particle-system

Give each particle position, velocity, and life state, then every frame accumulate forces into acceleration, integrate velocity and position with semi-implicit Euler scaled by dt, age the particle, and respawn it when dead. Use canvas 2D for hundreds of particles and Three.js Points for thousands.

Spawn a burst of particles at a point with randomized angle and speed, then apply gravity and air drag each frame. Confetti reads as paper because of rotating flat rectangles with a height squash from Math.abs(Math.cos(rot)), not round dots.

Canvas 2D handles hundreds of particles comfortably with CPU updates. For thousands or more, push positions into a Three.js BufferGeometry rendered as Points and animate in the vertex shader, which keeps 80k+ particles at 60fps with no CPU updates.

Use a uniform spatial grid: bin particles into cells sized to the link radius and only compare each particle against its own and the 8 neighboring cells. This makes the constellation effect O(n) for evenly distributed particles and scales to hundreds of nodes.

Vanishing particles usually indicate NaN positions from an unclamped dt or a stalled tab, while bunching at the origin means the RNG was not wired into spawn positions. Clamp dt to 1/30, seed the PRNG, and check the console for parse or init errors if the canvas is blank.

Curl noise is a divergence-free velocity field computed from the curl of a noise potential via finite differences. Unlike a plain angle-based flow field, it has no sources or sinks, so particles swirl like smoke or water instead of piling up.