Co-op space-survival voxel sandbox
Project Persei
Project Persei is a co-op space-survival voxel sandbox built on real exoplanet data. You build a ship block by block, leave a frozen Earth and cross the actual galaxy: all 6,278 confirmed NASA exoplanets, rendered at their true galactic coordinates.
The challenge
An engine-level project on an open-source engine, with zero purchased assets: the world, the ships, the textures and the sound all have to be generated, and it all has to stay smooth on the JVM.
Key decisions
- 01
A streaming voxel world
32³ chunks with cross-chunk face culling, procedural terrain and biomes, fluids, power circuits, crafting, farming and weather.
- 02
Ships you build, then fly
Ships are built block by block, then carved into flyable meshes, with seamless transitions from a planet's surface to space.
- 03
The real galaxy
All 6,278 confirmed NASA exoplanets at true galactic coordinates, with physics-based rules deciding how each one looks. Textures are painted at runtime, the audio is fully procedural, and the water uses custom GLSL shaders.
- 04
Profiler-driven performance
Removed per-frame allocation hot paths (the worst one was 750k objects per second), tuned generational ZGC from JFR profiles, batched chunk remeshing and built a delta-based atomic save system.
Results
- ~35k
- lines, engine-level, solo
- 6,278
- real exoplanets at true coordinates
- 0
- purchased assets
- 750k/s
- allocation hot path removed
