This experiment simulates 1,200 point sprites moving through a simple flow field. Each frame, every particle keeps its velocity and gets nudged by a few forces:
- A tangential spiral force that makes particles orbit
- A radial pull toward the core
- A convergence force that steers particles back toward the main flow radius
- Procedural turbulence from a lightweight 3D sine-noise function
After the forces are applied, velocity is damped slightly, then integrated into position. If a particle drifts too far out, it is respawned near its original seed position with zero velocity. That keeps density stable and prevents the cloud from thinning over time.
Colour is recalculated every frame from distance to the center. Hue blends from inner to mid to outer bands, then lightness is scaled by a global brightness control, boosted by speed, and modulated by a per-particle age pulse. The result is a soft nebula look where faster particles read as brighter without needing scene lights.
Rendering uses textured THREE.PointsMaterial sprites with optional additive blending and exponential fog. Additive blend gives a glow-heavy look, normal blend gives more structure, and fog density controls how quickly depth fades into the background.
