Hosting — three classes. Most of the engine runs headless: world, simulation, physics,
gameplay, navigation, the logic of animation/particles/terrain/UI, and input. What needs more:
(1) visible output (rendering, camera) needs a GPU/render host; (2) audio and Lua scripting
need their own resource — an audio device, a script VM — not a GPU; (3) a few subsystems
(templates/prefabs, input bindings, scripting) need their resource registered, which a bare
headless host doesn’t do unless the project’s game does. Each page says which applies; see
Troubleshooting.
“AI” here is never an in-engine LLM. The agents that drive Euca are external clients; in-engine
AI is classical and deterministic (behavior trees), and
asset generation calls external 3D-gen providers and never touches ground
truth.
Build a world
Entities & components
Spawn/despawn, patch components, tag, observe — the world as a table.
Rules as data
when X do Y as inspectable data, changeable mid-run.Templates & prefabs
Reusable runtime templates and static registered prefabs.
Scenes & levels
Load a whole world from one scenario; save/load scenes and levels.
Simulate & play
Simulation
The deterministic tick loop, play/pause/step, match lifecycle.
Gameplay & combat
Health, damage/heal, projectiles, triggers, teams, scoring.
Abilities & status effects
Cooldown/mana abilities, stat modifiers, DoTs, crowd control.
Units & roles
Compose units from gameplay components — health, team, combat, gold, roles.
Inventory & economy
Inventories, equipment, and the gold economy.
AI behaviors
NPC steering + a behavior-tree library. Classical, not an LLM.
Navigation
Grid navmesh, A* pathfinding, steering agents.
Input
Key/mouse/gamepad bindings, action maps, a context stack.
Render & present
Camera & rendering
Camera control + the PBR forward renderer. Needs a GPU host.
Materials & post-processing
PBR materials, the post stack with presets, volumetric fog.
Animation
State machines, blend spaces, montages, root motion, IK.
Particles
CPU emitters — gravity, aging, color-over-life, shapes.
Terrain & foliage
Heightmap terrain, brush editing, colliders, instanced foliage.
UI & HUD
Flex layout, widgets, hit-testing — HUD text and bars.
Audio
Spatial + global audio, buses, reverb, occlusion. Needs a device.
Asset generation
Text/image → 3D across 4 wired providers (Tripo, Meshy, Rodin, Hunyuan); appearance ≠ ground truth.
Experiment & verify
Forks & counterfactuals
Deep-clone the world, intervene, diff, drop.
The world-engine API
observe · peek · step · fork — and the
peek == step invariant.Assertions & manifest
Testable expectations, probe, a self-grading feature manifest.
Determinism & replay
Byte-for-byte reproducible runs; the
state_digest oracle.Datasets
Exact structured state + ground-truth segmentation/depth channels.
Evaluation
Grade any world model against exact ground truth, in nats.
Platform & tools
The euca-studio editor
The visual editor — open any project, edit the scene as data, press Play. The game-engine face.
The euca CLI
A command-line client mapping to the HTTP API, with discover/explain.
Networking
A snapshot/delta replication + prediction library (not yet wired).
Scripting (Lua)
Sandboxed per-entity Lua with an ECS bridge and hot reload.
MOBA systems
A full Dota-style kit on the genre-neutral primitives.
Hosting & deployment
Run a server, target it — unauthenticated by default, with opt-in Ed25519 auth.
The full API
~114 endpoints, grouped, with schemas and a playground (hand-maintained OpenAPI snapshot).