Life & Style tutorial: Handling particles in After Effects

If your budget doesn’t stretch to pricey plug-in particle filters, use After Effects’ internal tools.

After Effects CS3 includes built-in particle filters you can use in your projects. Although they are not as powerful as some of the specialist 3D particle filters (like Trapcode’s amazing Particular plug-in), you can use them to achieve fairly convincing animations of natural phenomena such as fire, smoke, rain and dust.

All you need is patience and a natural affinity for tweaking sliders. In this tutorial, Angie Taylor shows you how to create fire, smoke effects and 3D rocks, all using After Effects’ built-in 3D particle filters, to create part of the title sequence for Taylor’s forthcoming animation Hellwoman, a spoof of the movie Hellboy,. For the tutorial, you’ll use two filters that allow you to animate particles in 3D space: CC Particle World, and Shatter. Before you start, watch the full clip, so that you know what you’ll be creating. Open Hellwoman_AngieTaylor_Start.aet, and double-click the movie in the Project panel.

01. We’ll start by creating the fire effect. In the Project panel, open 01_Fire comp Start. In here is a solid layer with the CC Particle World effect applied. Press 0 on the number pad to RAM-preview the composition. The default behaviour is for the filter to emit lines from the centre of the screen. You’ll also see a 3D ground-plane guide representing the floor of the 3D world. It’s hard to imagine how we can make fire from this, but just wait and see what can be done with a bit of tweaking.

02. We’ll start by opening the Physics section: these settings determine how the particles move. Change the following settings: Gravity = 0.35; Animation = Viscous; Velocity = 0.9; Resistance = 1; Extra = 3.31. RAM preview the effect and notice how the particles now move upwards rather than in the fireworks form of before.

03. Open the Particle section and change the following settings; Particle Type = Faded Sphere; Birth Size = 0.661; Death Size = 0.714; Size Variation = 100%; Max Opacity = 20%; Birth Color = 255, 217, 84; Death Color = 201, 4, 4; Transfer Mode = Add. RAM preview and you should now see more fire-like particles moving upwards. But we need more particles to build up the flames.

04. Increase the Birth Rate to 10 and Longevity to 0.90. Open the Producer section, change the Z Position to -0.40 and the Y position to 0.15 to move the flames up and nearer the viewer. In the Grid menu, choose None to hide the 3D grid and RAM preview to watch your ball of flames. At the top of the Effect Control panel, click the Options hyperlink to open the additional options.

05. Click on Opacity Map and change the Opacity graph by dragging across the existing curve to draw a new curve. Click the Soften button to soften the curve. Click OK to leave the dialog box.

06. To add a finishing touch, add the Turbulent Displace effect to the layer and change the following settings: Displacement = Turbulent Smoother; Amount - 40; Size = 10; Offset (Turbulence) = 517, 460; Pinning = Pin Bottom. Once you have changed these settings, animate the Evolution value from 0 at the beginning of the comp to 5 revolutions at the end of the comp. Turbulent displace will add a little more random movement to the flames, adding to the realism.

07. Open the 04_Smoke start comp. In the CC Particle World Effect Controls enter the following values; Grid = Off; Birth Rate = 100; Longevity = 2; Position Z = 0.3; Radius X = 0.5; Animation = Cone Axis; Velocity = 0.5; Gravity = -0.01; Extra = 1.2; Particle Type = Faded Sphere; Birth Size = 1.69; Death Size = 1.762; Size Variation = 100; Max opacity = 1.5; Transfer Mode = Add, with a white Birth Colour and yellow-grey Death Colour.

08. In the Project panel you’ll see two other fire movies, RAM preview these to see the different fire effects that can be achieved with CC Particle world. These examples have custom Layer textures; we’ll look at working with custom layer maps soon.

09. Open 05_End comp. Start to see a wall of Rock, painted with Corel Painter. Another option when working with particles is to split an existing layer into particles. After Effects has its own filter for doing just this, named Shatter. Select the ‘Painted Shatter Rocks’ layer and hit F3 to open the Effect Controls.

10. Preview the composition and notice that it explodes the layer into brick shapes – currently represented in wireframe mode. In the Effect Control panel, change the View menu to Rendered and preview again to see the bricks rendered with the rock layer texture. Open the Shape section, from the Pattern menu, choose Custom and from the Custom Shatter Map menu choose 3. Rocks Shatter Map. This is a custom shatter map that I created in Adobe Photoshop and imported into the comp. Change the Extrusion Depth to 0.5, and the Side Mode and Back mode menus to Tinted Layer. Open the Physics section and change the Rotation Speed to 0.5 to make the pieces of rock spin as they explode. Switch on the other layers in the comp. Notice the Custom Shatter Map – it uses pure CMYK and RGB colours.

11. Open the Textures section, click on the Color Swatch to change the colour to a warm, mid-grey colours (black and white can also be used) to denote the pieces. Once you have looked at this layer, switch off its video switch and RAM preview the comp. You should now see the Hellwoman character and some 3D text appearing from behind the rocks. I’ve also added an animated sky, which was created using the Fractal Noise filter. All we need now is to composite our fire and smoke in here.

12. Drag the finished Fire comp into the Comp so that it’s above the two Fire layers, drag the finished Smoke comp on top of these and change its blending mode to Lighten. Particle World and Shatter both produce particles that animate in 3D, so you could place a new camera layer into your comp and animate around the flames in 3D space. Particle World lets you do this automatically, if using Shatter, check the Comp Camera checkbox to enable this feature.

Who: Angie Taylor produces animations, visual effects and graphics for television, film, video and the Web. Her work regularly appears on British and European TV. She is the author of Creative After Effects 7, and she regularly tours with Adobe and Apple giving demonstrations and seminars.
Software: Adobe After Effects CS3
Time to complete: 45 minutes – 1 hour
On the CD: All files for this tutorial can be downloaded here or are available on the cover CD.


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