So far we’ve only looked at particle emitters, space warps, and deflectors.
3dsMax particle emitters will generate particles according to predetermined criteria. While they vary from emitter to emitter, the fact is that they’re static implementations of a more diverse idea. The space warps and deflectors have the capacity to alter the behavior of the particles, but not really their look and feel.
That’s why we have access to a powerful tool called Particle Flow. It allows us to customize the rules and procedures that govern the timing, motion, and look of particles.
Particle Flow
Next to the Snow, Blizzard, and super spray particle emitters in the 3dsMax interface, you probably noticed that there’s one I didn’t mention; “PF Source”. It’s full title is read as “particle flow source”, and it acts as the main conduit for creating very extensible particle systems. Go ahead and create one in your scene, and, under the modify panel, click the “Particle View” button from the “Setup” group.
This is the default particle flow window.
I realize that this window is terrifying. Autodesk does not do well in creating a clean and easy interface. However, their engineers are a credit to the industry, so once you get past the cold interaction you’re on top of the heap.
Understanding the terminology of the window will help you understand what each of the 4 quadrants are. The particle flow diagram is made up of events that contain “actions”. In the upper-left quadrant of the window, the default events contain actions like “Birth”, “Position”, and “Speed”. These actions contain parameters similar to the ones you saw in snow and super spray earlier. These parameters are displayed in the upper-right quadrant of the window when you’ve selected an action in the particle flow view.
An age test connected to a material change
The lower right quadrant is called the “depot” and it provides access to all of the possible actions in particle flow. You can drag and drop these actions into the events in the particle flow diagram in order to affect your particles. For example, if we wanted to change the particle material after 30 frames, we’d use an age test, followed by a “Material Static” action. This effect is shown on the right. The resultant particle flow diagram is shown on the left. Finally, the lower-right quadrant shows you a quick description when you select an action from the depot. It’s useful for understanding if the action you’ve selected will actually do what you want it to.
Particles over 10 frames old turn blue.
Whew! That’s a lot to take in, huh? Take your time and don’t get overwhelmed! This will feel like second nature to you in one or two projects. Even better, you’ll be adding a skill to your toolset that will make you a much more valuable artist.
Above you saw how I created a custom event that would have never been possible with ordinary particle understanding. In this way, I can create a wide variety of complicated effects for both still renders and animations. Let’s try making one more complex interaction, and then we’ll call it a day.
The green balls are the onces that bounced.
I’m going to create a deflector in my particle flow that’s going to bounce the balls off of the floor. When the balls bounce, I want them to turn green, and get smaller. I’ll do this by creating a “Collision Test” at the very end of “Event 01″ which will ensure that the collision test takes place after the age test. This way balls that bounce will be green regardless of their age, but blue balls can bounce and turn green. In the upper-right quadrant, when I select the collision test I created, I can set the floor deflector as part of the particle flow system. Once the planar deflector is in place, I can simply drag a “Material Static” and “Shape” actions into the particle flow diagram, and link the event into the flow diagram. It’s important to note that I need to link the age test into the final collision event, or I’ll end up with blue spheres falling through the floor and green sphere’s bouncing back up!
The final particle flow including the "blue" age test, and the "green" collision test.
Key Takeaways
- Particles save you time – The fact is that you shouldn’t have to model large numbers of objects very often, and even reactor can only go so far. You’d be surprised how applicable particles are in working with 3dsMax. Any effects that need a large number of objects can be replicated using the standard particle tools available in the program.
- Deflectors are for control – Use deflectors to control your particles. Think of them as the banisters on the side of the freeway. Your particles need to know where they aren’t allowed to go. This means anything from preventing penetration of walls and characters, to handling complex interactions like a car plowing through gunfire.
- Forces are for flow – Use forces to direct your particles. This is different from deflectors because you’re providing the impetus for your particles do what they were intended to do. Think of forces as the freeway itself- it tells your particles where they’re expected to go.
- Particle Flow is amazing – Particle flow is, indeed, amazing. It gives you the ultimate level of control over particles in 3dsMax. You can set up infinitely complex rules that govern how your particles look, where your particles go, and how they’re presented when rendered. You can link age to material like we did in the example above, but don’t let that limit your imagination! Make particle flow rate variable over time, or try making your particles glow using mental ray materials! The sky’s the limit.
I hope you’ve enjoyed this particles walkthrough. If you have any questions or comments, feel free to leave them on this post, or e-mail me at MrBluesummers@MrBluesummers.com As always, take care. Happy modeling.
