No install, no store
The game runs in a browser tab on WebGPU. A link is the whole distribution channel.
Use cases
One engine, three kinds of world.
Scale, determinism and zero-install delivery make Bract a strong engine for games. They are exactly what simulation and digital twin teams need too.
01 · Games
Open worlds that ship as a link.
Players click and they are in. Bract was built for worlds too large to author by hand, with streaming, LOD and shadows designed to hold up from the horizon to the ground under the player.
Worlds from a seed
Terrain, biomes, foliage and water are generated deterministically, so a large world ships in kilobytes.
Planetary scale
Double-precision positions and a floating origin let players travel from orbit to the ground without precision artifacts.
Replayable physics
Fixed-step, tiered-deterministic simulation makes replays, rollback and networked play practical.
Data-driven feel
Playbook rules, compute particles and spatial audio react to gameplay events without bespoke code.
Editor in the browser
Build, tune and play-test worlds in the same environment the player will use.
02 · Simulation
Simulations you can reproduce, run headless, and share.
Training, research and autonomy work need runs that can be repeated exactly. Bract treats determinism and headless execution as engine features, not afterthoughts.
Determinism tiers
Bit-exact CPU math, structurally stable GPU generation and visually stable rendering, each guarded by CI canaries.
Headless execution
A null render adapter runs the full engine without a GPU, so scenarios can run at scale in CI or the cloud.
Swappable physics
Jolt, Havok and a native solver sit behind one adapter contract. Compare solvers without rewriting scenarios.
Physically based environment
Spectral atmosphere, sun position from ephemeris data, weather and FFT oceans give sensors a credible world.
Scenario variety
Seeded procedural generation produces endless, reproducible terrain variations for coverage testing.
Shareable results
Send a link instead of a build. Reviewers open the same scenario in their browser.
03 · Digital twins
Large-area twins that open in any browser.
Digital twins are only useful when people can reach them. Bract streams large environments into a browser tab, so operators, clients and field teams can share one live view without installing anything.
Zero-install access
Stakeholders open a link on the hardware they already have. No plugin, no desktop client, no IT ticket.
Streams what is visible
A residency system pages geometry, textures and shadows by camera need under a fixed GPU budget.
Virtual textures and geometry
Surface detail and refinement geometry stream on demand, keeping close-up detail without loading the whole site.
Precision at any extent
Double-precision world space keeps sites, regions and whole planets in one coordinate system.
Live conditions
Time of day, sun position and weather are simulated, so the twin shows light and conditions as they are.
Typed integration
Every subsystem sits behind a typed contract, so data feeds and custom tools attach without forking the engine.
Early access 2026
Tell us what you are building.
Early access opens in waves for studios, technical artists and teams building large worlds on the web. Tell us what you are making.