Building Your Own 3D Particle Generator
Dan Ebberts July 18, 2023
0 Comments
In this tutorial, Dan Ebberts explores how you can use expressions in After Effects 5.5 to build a fairly sophisticated 3D particle generator. Our particles will respond to initial velocity, gravity, wind, drag, and much more. Using this particle generator, we'll look at how you might create explosions, smoke, a fire blast, falling snow, and even a liquid-like flow. We'll explore how to make each particle re-usable, which will allow us to simulate fountain-like particle streams. This one is quite advanced.
Explosion MP4
3D Particle Generator .zip
the basics The basic idea is that we will import a graphic representation of a single particle. We'll drag it into our comp and make it 3D. We'll apply our physical simulation expressions to our particle and then duplicate that layer enough times to get a convincing result. We'll set the expressions up so that each particle (layer) will behave differently. We'll be applying expressions to many of the particle's properties, including position, scale, opacity, and rotation.
We'll start off with a simple explosion and develop more complex expressions from there. It will eventually involve some pretty hairy math and some physics (sorry!) but the good news is that you don't necessarily have to understand exactly how the expressions work - you just need to know how to modify them to get them to do what you want. In the first part of the tutorial, what I'll try to do, as much as possible, is to cover the basics of how the expressions work and how you would modify them. Then, towards the end, the stouthearted can follow me through the hairy math and physics.
the strategy We want each of our particles to have a defined life span that will be random within a certain range. Since we'll be applying expressions to multiple properties of the particle, we need some way to communicate information about the particle's life span to all the expressions that need it. We'll do this by performing the life span calculations in an expression control (if you want to learn more about expression controls, see my tutorial Building the World's Greatest Cameraman (COW Admin: coming soon)). We'll then use the expression control as a read-only global variable that can be accessed by all the other expressions applied to our particle.
let's begin! Go ahead and open the project file and then open the explosion basic comp. You'll notice a graphic layer called star flare and a null layer, which both have 3D turned on. We'll be using the position of the null to set the center of the explosion. We'll refer to the null as the particle emitter and later we'll move the null around to impart emitter velocity to the particles. Select the star flare layer and type u to display all the properties that have expressions applied to them. Also type Ctrl Shift t (PC) or Cmd Shift t (Mac) to display the effects applied the layer. You'll see that a point control has been applied and renamed life . You may be wondering why we'd use a point control instead of a slider control to hold the life value. The reason is that later on (when we get to re-usable particles) we're going to need to pass both life and birth times so we need a control that can pass two values. Couldn't we just use two slider controls? No, because the calculations for birth and life have to be done within the same expression to make it work. In the timeline, click the twirly next to Point to reveal the expression applied to the life point control:
lmin = 1.5; //minimum particle life
lmax = 2.5; //maximum particle life
seed_random(1,true);
life=random(lmin,lmax);
birth=0;
[birth,life]
This expression will generate a random life value for our particle that is between 1.5 and 2.5 seconds. This value will be plugged into the second element of our point control variable. The first element ( birth ) is just set to zero since for this first explosion comp all our particles will be born at time zero. The seed_random call just tells After Effects that we want to get the same random value for life every time we run the expression (otherwise the life value would hop around on every frame - which doesn't help us here). If you want to learn more about seed_random , see my tutorial Generating Random Motion (COW Admin: coming soon). If you wanted to change the life span of the particles, you would just change the lmin and lmax values.
Click the twirly next to Position to reveal this expression:
vmin=500; //minimum initial velocity
vmax=700; //maximum initial velocity
birth=effect( life ).param( Point )[0];
life=effect( life ).param( Point )[1];
origin=this_comp.layer( Null 1 ).position.value_at_time(birth);
age=time-birth;
seed_random(1,true);
s=random(vmin,vmax);//initial speed
a=degrees_to_radians(random(180)); //angle from vertical
r=degrees_to_radians(random(360)) //rotation around y axis
x=s*Math.sin(a)*Math.cos(r);
y=-s*Math.cos(a);
z=s*Math.sin(a)*Math.sin(r);
v=[x,y,z];
origin v*time
This is the basic position expression for a zero g explosion. Our particle will launch at a random direction in 3D space from the origin (which is just the position of the null layer) with an initial speed between 500 and 700 units (which roughly equates to pixels per second). The particle will continue at that speed and direction until it dies out. We haven't yet factored in wind, gravity, and drag. I'm sure you noticed the three lines that use the JavaScript trig functions to calculate the x, y, and z components of the particle's velocity vector. This vector is generated from the random values of speed ( s ), launch angle from vertical ( a ) and the rotation relative to the comp's y
Most recent headlines
05/01/2027
Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...
07/10/2026
Dalet, a leading technology and service provider for media-rich organizations, today announced the latest Long-Term Supported (LTS) release of Dalet Flex. Build...
06/09/2026
June 9 2026, 23:00 (PDT) Dolby and MagentaTV Bring Fans Closer to the FIFA Worl...
20/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
20/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
20/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
20/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
20/08/2026
IPC Expands Brazilian Presence with New Channel Partner CCATech
Industry veterans Carlos Abrah o and Bruno Lopes strengthen local support and expand IPCs prese...
20/08/2026
Zixi Enters Mauritius Market Through Strategic Deployment with MTC Jockey Club
Worlds Oldest Horse Racing Club in the Southern Hemisphere Selects Zixis Softwar...
20/08/2026
LA JOLLA, CA-Scripps Research assistant professor Tiantian Liu has received a five-year NIAID DP2 award from the National Institute of Allergy and Infectious Di...
20/08/2026
Audiences reveal appetite for multicultural Australia on-screen 20 August 2026
Dr Georgie McClean, Dr Rebecca Huntley (L-R)
By Dr Georgie McClean and Dr Rebec...
20/08/2026
How Mavis Studio Is Expanding Live Production Teaching at Sussex
Brie Clayton August 19, 2026
0 Comments
Hero image displays a student about to mix be...
20/08/2026
Vertical Unscripted Series Legal Queens Captured with Blackmagic Design
Brie Clayton August 19, 2026
0 Comments
Reality TV veteran Eric Gardner create...
19/08/2026
As the cost of IP nears price parity with traditional SDI, Reynolds argues that ...
19/08/2026
A private 5G bubble was chosen instead of traditional broadcast RF for the race ...
19/08/2026
(L-R) Rafael Manuel and Isabel Sicat attend the Filipi ana premiere during the 2026 Sundance Film Festival at The Ray Theatre on January 23, 2026, in Park Cit...
19/08/2026
Studio owners invited to have their say on rates cuts
The Music Producers Guild (MPG) are inviting UK-based studios to take part in an in-depth survey that ...
19/08/2026
Vintage-inspired desktop interface revealed
Harrison's latest hardware offering sees them head into the world of audio interfaces, delivering a 10-in/12...
19/08/2026
Granular effect remains locked to scale and tempo
Described as your dream granular effect , Minimal Audio's latest creation is capable of turning any s...
19/08/2026
First polyphonic SWAM instrument incoming
Audio Modeling's latest physical-modelling orchestral instrument is just around the corner, and is now availab...
19/08/2026
World Cup Games Generate 84 Billion Minutes Across FOX, Fox Sports 1 and NBCU...
19/08/2026
July brought typical peak-holiday drops in viewership, driven primarily by viewers stepping away from screens and a visible decline in reach across both traditi...
19/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
19/08/2026
Henry joins BCE as the company accelerates its commercial strategy and expands its international presence across the media, broadcast and technology markets. He...
19/08/2026
iWedia, a leading provider of software solutions for connected TV devices, today announced a major milestone in Android platform optimization with the successfu...
19/08/2026
NTP Technology announces that ST 2110-30 audio-over-IP connectivity with AES67 and RAVENNA capabilities is now available for the brand's world-class audio i...
19/08/2026
Net Insight has been selected to provide its Nimbra platform by the service provider Big Blue Marble, formerly ORS Group, as the core media transport solution f...
19/08/2026
LiveU has supported Coventry City FC and several other top-flight UK football clubs through one of their most demanding live production challenges of the year, ...
19/08/2026
Nature Seekers Documentary Shot with Blackmagic URSA Cine 12K LF
Brie Clayton August 18, 2026
0 Comments
Filming endangered turtles required camera...
19/08/2026
Neyrinck Brings D-Control Consoles Back to Life on Apple Silicon with D-Control ...
19/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
19/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
19/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
19/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
19/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
19/08/2026
Riedel Communications today announced that Edith Cowan University (ECU) in Perth, Australia, implemented a comprehensive communications infrastructure that brin...
19/08/2026
QuickLink, a leading provider of award-winning video production and remote guest contribution solutions, will spotlight a major leap forward in remote guest con...
19/08/2026
Integrated platform melds media asset management, playout automation and newsroom workflows
EMAM, PlayBox Neo and SNEWS have officially launched Nuvex, a conne...
19/08/2026
Screen Australia releases the Private Investment Toolkit to strengthen screen in...
19/08/2026
Do Aussies truly value local content? Unpacking Screen Currency 2026 with Deirdr...
19/08/2026
There's an early Christmas gift for Bookish fans, as UKTV confirms the re-commission of the hit U&alibi drama, created by and starring Mark Gatiss. Viewers ...
19/08/2026
Wednesday 19 August 2026
Sky gives sports fans the chance to watch multiple liv...
19/08/2026
On Saturday September 5 Katie Taylor will step into the ring for the fight of her life against Flora Pili in front of 80,000 fans in Croke Park. A legendary fig...
18/08/2026
SportStream 2026, a free three-day virtual event, will take place September 15-17. One registration provides access to all three days of live programming and on...
18/08/2026
BeckTV will introduce BeckFlow to the European market at IBC2026, demonstrated on the Providius stand (10.F53).
BeckFlow is a web-based schematic documentation...
18/08/2026
Boland Communications will introduce a SMPTE ST 2110 input option for its 4K monitors at IBC2026, along with a new 55-inch super-narrow bezel display for video ...
18/08/2026
Dolby Laboratories and the Seattle Seahawks have announced a partnership integrating Dolby OptiView into the Seahawks' live streaming coverage, making the S...
18/08/2026
For BMG Executive Producer of Sports Production, Graham Taylor, producing live s...
18/08/2026
TMRW Sports has appointed Rufus Hack as President of Golf, a newly created role in which he will lead the company's golf businesses including TGL presented ...
Building Your Own 3D Particle Generator 
