Particle Effects
Particle Tool and Fields

Particles are extremely useful for creating effects in your scenes such as water, dust, exhaust, fire, and infinite more possibilities. However, it's important that you know the different methods of creating particles in order to use them the most effectively. It's also important to understand Fields, and how they relate to the realism of your particles. You'll almost always have some kind of Field effect alongside your particles.

So, for this lesson, I'm going to go over a few of the Particle creation commands, as well as the more basic Fields and what they do.

First, let's take a look at the Particles menu in Dynamics mode (Fig 1). So, here we have these items:

  • Particle Tool w/options
  • Create Emmitter w/options
  • Emit from Object w/options

There are many more items in this menu, but we aren't going to go over them in this lesson. Today, we're going to focus on the Particle Tool. Create Emitter and Emit from Obj will be covered in later lessons... Promise! ;)

Figure 1
The Particle Tool allows you to create particles by placing them with your cursor. So, let's take a look at the Particle Tool options (Fig 2). Figure 2
Particle Name simply allows you to name your particle object before you create it. You don't necessarily have to put anything here. If you don't, it'll use a default name such as particle2.

Conserve refers to conserving momentum. We'll go over that in a little bit.

Number of Particles indicates how many particles will be created with each Left-button mouse click. With the default at 1, if you click out in your scene, you'll get Fig 3. A small red dot. You can continue clicking, placing more individual particles until you press Enter. At that point, the dots will convert to a finalized particle object which can be used in your scene. Figure 3
If you increase the Number of Particles, to say 7, you'll see a new option become available. The Maximum Radius slider allows you to control how spread out the 7 particles will be from each other. So, with a number of 7 and a radius of 5, with each click you get Fig 4. If you decide that you don't like the placement of one or more of the particles, simply press the Insert key on your keyboard and Middle-mouse drag the faulty particle to a more favorable position. You can only do this before you press Enter to finalize the particle creation. Figure 4
Now, we've been clicking and placing small groups of particles around, but if you check the Sketch Particles option, you'll get a new slider available as well as a new effect. Sketch Particles allows you to click and drag a stream of particles (using your number and radius options) through your scene. The Sketch Interval slider dictates how thick the effect will be. The lower the slider, the more dense your particle stream will become. (Fig 5) Figure 5
Next is Create Particle Grid. You'll notice that when you select this, Maya no longer cares about the number of particles, the maximum radius, or whether or not you want to sketch them. However, it does give you a few other options. Particle Spacing and Placement. The lower Particle Spacing is, the more dense your grid. (Fig 6) To create a grid, go to an Orthographic view and place a particle where you want the upper left corner to be, then place a particle in the lower right corner. Press Enter, and the area between will fill with particles using the options you specify for spacing.

Placement simply allows you to choose to position your grid with your mouse cursor, or by entering specific coordinates in the slider field below. I usually just use my mouse.

Figure 6
There is one cool trick that allows you to create a CUBE of particles, rather than just a flat grid. After placing your two reference points, go into another view, press the Insert key, and move one of them up or down. Now, when you hit Enter, it'll fill the 3D space between both points with particles and not just the 2D plane they were originally drawn on. (Fig 7) Figure 7
Now, that we've gone over the Particle Tool, let's go over Fields and what they do. One thing that helps is to create a patch of particles and then see how the fields affect them. This eliminates the guess-work involved. So, first we have my scene, which is a group of particles (Fig 8) Figure 8
First on the list of Fields is Air. Select the particle object and then selece Air from the list. Place the Air icon in the midst of your particles and press play. As you can see (Fig 9), under the default settings, the affected area rises. Figure 9
Let's undo and try the next one: Drag. To demonstrate the Drag, take a look at Fig 10. I've created a Drag Field and have made it affect a certain area. Then, I've put an emitter above it that is shooting particles in all directions. If you notice, the particles that enter the Drag's area of influence come to a halt and begin to pile up. The Drag Field causes objects with Dynamic motion to slow down or stop depending on the options used. Because I agree with the saying that a picture is worth a 1000 words, let's let the images do the describing for the rest of the Fields... Figure 10
Figure 11Figure 12Figure 13Figure 14Figure 15Figure 16

I hope this tutorial was of some use to you. Eventually, I'm going to attempt to have more concerning particle effects, as it seems to be one of the largest areas of Maya not touched on in depth in most classes.

Michael McKinley