🎬 Particle VFX

A particle system models a fuzzy phenomenon — fire, smoke, sparks, explosions — as a large collection of tiny independent points. Each particle has its own position, velocity, lifetime and colour, and is updated every frame by simple rules. Rendering many of them together produces effects that would be hard to describe with solid geometry. This technique has been a staple of film and game VFX since the early 1980s.

Fire particles carry a temperature in kelvin and are coloured by a blackbody-inspired ramp. Around 800K the particle appears deep red; as the value climbs towards 1200K it brightens through orange and yellow to near-white. Each fire particle also cools over its lifetime, so it visibly fades from white-hot at the base to red at the tips, just like a real flame.

Emission Rate sets how many particles are spawned per second (10–300), controlling the density of the effect. Gravity (0–30) pulls sparks and debris downward, so higher values make them fall faster. Turbulence (0–3) scales the noise field that jitters particle velocities, adding chaotic, wind-blown motion to fire and magic trails.

It is physically inspired rather than exact. The exponential cooling T(t)=T₀·e^(−t/τ) and the temperature-to-colour mapping reflect real thermodynamics and blackbody radiation, and gravity behaves plausibly. However, values are tuned for a good visual result, not real units, and the turbulence uses a fast hash function rather than a true fluid solver, so it is an artistic approximation of real combustion.

The simulation draws particles with a "lighter" composite mode, meaning overlapping particle colours are added together rather than painted over one another. Where many bright particles stack up, the colours sum towards white, producing the intense hot core seen in real flames and explosions. A faint translucent fill each frame leaves short fading trails, reinforcing the sense of motion and afterglow.