## Archive for the 'Effect' Category

02
Nov
11

### Creative Javascript – 3D Tree with Leaf-fall

A HTML5 prototype…

Finally getting around to have a play with HTML5 Canvas – enabled by attending Seb Lee Delisle’s excellent CreativeJS course.

I’m impressed with performance from Canvas nowadays – my first sight of it many moons ago left me pretty disappointed – but now it actually feels useful and some pretty impressive visual effects can be achieved without resorting to WebGL.

The prototype I threw together here demonstrates a growing tree, in 3D with numerous branches, leaves, leaf fall, faux-shading and colour phasing. The demo will re-grow a tree on mouse click, and will allow for left and right rotation by means of mouse position (left/right).

3D Tree with Leaf Fall

To talk through the code a little: The tree is constructed using a recursive buildBranch function. Every branch spawns two new branches, or in the last generation it has a 90% chance of spawning a leaf. The branches are coloured from brown to green related by the recorded generation of the branch.

No 3D libraries were used in this demo – all of the 3D is via a simple scaling calculation for 3D points [ fov / (fov + point.z) ]. This allows for any 3D point to be translated (scaled) onto the 2D canvas.

The Painter’s Algorithm (priority fill) is applied via the sorting of all branches and leaves on their mid-point. This means that those furthest away are drawn to screen first.

Shading is applied by mapping colour to the z value of a branch’s position. This is very simply applied. There is a related alpha to add a fog effect to the furthest away elements, this gives some subtle but nasty artefacts and could be improved.

When a branch is fully grown the leaves will then appear and grow to their full size. When they fall a sine value is applied to rotation to make it rock as it falls. Leaves will collect on the ground.

Performance is pretty good here, but I did have to restrict the number of branch generations to 9. Of course some of the out-of-the-box features that Flash has such as Glow and Blur filters don’t exist – which means work-arounds or approximations have to be used – sound implementation isn’t very consistent across browsers – it is still early days, more and more JS will be used across the web, as it is the browser manufacturers will hopefully drive their products into more useful areas and consistent implementations.

The demo is a fast turn-around ‘prototype’, so not optimal or well formed. Feel free to have a play with the code, offer improvement suggestions or adapt in anyway you wish.

No attempt has been made to cover HTML5 cross-browser issues – so don’t expect this to work in IE!

Direct Link: 3D Tree with Leaf Fall

25
Feb
10

### AS3 Flamer Class :: Setting things on fire

The Flamer Class is a quick and easy method to set things on fire. Throw some fuel (any display object) at the class and make it burn.

While working on another project I needed to make some lightweight flames. I looked around, tried a bit of perlin noise, some convolution filters – then some PixelBender filtering – I wasn’t really happy with the results.

I found the excellent Saqoosha’s Fire on Wonderfl.
This demo had nearly the flicker and colour mapping that I was looking for. Rendering the perlin noise on each frame was causing a bit too much processor overhead for my purposes.
Instead of rendering two perlin octaves and moving the layers against each other, I took two separate single octave perlin noise bitmaps and rotated one against the other while blending.
This gives a nice effect and is very lightweight. With the Saqoosha method I was clocking at a steady 26fps, with my lightweight method I could get 90fps.

To get the flame hues I set up a gradient box, threw some colours at it, loaded those colours into an array which I then pushed to a palette map.

So how to use the Flamer class:

import swingpants.effect.Flamer

var flamer:Flamer=new Flamer(display_object)

function enterFrameHandler(event:Event):void
{
flamer.update()
}

Your object will now be on fire. Feel naughty?

You can set the render width and height and also set the direction of the flames by setting a point vector.

var flamer:Flamer=new Flamer(display_object,render_width, render_height, flame_direction_point)

//The colour of the flames can be set with one of the presets (There are 4 at the moment – ORANGE_FLAME, BLUE_FLAME, YELLOW_FLAME, GREEN_FLAME – but I will be adding more)
flamer.setFlameColour(Flamer.BLUE_FLAME)

//Direction can be set on the fly:
flamer.setFlameDirection(direction_point)

Here is a demo of a pure code use of the Flamer: The Flaming Vortex. You can click on the flash to initiate an explosion, and pressing space will change the colour. Have a play:

Flamer Class. The flaming vortex demo

This next demo is an example of throwing a movieclip/sprite at the Flamer class. Don’t laugh, I quite literally spent 10 minutes putting the anims together then threw them at the Flamer. Click on Flash to change colour and object.

Flamer Class Demo. Help, my car is on fire

Lots of fun can be had by throwing different animations at the Flamer. Control some with your mouse/keys. Become a twisted fire starter.

The Flamer class could do with a few more features, but is a pretty good start. The speed is pretty good, I’m happy to receive any improvement recommendations.

I have packed the Flamer class and demos up in a zip if you want to have a play:

DEMO #1: Flaming Vortex
DEMO #2: Burning Movieclips

29
Sep
09

### Flash on the Beach (Part #1): Elevator Pitch… AS3 Genie Effect Transition.

My ‘build a game in three minutes’ session at this year’s excellent Flash on the Beach somehow morphed into building three games in three minutes.

My initial thinking was to code on the fly and put together something simple – I wanted physics and the ability to render a 3D version. It only took a couple of experiments to realise that trying to write AND compile in a strict 3 minutes would be near impossible. I needed some assets and wanted to produce these in the allotted time too.

While cogitating the pitch, I had a lot of game commissions and ideas come through my desk. I clicked that a Game Scratchpad would be a really handy app. Something that I could sketch out a game with – to demonstrate an idea during a brainstorm – at the speed of thought.

More on the Game Sketchpad in Part#2. See the last two minutes of the pitch here (not sure what happened to the first minute):

In the meantime, I got asked by quite a few about the transition effect I used on my slides. To save time I did all of my presentation from within a swf. I wanted a fun quirky transition. The Genie (Ginny) effect is newish – I’d spotted it on wonderfl.net by Clockmaker (inspired by Fladdict). So I grabbed the method and adapted it to allow me to fire it off from a given point – connecting relevant sprites (humorous and tasteless in good measure).

I have packaged the Genie effect here as a Class, with example implementation.

//Usage
import com.swingpants.effect.GenieBmd
var gb:GenieBmd=new GenieBmd(400,300,20)// image width, height, number of segments
gb.startGenie(bmd) // Bitmapdata
gb.fireAtPoint(50,100,3) //x, y, speed (in secs)

Swingpant's AS3 Genie Effect implementation

In part#2 I will explain how the Game Sketchpad works, the component parts, the swf and some source code.

Genie Effect (zip): source

## Flash on the Beach 2010

Swingpants at Flash on the Beach 2010

## Flash on the Beach 2009

Flash on the Beach Speaker