OpenReality

A declarative, code-first game engine written in Julia.

OpenReality provides AAA-quality rendering with a clean functional API. Define scenes as composable entity trees, attach PBR materials and physics, and render with a single function call — on OpenGL, Vulkan, WebGPU or Metal.

Features

Rendering

• Physically-Based Rendering (Cook-Torrance BRDF, metallic/roughness workflow)
• Deferred + forward hybrid pipeline
• Cascaded Shadow Maps (4 cascades)
• Image-Based Lighting (procedural sky, HDR environment maps)
• Screen-Space Reflections (SSR)
• Screen-Space Ambient Occlusion (SSAO)
• Temporal Anti-Aliasing (TAA)
• Post-processing: bloom, tone mapping (Reinhard, ACES, Uncharted2), FXAA
• Advanced materials: clear coat, subsurface scattering, parallax occlusion mapping, emissive
• CPU-simulated particle system with billboard rendering
• Immediate-mode UI/HUD (text, buttons, progress bars, images)
• LOD system with dithered crossfade transitions
• Heightmap terrain with chunk-based LOD and splatmap layers

Engine

• Entity Component System with O(1) component operations
• Immutable, functional scene graph
• Four rendering backends: OpenGL, Metal (macOS), Vulkan (Linux/Windows), WebGPU (experimental)
• Full-featured impulse-based physics engine (PGS solver with warm-starting)
• 6 collider shapes: AABB, Sphere, Capsule, OBB, ConvexHull, Compound
• Joint constraints: ball-socket, distance, hinge, fixed, slider
• Spatial hash broadphase, GJK+EPA narrowphase, raycasting, CCD
• Trigger volumes, island-based sleeping, friction and restitution
• Keyframe animation with step, linear, and cubic spline interpolation
• Skeletal animation with vertex skinning (glTF 2.0 skin loading)
• 3D positional audio (OpenAL) with spatial attenuation and Doppler effect
• glTF 2.0 and OBJ model loading
• Built-in FPS player controller
• Scene export to binary ORSB format for web deployment
• Game State Machine (FSM) with guarded transitions and history
• GameContext for deferred entity spawning/despawning
• ScriptComponent lifecycle (on_start, on_update, on_destroy)
• Collision callbacks (enter, stay, exit)
• Prefab system for reusable entity templates
• Enhanced EventBus: priority listeners, one-shot, deferred events, cancellation
• Game Config with TOML loading, difficulty presets, hot-reload
• Timers: one-shot, interval, entity-scoped auto-cancel
• Cooperative coroutines with yield_wait, yield_frames, yield_until
• Tweens & easing: 18 easing curves, chaining, ping-pong, loop modes
• Behavior trees: selector, sequence, parallel, decorator nodes with blackboard
• Health & damage: armor, typed resistances, knockback, auto-despawn
• Inventory & items: slot-based inventory, item registry, world pickups
• Quest & objectives: kill/collect/reach/interact/custom objectives, auto-tracking
• Dialogue system: branching trees, per-choice conditions, quest integration
• Debug console: in-game terminal, custom commands, on-screen watches
• Camera controllers: third-person, orbit, cinematic
• Input mapping with gamepad support
• Animation blend trees (1D and 2D blending)
• Depth of field, motion blur, vignette, color grading
• Opt-in multithreading with snapshot-based parallelism
• Instanced rendering for batched draw calls
• AssetManager with async loading
• Save/load game serialization
• Debug drawing (lines, boxes, spheres)

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Core Contributers:

Really apperciate your contribution!!!!

ameligrana - first ever contributer to OpenReality 🎉

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Quick Start

Install

One-liner (recommended):

# Linux / macOS
curl -fsSL https://open-reality.com/install.sh | sh

# Windows PowerShell
irm https://open-reality.com/install.ps1 | iex

Or build from source:

Prerequisites: Julia 1.9+ (julialang.org), GLFW (sudo apt install libglfw3 libglfw3-dev on Ubuntu / brew install glfw on macOS), optionally Vulkan SDK (lunarg.com).

git clone https://github.com/sinisterMage/Open-Reality.git
cd OpenReality
julia --project=. -e 'using Pkg; Pkg.instantiate()'

Hello World

using OpenReality

reset_entity_counter!()
reset_component_stores!()

s = scene([
    create_player(position=Vec3d(0, 1.7, 5)),

    entity([
        DirectionalLightComponent(direction=Vec3f(0.3, -1.0, -0.5), intensity=2.0f0)
    ]),

    entity([
        cube_mesh(),
        MaterialComponent(color=RGB{Float32}(0.9, 0.1, 0.1), metallic=0.9f0, roughness=0.1f0),
        transform(position=Vec3d(0, 0.5, 0)),
        ColliderComponent(shape=AABBShape(Vec3f(0.5, 0.5, 0.5))),
        RigidBodyComponent(body_type=BODY_STATIC)
    ]),

    entity([
        plane_mesh(width=20.0f0, depth=20.0f0),
        MaterialComponent(color=RGB{Float32}(0.5, 0.5, 0.5), roughness=0.9f0),
        transform()
    ])
])

render(s)

Controls

Key	Action
W / A / S / D	Move
Mouse	Look around
Shift	Sprint
Space	Up
Ctrl	Down
Escape	Release cursor

Documentation

Guide	Description
Getting Started	Installation, tutorials, and your first scene
API Reference	Complete reference for all components, functions, and types
Architecture	Engine internals and design decisions
Examples	Annotated code samples for common patterns

Running Tests

using Pkg
Pkg.activate(".")
Pkg.test()

License

MIT License. See LICENSE for details.