Learn about adding a custom 3d particle emitter that emulates dust.
- [Instructor] So far, we've worked with 2D particles. The particles are pretty much a 2D plane. However, we can generate particles in 3D and have them spread out over 3D space. You can also, if you want to, use a 3D camera and 3D lights. For example, let's say I wanted to add particles to this shot of the hostess. Maybe particles that emulate dust motes, pollen, something that's floating between the camera and her. Some close, some farther away. It'd be a great place for a 3D particle system. Let's give that a try.
So this is the color-graded version, and this is saved out again as 6_3. I'm going to start by making a new solid layer to which I can add the particles. Color doesn't matter, but I do want to make it the comp size. Onto this I'm going to add a new particle system, this time Particles, Particle Emitter 3D. I'll play it back. There's a burst of particles, and they look like they're coming towards camera, which they are. Now, I mentioned you can actually use a 3D camera here, so we're going to make a new camera.
Layer, New, Camera. Default lens is okay here. And here we go. Now, if I want to use that camera, I'm going to go back to my effect, and turn on Use Comp Camera. That's the camera view. I can grab my Unified Camera tool, click this right here, and then left mouse button drag to orbit. Right mouse button drag to zoom in, or dolly in. In fact, I can go into the cloud of particles.
Or middle mouse button to scroll. So you can get a different view just by using the actual camera. It can fly into the cloud, away from the cloud, and so on. You can also use actual 3D lights. Now, the effect has built-in lights, and built-in cameras. But I can use a regular 3D light through After Effects, so I'm going to go up to Layer, New, Light. I'm going to change this to a point light, and click OK.
Now, again, to use that, you have to go back to the effect and say Use Comp Lights. And now I can adjust the light, Light Options. For example, if I turn the light down to zero, it loses the light. Now, because this is a 3D light, I can position it. For example, I can go to the Transforms, and move the position. And based on the position, you see that the particles get more or less light.
Some might fade out because the light is not in the correct place. Now, this light exists in 3D space. I can go to the four view and see where it is. In fact, I can move it right there. That might help you position it. If I move the light behind the particles, I lose light completely. And there it is in the 3D view of the camera.
Now the particles themselves are not fully in the 3D space you get with After Effects. However, the effect knows how to use the lights in the cameras if you want. So I'm going to go back to my one view, and move the light so there is some variation in terms of the brightness. I'll go back to the effect. Now, aside from moving the camera around, you can also move the emitter. For example, I can change the position XY so it's just over on the left side of the screen, I can use the target here.
Now they're born from the top left. Now, if I don't see that menu, I can continue to adjust the position of the camera. Now, they're very tiny, so I think what I'll do now is move on to the look of the particles. If I go further down, there is the Particles section we'll roll out. And here I have a Color and a Size. I'm going to increase the size first, and then change the color to the goldish color in the background.
Now one thing that's happening is the particles are starting to disappear. I'll go back up to the top here. Under Emitter, there's a birth rate and the particle speed, and also lifespan. I'm going to make a long lifespan, 100, so they last forever. At least in terms of this timeline. I'm also going to reduce the birthrate so there's fewer of them, I'll try 10. And then slow them down, 50. Now I've lost them completely, I think they're out of frame, so I probably need to adjust my camera one more time.
Get closer to that field. Actually, there's quite a few of them, so maybe I'll reduce the birthrate back down to five. And I like to make them even bigger, so I'll go back down to the size and make them even larger, like they're out of focus. Okay, a little bit more of adjustment in terms of position. We'll just have to experiment with this.
Now, they're being born at the first frame, so I don't have that many of them by the time I get to the end of my timeline. So I'm going to adjust that by going down to the PreRun here, this is underneath the emitter. And I'm going to change PreRun to be a larger number, let's say three seconds here. So they're going to be born three seconds before the timeline starts, so I'll have more of them in the frame.
That's pretty good. Now, they're very opaque, so I'm going to go back to my particles, and aside from size and color, I can also change the opacity. I'll reduce that to a really low number, like 15, like they're very, very much out of focus. Now they're moving in a straight line. They have their initial velocity and they move in a straight line, and that's about it. Let's make them more random. Luckily there's an entire section of forces built into this effect.
There's external forces, and also a built-in fractal field. Fractal field is like a built-in noise, it makes everything more random. I'm going to use that, expand that. And the first thing I'll do is increase the movement noise. Let's try a high number, like 500. And give that a try. And you see they get really wiggly at that point. It might be too much. Now, one thing I can do is adjust the noise frequency, which is the size of the noise that disturbs them. So for example, if I go down to a lower number, like 25, they have more random motion but not quite so extreme.
If I want to make it even more subtle, I can always reduce the movement noise. Let me reduce that a little bit, maybe 250, and perhaps make them a bit faster, I think I went too low on the speed. Let's try 75. And try that. All right, so there are some dust motes.
So you can spend a lot of time experimenting with all of these various settings, particularly the settings that have to do with the speed, the birthrate, lifespan, everything to do with the various forces. Lot of flexibility there. You can also move your 3D camera and adjust your 3D light to get many different looks for your cloud of particles. So there's an example of how 3D particles might be different from 2D particles and where they might be useful.
VFX expert Lee Lanier begins by exploring shared Boris Continuum controls, and then shows how to apply stylistic effects. He explains how to work with the PixelChooser and Boris Lights, and discusses how to color grade and warp footage. He also takes you through using the Boris Chroma Key Studio and working with Mocha Pro for motion tracking, as well as how to add particles and work with 3D text.
- Overview of Boris Continuum
- After Effects preferences
- Applying stylistic effects
- Relighting with Boris Lights
- Adjusting colors
- Changing the time of day
- Warping footage
- Keying green screen
- Motion tracking
- Adding particles
- Working with 3D text