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.

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 scene transitions
• 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
• EventBus publish-subscribe for game events
• 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)

• Julia 1.9+ — julialang.org
• GLFW — sudo apt install libglfw3 libglfw3-dev (Ubuntu) / brew install glfw (macOS)
• Vulkan SDK (optional) — lunarg.com

using Pkg
Pkg.develop(path="/path/to/OpenReality")

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)

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

MIT License. See LICENSE for details.