Ever seen a movie that had sparks flying out of control panels? Or maybe you’ve always wanted to have smoke coming out of your character’s ears when he’s mad? Those are particle effects, and you’ll find that they’re a breeze in 3dsMax when you use the right tools.
Particles are what artists use when they need a lot of objects, but don’t want to model or animate them by hand. Particle systems create, animate, and destroy objects according to a set of rules. These rules can be very basic, like “create 10 spheres per frame, starting at frame 0″. These are known as non-event-driven particle systems. 3dsMax particle systems can also be quite complex! Take, for example, the motion of soap bubbles in the air. They float quasi-randomly and if they touch, they stick together. If they touch another object, they’ll pop, and sometimes they just pop for no reason at all. This might be considered an event-driven particle system since the bubbles are subject to a variety of possible events.
We won’t be getting into the very gritty how-to details of particles during this tutorial. I’d like spend most of this guide walking you through the concepts involved in using basic particle emitters because 90% of the time they’ll do the job just fine. Toward the end of the tutorial I’ll introduce you to the particle flow and particle view tools that 3dsMax has to offer. This last segment will show you just how complicated your particles can be!
But don’t worry. At the end of the day, particles are meant to make your life easier, not harder. This walkthrough shouldn’t take more than about 30 minutes to complete, and when you’re done you’ll have a good exposure to the options available to you.
Non-Event-Driven Particle Systems
Let’s have a look at the simplest particle systems. I’ve gone ahead and created a simple scene to help illustrate the effects of my changes to the particle system. You can play with settings that correspond to what you’re learning about, or just skim the tutorial to get an idea of how particles work.
Spray and Super Spray
Both event and non-event-driven particle emitters
Spray and super spray are basically the same thing. Super spray includes all the functionality of the basic spray, so most of the time you’ll opt for this particle system. I’m going to dive into some examples of using super spray since it’s a great starting place for getting acquainted with 3dsMax particles. You can find the super-spray object under the create panel, under the objects category, and in the “Particle Systems” group.
Once you’ve selected the “Super Spray” object, you can click and drag on your screen to create a particle system. The size of the emitter will not determine how large the emitter is, but the position and orientation will determine the origin and direction of your new particle spray.
Now if you’re working from the default file, and still on time t=0, then you probably don’t see any particles at all. This is because particles are time based; they don’t happen instantly. Go ahead and scrub the time-slider at the bottom of your screen and you’ll see particles being emitted from your super spray object. You can also hit the “>” key a few times and you’ll step along the animation by a few keyframes.
Let’s take a closer look at the super spray and it’s parameters. It may seem a little tedious since there are so many rollouts, but remember that a lot of the foundations we lay out here will help you when we’re looking at the other particle emitters and event-driven particle systems later on. I’ll try to keep things concise, but I’ve gone ahead and included the full rollouts on the left side. It shows every parameter in the super spray object.
Basic Parameters
A semi-planar emission.
Basic Parameters
The basic parameters rollout will allow you to make changes to the direction that the particles flow, as well as how they’re displayed in the 3dsMax viewport. The off axis and spread parameters control how the particles are spread out over a single plane. Imagine a Japanese fan spreading out. It starts off as a single bar, and then fans out along a plane. Both of these “Off axis/plane” controls handle the rotation of the emitter, while the “Spread” controls handle the range over which the particles may be emitted.
The off plane and spread parameters, control how that 2-dimensional fan of particles is spread out over all 3 dimensions. If all four of these parameters is set to their maximal values, we’d expect to see a perfect circular particle emission. Such an effect would be useful for explosions or 360-degree emissions like meteors.
Finally, we have control over how the particles are displayed in the 3dsMax viewport. It’s generally recommended that you keep as few particles displayed as possible. 10% can sometimes be too high for particles like dust, clouds, and steam where you only need to see a very small fraction of the particles to understand their overall flow. Each particle that the computer has to draw is another drag on performance- even if they’re just ticks.
Particle Generation
Particle Generation
Particle generation parameters are geared around how the particles behave and act during and after creation. Oddly, this includes parameters like speed, sizing, and timing, but not parameters like rotation and shape. Think this is wierd? Me too.
The first two parameters, “Use Rate” and “Use T0tal” cover the speed at which particles are generated. A rate is how many new particles should be created every frame, while a total is how many particles should be generated between when the emitter starts and when it stops. Thus 200 total over 50 frames (4 particles per frame) will generate fewer particles than a rate value of 5. This works in conjunction with particle timing, which controls aspects of the particles like how long they should be generated for, how long they should live, and the variability of that lifespan. I say this because you’ll often find that fewer, older, larger particles can often do the job of more, faster, smaller particles.
It’s sad, but particles die too. If they didn’t, your scene would be overrun with particles that drag performance into the ground. Remember to set a tight life for your particles to keep your render times down, and you’ll be fine. The variability aspect gives you some randomness for your particle emission, and works great for things like smoke and sparks.
Finally, particle size controls how big the particles are, how variable their sizing should be, and how they should grow and fade over time. If your particle’s life is set for 30 (that’s 30 frames) and they grow for 10 (frames) and fade for 10 (frames), then your particles are at maximum size for only 10 frames. If you set the grow and fade to only 2, then you have particles appearing almost instantly at full size and vanishing just as quickly.
As a brief note, the uniqueness parameter is for randomizing multiple emitters. For example, if you have 3 smoke stacks on a factory, you’ll want to set different seed values for each smoke stack to keep them looking different.
Particle Type
Particle Type
The particle type rollout handles parameters that affect the particle’s type and appearance.
There are three general particle types; Standard Particles, MetaParticles, and Instanced Geometry. The first is simply the creation of a massive number of primitive objects. Some of these standard particles are obvious like sphere and cube. “Facing” creates planes that face the camera on every frame, which works well for smoke and cartoon snow. The “Special” is two squares intersecting at 90 degrees, while the “SixPoint” is made of two rotated triangles to form a star. The constant is a facing square that is always the same size regardless of distance from the camera. The “Tetra” is a 3d pyramid shape made of four triangles. Notice that there are only three 3d shapes on this list; the rest are planar!
Metaparticles are similar to metaballs which are common across many 3d graphics programs. 3dsMax uses them to approximate fluid dynamics and other “goopy” effects. The special traits here are tension, variation, and evaluation. Tension controls how close the metaballs need to be to each other in order to deform and “goop” together. A low tension value means a high likelihood that particles will merge in flight. Variation controls the variance on this value, while evaluation handles the quality of the effect. A low evaluation coarseness means a very crisp result, while a high value means a very rough result.
A metaball particle emitter. Fun!
The “One Connected Blob” parameter is a lot of fun. It culls stray particles from the render and keeps only the largest connected blob of the particle emitter. Useful for an “oh no; it’s growing!” type effect (seen here).
Finally, the instanced geometry object type is relatively self-explanatory. It allows the emitter to blow out copies of an object you’ve already created. This works well for leaves, tennis balls, lawn mowers, or whatever else you can think of. Nothing’s more fun than raining televisions through your 3dsMax scene.
You’re able to control the sub-animation of the object (for example if those lawn mowers are engaged) as well as the material source. You can chose to obtain the instanced geometry’s material from the icon (i.e. you can apply a material to the emitter itself) or from the original geometry source.
