Koi Pond Simulator (2D) | mysimulator.uk

Koi Pond

Fish speed 1.0x

Number of fish 14

Ripple strength 1.0

Time of day Day

Display

Show lily pads Schooling behavior

Koi drifting freely around the pond.

Live Readout

Fish in pond

Active ripples

How it works

This top-down 2D view reimplements the same koi pond mechanic as its 3D companion using plain canvas drawing: each koi steers with a heading and turning phase rather than teleporting, banking its tail as it swings direction, and drifting slightly deeper or shallower to avoid overlapping neatly.

Switch on schooling behavior to add simple flocking rules — each fish nudges its heading toward the average direction and position of its nearest neighbors while keeping a minimum distance, the same alignment/cohesion/separation balance that produces real schools of fish.

Moving the mouse over the water spawns expanding ripple rings and gently pulls nearby fish toward the disturbance, mirroring the pointer-driven wave shader in the 3D version. The time-of-day slider recolors the water and light from a cool blue morning through bright midday green to a warm dusk amber, exactly like the directional-light retint in the 3D scene.

Move mouse over water to attract fish & ripple the surface