TRAPCODE: Particular - Part 1

Setting up 3D Lights for particle emission

This tutorial is part of a series outlining several features of Trapcode's new plugin, Particular. If you have been entrenched in too much After Effects work, or are living under a rock, you may not have heard about Trapcode's newest plugin addition, announced at April's NAB. Many people preordered he plugin at the show, and more tapped into it when it released on May 10. If you don't already have it, you'll need the plugin, or at least the demo to complete this tutorial. You will also need After Effects 6.0 or greater. If you are downloading the demo version, be sure to download the other demos as well. Trapcode's LUX is a useful tool to have when using 3D lights in After Effects, for any purpose. You can download the demo of any of the Trapcode plugins by clicking here.

In addition to the extensive help file included within the Particular plugin, Trapcode's solo master, Peder Norrby has included 2 separate tutorial videos on the Trapcode website. [To find the internal help see the HELP button under the Options link at the top of the Effects Control window.] Look for more Particular tutorials on the Trapcode site.

Step 1: Setting up the comp

To start this tutorial for Particular, create a new composition within After Effects 6.x. I'm going to use a small window to produce images for this tutorial, 320x240 at 15 frames per second.

Next add a spot light. Add a new light, using "Emitter" as a name. When Particular emits particles from lights, it looks for a specific naming convention. You can change the target name within Options if you'd like. For the sake of clarity, I'll leave it as "Emitter"; this is the default name in the plugin.

Next add a new solid (any color), the size of your comp.

Finally, add a 35mm Camera to your scene.

Your composition's layers should look something like this:

Step 2: Creating a Motion Path

Select the Solid Layer (Black Solid). Using the eliptical mask tool, create a circular mask Select the eliptical mask tool (Q). Click in the center of the solid layer then begin to drag. If you hold the CMD key down, you can draw a mask emanating from the click point. If you hold the SHIFT key down, you will create a circle rather than an elipse. Holding both CMD-SHIFT while dragging will create a circle emanating from the click point.

Next, we'll copy this circle into the position path of the light. Select the Black solid's Mask shape (M), Copy (cmd-c). Then select the Position parameter for the Emitter/light (P) and paste (cmd-v). This will create keyframes based on the position and curves of the spline. The first and last keyframe are linear, with the middle keyframes set to rove. Simply dragging the last keyframe will scale the entire animation sequence from first to last keyframe. Click and drag the last keyframe to the end of your timeline. Hold SHIFT to snap keyframes. [Note: If you move any of the roving keyframes, they will become hard keyframes, based on your default keyframe characteristic.]

One last part of this setup is to align the light correctly to the path.

Initially, the light itself is positioned along the circular path. However, the target "point of interest" is still at 50/50% of the composition. The first correction is to use a simple function built into After Effects: Auto Orient. You can find it in Layers->Transform->Auto-Orientation. Select "Orient Along Path". This will deactivate the point of interest, forcing the light to point forward, parallel to the path at the same point in time (no bent light here!).

Finally, the light's rotational orientation must be adjusted so the cone faces away from the direction of the light. Choose the Emitter/light rotation, and set the Y-orientation to 180 degrees.

Now the animation is prepared for adding particles with Trapcode Particular.

Step 3: Adding Particular

We'll simply reuse the solid (Black Solid) that we used to create the motion path. To reuse this, delete the mask shape from the layer by selecting the layer, selecting the mask shape, then clicking the delete key.

With this solid layer selected, choose Trapcode Particular from the Effects plugins.

Initially, Particular will default to creating particles from a point emitter located at 50/50% of the composition.

The Preview menu is the first function within the plugin. To find out everything about the Preview portion, simply check out the introduction on the Trapcode website.

The second portion of the plugin, Emitter is made of up several options itself. (see image below)

The first section under Emitter is Particles per second. This is pretty self-explanatory. Increasing the number of particles per second will change the number of particles emitted during each second of your animation. You can create tens of thousands of particles if you'd like, but you'll notice an increase in render time as you add to this number. I haven't noticed a severe penalty until I go over 10,000 particles per second. Fortunately, most of the animations I create with Particular only require a fraction of that, allowing me to stay with a very, very fast render. I'll set the value to 320 particles per second.

The second subsection contains definitions for the type of emitter. Here, we'll select "Light". The other versions are defined on the Trapcode website and within help.

You'll note that the position controls are now grey'd out. The position of the emitter is based on the 3D position that our light possesses.

The next active parameter is Direction. In this tutorial, we'll use "Directional". You can find definitions of the other direction characteristics within the help menu.

The next active parameter is actually a set of variables governing velocity. They are "Velocity", "Velocity Random", and "Velocity from Motion". The velocity is the speed at which the particles leave the emitter's source. Using a random value changes the speed difference each particle may have, based on the value velocity. Finally, the velocity derived from motion uses the animation of the emitter to create the speed of the particles.

I'll set the velocity parameters using the following values:

The last active parameters in the Emitter section set the emitter's X, Y, and Z size. For now, we'll leave the sizes set to their default values of 50, 50, 50. For a wide, flat stroke, try chaning the X value to 150.

You should have something like this in your Emitter settings:

Step 4: Light editing and preview

The particles are, by default, now based on the light, not only in position, but in color and light options!

Open the options in the Emitter/light to see some immediate changes you can make.

Now you can preview the potential of those particles by using Particular's Preview window. Clicking on the window allows you to rotate around the animation while holding the SHIFT key while you click allows you to change the position of the emitter point in the preview window (this doesn't change the keyframes you've set in the AE layer). If you want to animate your render, you'll have to create keyframes within the comp itself, most likely on the camera position track.

The next installment will focus on more parameters available to our particle emitting light.

To see other plugins available from Trapcode, check their website for news, updates to software, galleries and tutorials.

Ko Maruyama is a Los Angeles based freelance animator and host on the After Effects forum. When not setting up animations to render, you can find him answering questions in the DMN Forums and lurking in the new Mac___Pro page forums. Check out my favorite new additions to the CreativeMac family: MacAnimationPro, MacDesignPro, and MacDVDPro.