Particle universe guide

Every control

Every control in the panel, top to bottom. Camera and Actions start closed; tap a title to open it.

Load and save

They stay at the top while the panel scrolls. Your pictures stay on this device for every lab tool until you press × on a tile. Reset puts the controls back: every setting goes back to how the page opened, and the cloud returns to the Image formation, face on. The picture you chose stays.

Image AButton: Your picture, made into the cloud. Press it to open one from your device, or drop one on the frame; two at once fill A and B. It is kept on this device, never uploaded, and every lab tool that takes a picture opens with it until you press × on its corner. It replaces the cloud with a new one made from that picture, and keeps the formation you picked. Big pictures are read at up to 400 pixels on their long side.
SwapButton: Changes which tile Particle universe uses, so a picture you added as B in another tool can be used here. When the other tile is empty, the sample comes back.
Image BButton: A second kept picture. Particle universe makes a cloud from one picture at a time: the tile it is not using is dimmed and says Not used here, and pressing it only says so.
Save PNGButton: Saves the frame as you see it as particles.png. See PNG.
Record videoButton: Starts a video of the frame; the button then reads Stop recording. Press it again to save the video. See MediaRecorder.
CopyButton: Copies the frame as a PNG to the clipboard, where the browser allows it. See clipboard.

Image

Here, a small preview shows your picture, and a line gives its size and how many points it made, such as 600x600 | 50,176 particles. The number is close to Particle count, not exactly it, because the points follow a grid over the picture.

Formation

The shape the points fly to, how fast they get there, how many there are, and how they are coloured and drawn.

Image · Sphere · Galaxy · DNA helix · Cube · ScatterPick one: Each point is given a place in the new shape and pulled there. See formation and morph target.

Image: The picture itself, laid flat and 4 units tall. The camera turns face on and stops turning. See image formation.

Sphere: Points spread evenly over the surface of a ball.

Galaxy: Three spiral arms on a flat disc. From the opening camera you see it edge on; drag down to look at it from above. See galaxy formation.

DNA helix: Two strands wound four times around an upright axis, with a little jitter. See helix.

Cube: Points spread at random over the six faces of a cube.

Scatter: Points spread at random through a box around the middle.
TransitionSlider · 0.01 to 0.15 · starts at 0.04: How hard each point is pulled toward its place. Higher arrives sooner and swings past more; lower drifts in slowly. See spring.
Particle countSlider · 10000 to 100000 · starts at 50000: How many points to make from the picture, from 10K to 100K. When you let go, the cloud is made again: the points start flat on the picture and fly back to the formation. On phones and touch screens it opens at 30K and stops there.
Color modePick one · Image · Velocity · Position · Rainbow: Where each point's colour comes from.

Image: The pixel it was taken from.

Velocity: Its speed: blue at rest, turning orange as it moves fast. See colour by velocity.

Position: Where it sits: red rises to the right, green rises upward, blue rises toward the front. See colour by position.

Rainbow: Its place in the picture, run through every hue, and the colours slowly cycle.
RenderPick one · Flat · Glow: How each point is drawn.

Flat: A solid round dot. Near dots hide the ones behind them.

Glow: A soft dot with a halo, added on top of the dots behind it, so crowded parts turn white. See additive blending and glow sprite.

Physics

What moves the points besides the pull of the formation.

Pointer forceSlider · 0 to 5 · starts at 2: How hard the pointer pushes the points near it. At 0 the pointer does nothing. See mouse force.
Pointer radiusSlider · 0.3 to 4 · starts at 1.5: How far from the pointer the push reaches, in the same units as the shapes; the sphere is 5 across. See mouse radius.
TurbulenceSlider · 0 to 2 · starts at 0: A wavering nudge on every point, so the shape shimmers and breaks up. At 0 it is off. See turbulence.
FrictionSlider · 0.85 to 0.99 · starts at 0.94: How much of its speed each point keeps from one frame to the next. Higher glides longer and wobbles more before it settles; lower stops sooner. See friction and damping.
RepelOn or off · starts on: Sets which way the pointer's push goes. Ticked, as the page opens, the pointer pushes points away; cleared, it pulls them in toward it. See repel.

Appearance

Point sizeSlider · 1 to 8 · starts at 2.5: How big each dot is drawn. Dots nearer the camera are drawn bigger still, so even size 1 makes large dots. See point size and size attenuation.
GlowSlider · 0 to 1 · starts at 0.5: How strong the halo is around each dot. It changes only the Glow render.
TrailSlider · 0 to 0.3 · starts at 0.05: Leaves fading streaks behind moving points: each frame, the one before is darkened toward the ground instead of wiped away. Higher leaves longer streaks; at 0 every frame starts clean. See trail.

Camera

Dragging on the frame turns the camera around the cloud, and the scroll wheel or a two-finger pinch moves it closer or further. See orbit camera.

Auto-rotateOn or off · starts on: Turns the cloud slowly on its own, in every formation but Image. It opens ticked; clear it and the cloud holds still. See auto-rotate.
Rotate speedSlider · 0.05 to 1 · starts at 0.15: How fast the cloud turns on its own.
DistanceSlider · 3 to 15 · starts at 6: How far the camera sits from the middle. The camera glides there as you move it, in every formation; the scroll wheel and pinch move it too.

Actions

ExplodeButton: Throws every point in a random direction at once. The pull of the formation then brings them back. See explode.
ReformButton: Sends the points back to the flat picture, face on, and selects Image under Formation. See reform.

Reset

ResetButton: Puts every setting back to how the page opened, including Trail at 0.05 and Repel and Auto-rotate ticked, and sends the cloud back to the flat picture, face on. The picture stays.