Particle animation, collisions, dynamics. What are these terms, so often thrown around in the 3D world? They are your tools for creating cool special effects in LightWave layout. People often equate the term particle with 3D animations involving small dots, such as fireworks. Although you can create sparklers and animated dust using particles in LightWave, that’s only the beginning. Particles are also used to generate wisps of smoke, fire, snow flurries, and even swarming bees. For many 3D-animation pros, the enhanced particle tools, and the new dynamics capabilities introduced in LightWave 10 (and discussed in detail in this and the next chapter, “Dynamics in Motion”), are enough by themselves to justify the cost of the software. You might hear the term dynamics often in computer graphics. Without getting too technical, the concept of dynamics in LightWave refers to the ability of animated objects to influence one another’s motion and interact naturally. But more than their value, these tools give you control and flexibility over the types of images and animations you can create. That, my friends, is what makes LightWave great!
This chapter takes you into the world of LightWave particle animation. We’ll start with the basics so you can familiarize yourself with how the particle tools function in Layout. From there, we’ll apply surfacing to particles using HyperVoxels to create smoke, fire, and water effects. Then we’ll explore how you can apply dynamics, such as wind and collisions, to the particles. In this chapter, you’ll learn about the following:
• Working with particles in LightWave 10
• Creating surfaces for particles using HyperVoxels
• Using dynamics to change particle motions
Many 3D pros think you need to run out and buy the expensive stand-alone particle creation tools to get decent particle animation. Although dedicated tools have their benefits, you’ll see from the following project that you can achieve exceptional particle animation using nothing but Layout. For most everyday animation projects, the robust, easy-to-use particle engine in LightWave is all you need.
To be clear, particles are not objects, points, splines, or curves. However, if you create an emitter as a “Partigon” you will generate single-point polygons.
In this project, you don’t create anything with the particles; you merely apply them to a scene to see how you can interactively adjust parameters for instant feedback.
The LightWave HyperVoxels tool lets you add smoke-like surfaces to particles, as well as more solid forms for things like water, rocks, and gaseous liquids. HyperVoxels apply to points of an object or to particles.
The first thing you should know is that for particles to “live” in a scene, they need an emitter. You can think of the emitter as a faucet where your particles spill out. The various settings within the particle control panel enable you to adjust how the particles come out, how many, how quickly, and so on. Standard LightWave particle emitters are nonrendering objects you place in your scene, but you can also designate any object as an emitter. A ghostly figure drifting through the air, for instance, might emit a smoke trail consisting of particles with HyperVoxels applied. There aren’t any strict rules about when to use an object as an emitter and when to use a standard emitter; the task at hand usually determines your choice.
Exercise 9.1. Create a Particle Emitter
Figure 9.1. You add a particle emitter from the Add category of the Items tab, just as you would with an object, light, or camera.
Figure 9.2. After an emitter is added, you can apply a name to it and tell LightWave to make it an HV emitter or a Partigon emitter.
What’s the significance of this change? An HV emitter generates points, which aren’t rendered unless HyperVoxels are applied to them (hence the “HV” in the emitter name). HyperVoxels are a type of volumetric effect, which simulate fluid, diffuse materials within a defined physical volume, such as the cone of light generated by a streetlamp, or the confines of a room. HyperVoxels and other volumetric effects are used for rendering phenomena such as smoke and fog, which absorb and diffuse light without reflecting it directly—effects that cannot be approximated easily using traditional polygon-based modeling.
A Partigon emitter, on the other hand, generates single-point polygons, particles that render without HyperVoxels. Partigons can cast and reflect light directly, and you can apply surface characteristics to them. Use Partigons to produce particle systems made up of discrete, tiny objects, such as snow, confetti, or the spray of a sparkler.
Figure 9.3. After a particle emitter is added to Layout, it’s represented by a bounding box, and the FX_Emitter panel appears.
Before you move on, press o to open the General Options tab within the Preferences panel. Make sure that Modified Channels is selected in the Auto Key Create drop-down. This means that when Auto Key is turned on, it will automatically generate keyframes as you make positional or rotational changes at different points in time in Layout.
Figure 9.4. By using Auto Key with Auto Key Create set to Modified Channels, you ensure that your motions are recorded in real time in Layout. Moving the particle emitter around shows the spray of particles.
This effect is great for spraying particles in all directions, as you’d see in a sparkler or in water shaken from a just-bathed dog, but it lacks control. The particles fall out of the emitter without any rhyme or reason. For most other particle systems, such as a stream of smoke or a running faucet, you’ll want your particles to flow in a more controlled fashion. You’ll learn how to make that happen in the next exercise.
It isn’t necessary to always move the particle emitter to see moving particles. The particles can move on their own in a variety of ways. This next section shows you how to create a particle stream to simulate smoke, and with minor modifications it is also good for water fountains, molten lava, gooey chocolate, and more.
Exercise 9.2. Controlling Particle Flow
You’ll notice that the particle emitter (named “Smoke”) is a set size. You can scale it down to fit objects in your scene (Figure 9.5). With smoke, such as you’ll be creating here, the emitter is often a small, concentrated point of origin, such as a pipe or cigar.
Figure 9.5. Adding a particle emitter to the scene gets you started, but first you’ll need to scale it down.
Figure 9.6. Scale the emitter’s generator to a tiny 35 mm cube to begin creating smoke.
Changing the Generator Size in the FX_Emitter panel tells the emitter to be larger or smaller at the point where particles emerge. Changing the actual size of the emitter in Layout scales the emitter itself, not the area of particle generation.
Should you accidentally close the FX_Emitter panel, don’t worry! Select the emitter item in Layout and press p to open the Object Properties panel. Click its Dynamics tab, and then click the item name that begins “FX_Emitter” in the list on that tab. You’ll see all the controls, as in Figure 9.7. You can also find the FX_Emitter panel in the Additional list of plug-ins, on the Utilities tab.
Figure 9.7. In case you accidentally (or intentionally) close the FX_Emitter control panel, you can find the panel again under the Dynamics tab within the Object Properties panel.
Figure 9.8. Increasing the Velocity value for the Y-axis shoots the particles upward.
You can see that the particle preview updates in real time as you adjust FX_Emitter settings. You can click and drag the arrow buttons to the right of a value for true interactivity. Play around with the Velocity values for X and Z to see how the particles are affected, and then revert to a Y velocity of 400 mm and X and Z velocities of 0.
Figure 9.9. Changing the Explosion value makes your particles spray outward, while the Vibration setting adds randomness.
Remember that you can play the animation and make value changes to your particles at the same time. This is the best way to set up particle animations, because you can see exactly what your changes are affecting.
Figure 9.10. Changing the Velocity setting can speed up or slow down your particle stream.
If you watch the particles flow, they seem to be moving evenly at first, but by setting a Velocity value only on the Y-axis, you’re sort of pushing the particles. You want them to appear as if they drift upward. Right now, they come out and just hang in midair. You’ll also notice that with the Velocity value changed, the particle stream is much shorter.
Figure 9.11. Adjusting the Particle Weight and Life Time settings help the particles flow and die a bit more naturally.
If you set the Life Time value to 0, you’re telling the particles to flow infinitely. If you leave the value at 60, the particles would only last 60 frames (2 seconds).
Your LightWave 3D manual gives a good description of the numerous settings and values available to you in the Particle FX_Emitter panel. You should reference this as you work with the tools. These first two exercises have introduced you to particle emitters and the controls available to them. But you can do much more with this system, and you can change how this smoke floats through the air.
Have you ever been visiting a friend and, later that night, found yourself craving a hamburger? So you find the only place open, one of those all-American pub restaurants, and you grab the first available table. You place your order and sure enough, the old lady with long, dirty, gray hair in the booth next to you lights up a cigarette. What happens? The smoke drifts right over to you as you’re trying to eat. While we can’t offer a solution for that situation in this chapter, it is possible to control the direction of smoke in LightWave. Read on to learn how easy it is to determine where your wind blows.
Exercise 9.3. Adding Wind to Particles
Figure 9.12. Add a wind effector to the scene, in the same way that you added a particle emitter earlier.
Figure 9.13. Change the radius of the wind to fit the scene.
Figure 9.14. Rotating the wind effector has a direct effect on the particle stream.
Figure 9.15. Change the Wind Mode setting to Vortex for random emitter control.
Experiment with the various wind modes to see how they affect the particles. If you find a motion value you like, use it. Remember, you can leave the layout animation playback going to see the particles moving while you make changes to the wind.
Figure 9.16. A second wind effector is added to the scene, and its wind mode is set to Path.
Figure 9.17. Move the second wind effector down toward the base of the particle emitter.
Figure 9.18. Create a second position for the wind effector.
Figure 9.19. At frame 160, move the wind effector to the right along the X-axis.
Figure 9.20. Move the wind effector up on the Y-axis for frame 240, and back on the Z-axis.
You see, the point here is that you can work through your particle animation and make changes to key factors such as lifetime, velocity, and others at any point. Your settings are always adjustable.
The path wind feature is very powerful. This exercise introduced you to it, but you can go further by rotating the wind at certain keyframes. What would that do, you ask? How about twisting smoke for things like jet exhaust or tornados? Cool stuff. There’s a video called VisualParticle.mov, available as a free download from www.3dgarage.com, that corresponds to this chapter, showing you more about the different particle settings. Be sure to check it out. For now, let’s move on to learn about collisions.
This next section will show you how to apply collision behavior to your particles. The goal is to make particle systems behave realistically when they encounter obstacles in their paths. Think of smoke hitting a ceiling before it dissipates, or water splashing as it hits the bottom of a sink. The next exercise takes the basic emitter example discussed in the previous exercises and expands it by changing its particle flow with collisions.
Exercise 9.4. Interactive Particles
Figure 9.21. Add a collision effector to the scene.
Figure 9.22. Once a collision effector is added to a scene, it immediately goes to work affecting the particles.
You might have noticed that on the Dynamics tab within the Object Properties panel, you can also add effectors, such as collision. The difference is that adding an effector here will attach it to an object. Since there are no objects in this particular scene, you’ve added a collision from the Items tab instead.
Figure 9.23. New collision planes have a default Radius/Level setting of 1 m.
Setting the Type drop-down to Plane is good for particles hitting a floor or wall, and so on, rather than a box or sphere. If you had, say, a building or a car, you could set Type to Object.
Remember, this is as basic as it gets, but collisions work the same no matter what particle scene you’re setting up. The difference here is that you’re working only with effectors and emitters. You can make any object a collision, and place your particle emitter into any object. Be sure to view the VisualParticle.mov movie file (again, available as a free download from www.3dgarage.com) to see this in action.
Mode is set to Bounce, telling the collision plane to, well, bounce particles that strike it. Alternate settings cause particles to stick to the surface, sink into it, and so on. You’ll see that the Bounce/Bind Power option is set to 100% in the Properties panel. This essentially determines the strength of the collision. For now, this value is fine.
Figure 9.24. Inserting a collision plane in the particle stream does not stop the wind effector that’s pulling the particles, but it deflects the particles’ motion.
Particles can be hard to see in Layout. So when previewing a particle animation, it may be helpful to select the scene’s particle emitter(s) first to highlight them and make them easier to see. While shaping the flow of your particle stream, you may also want to set the emitter’s Life Time value to 0 on the FX_Emitter panel’s Particle tab, to make the emitter generate particles indefinitely, without “timing out.”
As you’ve seen in these few exercises, making particles interact and applying dynamics is not difficult. You’ve easily added an emitter, added wind effectors, and included an animation path. You then made those particles interact with an object by adding a collision dynamic. But there’s one other thing that might be really helpful: surfacing the particles.
It’s possible to exert a ton of control over your particles using things like gravity and collision dynamics, and if you watch the videos for this chapter (available as free downloads from www.3dgarage.com), you’ll see more examples. But you can take even the simple particles created here a step further by setting up a cool surface for them. And once the surfaces are set, you can still go back and make changes to the particle emitter and interactively change the parameters with more vibration, less wind, or faster velocity for cooler effects. For now, these particles are cool, but what good are they? If you render a frame, you’ll see nothing. If there were objects loaded in the scene, you’d see only those render, and you still wouldn’t see the particles. That’s because you created an HV emitter earlier in the chapter, meaning you must apply HyperVoxels to them to make them visible.
Another type of emitter you could add is a Partigon emitter. It works similarly to an HV emitter, except that it generates single-point polygons that will show during a render. These are great for tiny sparks, water sprays, or even stars.
Three surfacing options are available for HyperVoxels: Surface mode, for solid blobby objects; Volume mode, for 3D clouds and smoke; and Sprite mode. Sprites are like 2D surface maps that emulate the effect of a HyperVoxel when it’s applied to a 3D volume. They render much more quickly than true 3D HyperVoxels. These settings have no effect on the particles’ motion in Layout, but only on their appearance. They are fast, great for smoke effects, easy to set up, and always visible in Layout!
Exercise 9.5. Surfacing Particles for Smoke
Figure 9.25. Press Control+F6 to open the Volumetrics tab of the Effects panel, home of the HyperVoxels volumetric control.
You’ll see the name of the HV_Emitter (“Smoke”) grayed out in the Object Name list (Figure 9.26).
Figure 9.26. As soon as you load up HyperVoxels, your particle emitter is visible but inactive in the Object Name list.
The grayed-out controls in the panel’s Geometry tab will become active, and you’ll see that the Particle Size setting has been set for you automatically.
If you want to see how this setting looks, go ahead and make a preview of your particle animation directly in the VIPER window. From the Preview drop-down menu, click Make Preview. After the preview is generated, play buttons will appear. You can stop the preview generation at any time by pressing the Esc key on your keyboard.
Just as you set up textures throughout the book using LightWave’s Surface Editor, you can do the same here in the HyperVoxels panel. You can apply a texture to the HyperVoxel particles just as you would for an object’s surface.
Figure 9.27. Tweak just a few sprite-surface settings and the particles start looking like smoke.
The Orient Slices To Ray setting is designed to keep the slices pointing towards the camera. This helps cut down on render time, allowing the system to calculate for only what the camera sees.
What you’ve done here (Figure 9.28) is basic, but for many types of particle animations, nothing more complex is necessary. With the power of LightWave’s particles, in combination with HyperVoxel surfaces, added textures, and even gradients, the possibilities are endless. Endless how? Read on for another variation on these particles.
Figure 9.28. As you adjust particle-surface settings, remember that VPR will allow you to see instant changes to backdrops as well as particle surfaces.
You can speed up render times slightly by turning off the Volumetric Antialiasing option in the Volumetrics area of the Effects panel (press Control+F6). If you’re using volume-based HyperVoxels, antialiasing will help create a cleaner final render. But for sprites, you can get away with having this setting turned off.
Yes, you read that heading correctly—images on particles. Although it sounds odd, it’s actually a very handy feature for all sorts of animations—falling snow, falling leaves, bubbles—whatever!
Check this out.
Exercise 9.6. Using Images on Particles
Figure 9.29. Loading a 32-bit image from the Image Editor can make your particle systems flow with pictures!
Figure 9.30. A small image is replicated and applied to every particle in the emitter using a HyperVoxel sprite and clips.
That’s it! You now have a stream of floating leaves. HyperVoxel sprites with clips are quite useful. As we just saw, one of the reasons they’re so useful is that you can take tiny images and animate them quickly using particles. You can see them directly in Layout, so you know what’s happening with their size and color, and they always face the camera.
Of course, you can adjust the motion of the particles, perhaps by adding another wind effector at the top of the path to make the particles spread out as they reach their end. You can also change the emitter to a large, long, flat shape to emit sprite clips such as coins, bubbles, puffs of smoke, and so on. Or how about multiple streams, each with an image of a letter? The examples here should get you started with your own particle animations. All you need to do is create a 32-bit image so that the Alpha channel is embedded. You can do this in Adobe Photoshop. Just load up the image you want, place it on a transparent background, and save.
You can do a lot to particles within LightWave. As you’ve seen, you can push them, pull them, make them collide with other objects, and so on. They can look like foam, smoke, or leaves. But what happens when you have everything looking just as you like, and then some pesky particle, following the semi-random rules of particle motion, goes astray and gets in the way of your animation? You don’t have to live with it; you can edit your particles. Read on to learn how.
Exercise 9.7. Editing Particles
Figure 9.31. With the Edit tool in the FX_Emitter properties, you can isolate any particle.
Cloning a particle, copying its motion path, and rotating its path are just some of the other things you can do on the EditFX tab.
This chapter introduced you to some of the coolest features in LightWave’s arsenal. The information in these exercises can easily be applied to projects of your own and ones for your client. You’ll find that particles are so fun to use, you’ll be looking for projects to use them in. Be careful, though—don’t let your client know how easy it is! For now, turn the page and learn about more dynamic effects you can create in LightWave beyond particles.
3.145.180.81