Crowd → Fluid

Build your venue. Place doors, objects, walls. Watch the crowd find its way — or not.
COMFORTABLE
Plenty of space. Everyone moves at their own pace.
Try a scenario 🟢 Calm room 🚪 One narrow exit 🔴 The crush ⬛ Pillar by the door 🚪🚪 Two exits
colour: pressure colour: speed density field flow field ⤳ fluid view 💧 liquid trails

Fundamental diagram

Each dot: local density vs speed. Packing collapses speed — the fluid signature.

Inflow vs. outflow

Blue = arrivals set. Amber = exits live. Shaded gap = people accumulating.

Venue builder

Room shape changes the wall layout. Doors and objects reset.
🚪 door ⬤ pillar ▬ wall ✕ erase 👊 shove
Click a wall segment on the canvas to add a door. Click an existing door to toggle it open/closed.
0.7 m
0
Click a door's open/closed toggle to control it live during simulation.

Crowd

3.5 p/s
Arrivals per second from the left intake. Zero = evacuation only.
1.3 m/s
moderate
How much personal space people surrender.
1.0×

Live readout

Inflow · set
3.5 p/s
Outflow · live
0.0 p/s
Net balance
0.0 p/s
Peak density
0.0 /m²
In room
0 ppl
Queue outside
0 ppl
Pressure
0.00 /s²
Escaped
0 ppl
PRESSURE— /m²
calmdenseturbulentcrush
How to use it. Pick a tool (door / pillar / wall / erase) then click on the canvas. Doors snap to wall segments; click to toggle open/closed live. Pillars and walls are solid obstacles — the crowd routes around them. Agents aim for the nearest open door and are admitted from the left. Open multiple exits to watch flow split.