Building a 3D kart racer that runs in a browser
2026-11-02 · Sagar Studio
Nitro Lanes is our first 3D game: a kart racer with drifting, boosts, a mini map, split screen for two players and online races with friends. It runs in the browser on phones as well as computers. Here is what mattered most.
Separate the race from the pictures
The race itself, the karts, the track, the collisions and the computer drivers, runs as plain logic that knows nothing about graphics. The 3D view only draws what the race says. That made it possible to test whole races automatically without a screen, and to use the same race logic for online play.
Fast enough for phones
Phones are the hard part. We keep the number of separate objects small, reuse materials and keep distant scenery simple. The aim is a steady frame rate rather than the most detail.
Two players on one screen
Split screen draws the scene twice, once for each kart, which doubles the work. Each half gets its own camera and mini map.
Racing friends online
For online races one player opens a private table and shares the code or link, and friends join from their own devices. While racing, the karts' positions are sent between the players continuously.