;

var emitter:Emitter2D = new Emitter2D();
emitter.counter = new Steady( 600 );

emitter.addInitializer( new Lifetime( 0.8 ) );
emitter.addInitializer( new Velocity( new DiscSectorZone( new Point( 0, 0 ), 10, 5, -Math.PI * 0.75, -Math.PI * 0.25 ) ) );
emitter.addInitializer( new Position( new BitmapDataZone( bitmapData ) ) );
emitter.addInitializer( new ImageClass( FireBlob ) );

emitter.addAction( new Age( TwoWay.quadratic ) );
emitter.addAction( new Move() );
emitter.addAction( new Accelerate( 0, -20 ) );
emitter.addAction( new ColorChange( 0xFFFF9900, 0x00FFDD66 ) );
emitter.addAction( new ScaleImage( 1.4, 2.0 ) );
emitter.addAction( new RotateToDirection() );

var renderer:BitmapRenderer = new BitmapRenderer( new Rectangle( 0, 0, 500, 200 ) );
renderer.addEmitter( emitter );
addChild( renderer );

// The fire must be in the same position as the bimap
emitter.x = 35;
emitter.y = 35;
emitter.start( );
Step 4 - Admire the result and play with the source code
Step 5 - Change colors

Maybe you may rather want to demonstrate how burning cool your institutions is. All you need to do is make a Logo in blue and then change a line in the AS3 code.

To change the color of the fire emitter, you have to understand that the ColorChange class wants 2 arguments: The color of Logo and the color of the bright parts of the flames. That being said, you can use any colors you want of course. So we change this orange fire:

 emitter.addAction( new ColorChange( 0xFFFF9900, 0x00FFDD66 ) );

into a blue cool fire:

 emitter.addAction( new ColorChange( 0xFF0000FF, 0x00DDFFFF ) );
Step 6 - reuse these logos as movie clips

In principle you should be able to import *.swf "movies" to the library and then use them like internal movie clips, but I wasn't able to import these into the library for a reason I don't understand yet (Flash doesn't give any feedback, it just doesn't import).

Instead I'll show you how to have multiple Logos on fire within a same Flash file. All you need is to create embedded movie clips for each Logo and then attach an AS3 script to each of these. See the Flash embedded movie clip tutorial if don't know how to create embedded movie clips.

Some hints (for the rest, please dig into the fla file below):

  • Registration point of the embedded movie clips should be in the upper left
  • x and y coordinates for the fire animation should be 0 (see the AS3 code in the Fla file)
  • Also in one AS code the Class representing the Bitmap was renamed to Logo2. This also requires a change in one of the scripts.

Results:

Of course, this needs some tuning, e.g. it's too fast and the frame rate is too low and it's otherwise ugly. Anyhow, I wouldn't join a degree program that banks on the effect of a Flash Logo ;)

2.5 Playing around with the other FliNT examples

The Flint examples all come in two versions, either Flash or PureAS3. Go for the Flash version (unless you want to learn how to play with Flex in which case you will have to start reading the Adobe Flex and AS3 Compiling a program tutorials in this wiki).

The Flash version examples usually have just a single line in the script code that you insert in frame 1:

include Frame1.as

This instruction simply includes the contents of the file "Frame1.as" that you will find in the same directory. In our examples above we just copy/pasted the contents of these *.as files into the AS script. The result is the same, but the strategy of including an *.as file is smarter if you plan to reuse your code and if your prefer to use a different editor. We included the code in the *.fla for the simple reason that this way you only need to grab a single file.

To play with the examples in the Flash CS3 environment, the only thing you will have to do is to open the respective *.fla and then fix the classpath, i.e. tell Flash where the Flint_xxxx/src directory is located. E.g. if you need a firework, open in CS3 the

Flint_2_0_0_b_examples/examples2D/Firework/Flash/Firework.fla

Then fix the classpath as described in the Let's snow example

Finally hit CTRL-Enter or publish.

Notice: The resulting swf always will include all the necessary ActionScript code, i.e. you won't have to copy the Flint files to the server.

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