Attalo Engine

A real-time 3D rendering engine written in Go, built on OpenGL 4.1 Core + GLFW.

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Features

Rendering

• PBR shading — Cook-Torrance BRDF with roughness, metallic, and ambient occlusion
• Image-Based Lighting (IBL) — full pipeline: equirectangular HDR → cubemap → irradiance map → GGX specular pre-filter → BRDF LUT
• HDR skybox — tone-mapped equirectangular sky with a procedural gradient + star field fallback
• Shadow mapping — PCF soft shadows via a 4096×4096 depth map with slope-scale bias
• Water — reflection/refraction FBOs, configurable color, wind direction, and clarity
• Particle system — GPU-driven emitters (rain, snow, custom effects)
• MSAA — 4× multisample anti-aliasing

World & Terrain

• Chunked streaming terrain — Perlin-noise height, dynamically generated per-chunk meshes as the camera moves
• Splatmap blending — 5 material types (Grass, Dirt, Road, Sand, Snow) painted per vertex
• Live terrain editing — real-time sculpting (raise/lower) and texture painting via the debug UI
• Path tool — click-to-place waypoints that stamp road geometry onto the terrain
• Collision world — AABB boxes, ramps (X and Z axis), and a configurable floor plane

Vehicles & Characters

• Car — Ackermann steering model with throttle, brake, and grip
• Boat — buoyancy and water locomotion
• Airplane — pitch/roll/throttle flight model
• Helicopter — lateral strafe, yaw, and altitude control
• Motorcycle / Bicycle — two-wheel variants
• Human — walk, run, jump, dance, and swim (surface + dive)
• Vehicle entry/exit — animated door approach and seat-snap sequence
• Skeletal animation with GLTF skin data; per-vehicle animation config

Asset Loading

• GLTF 2.0 — multi-mesh models, per-mesh PBR materials, embedded textures, alpha modes (opaque / mask / blend), skeletal animations
• OBJ — legacy .obj model support

Audio

• OpenAL via cgo — spatial 3D audio, static clips and streaming music
• OGG Vorbis and WAV decoding

Debug UI

• In-window ImGui inspector — entity/camera state, terrain editing tools, weather presets, hitbox visualisation

Weather System

8 built-in presets with smooth interpolation: Clear, Overcast, Foggy, Drizzle, Rain, Storm, Snow, Sandstorm

Each preset controls cloud cover, fog density/color, rain/snow intensity, and wind strength.

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Requirements

• Go 1.21+
• A GPU and driver supporting OpenGL 4.1 Core Profile
• GLFW system libraries (provided automatically via the Go module on most platforms)
• OpenAL runtime library

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Getting Started

git clone <repo-url>
cd AttaloNew
go run .

Place assets under assets/ (see Assets below). The engine falls back gracefully if the HDR sky or scene files are missing.

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Controls

Camera / Movement

Key	Action
W A S D	Move camera (free-fly) or drive active vehicle
Mouse	Look around
Space	Move camera up / jump (human) / climb (helicopter)
Left Ctrl	Move camera down / descend (helicopter)
Q / E	Pitch elevator (airplane) / yaw (helicopter)
Scroll wheel	Zoom (adjust FOV)
P	Toggle first-person / third-person camera

Interaction

Key	Action
E	Enter nearest vehicle / exit current vehicle (human)
G	Grab / move selected object
Space	Jump (human on ground)
C	Toggle dive mode (human in water)
G	Dance (human)

Terrain Editing

Key	Action
M	Toggle paint mode (click terrain to paint material)
N	Toggle sculpt mode (left-click raise, right-click lower)

Misc

Key	Action
`	Toggle debug UI
Esc	Release mouse cursor / clear selection / quit

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Project Structure

AttaloNew/
├── main.go                  # Scene setup and engine entry point
├── config/
│   └── scene.json           # Scene configuration
├── engine/
│   ├── engine.go            # Core loop, draw pipeline, input handling
│   ├── scene.go             # Scene graph: objects, entities, vehicles, lights
│   ├── scene_config.go      # Scene config loading
│   ├── weather.go           # Weather presets and smooth interpolation
│   ├── debug.go             # ImGui scene inspector
│   ├── imgui_platform.go    # GLFW input routing for ImGui
│   ├── imgui_renderer.go    # OpenGL ImGui draw-data renderer
│   ├── loading.go           # Asset loading helpers
│   ├── render/
│   │   ├── glsl_pbr.go      # PBR vertex + fragment shaders
│   │   ├── glsl_shadow.go   # Shadow depth shaders
│   │   ├── glsl_terrain.go  # Terrain splatmap shaders
│   │   ├── glsl_water.go    # Water shaders
│   │   ├── glsl_particle.go # Particle shaders
│   │   ├── shader.go        # Shader compilation + uniform cache
│   │   ├── texture.go       # Texture loading (PNG, JPEG)
│   │   ├── hdr.go           # HDR equirectangular texture loading
│   │   ├── ibl.go           # IBL map generation pipeline
│   │   ├── skybox.go        # Skybox rendering
│   │   ├── water.go         # Water FBO + reflection/refraction pass
│   │   ├── water_volume.go  # Underwater volume rendering
│   │   ├── particle_renderer.go
│   │   ├── terrain_shader.go
│   │   └── wireframe.go     # Hitbox wireframe overlay
│   ├── world/
│   │   ├── entity.go        # Base renderable: transform + meshes + AABB
│   │   ├── object.go        # Static scene object
│   │   ├── vehicle.go       # Shared vehicle physics base
│   │   ├── car.go
│   │   ├── boat.go
│   │   ├── airplane.go
│   │   ├── helicopter.go
│   │   ├── motorcycle.go
│   │   ├── bicycle.go
│   │   ├── human.go         # Character: walk/run/jump/swim/dance
│   │   ├── camera.go        # First-person and third-person cameras
│   │   ├── light.go         # Light types and Material definition
│   │   ├── mesh.go          # GPU mesh (VAO/VBO/EBO)
│   │   ├── skinned_mesh.go  # Skeletal mesh with bone transforms
│   │   ├── animated_model.go
│   │   ├── animation.go     # GLTF animation samplers and channels
│   │   ├── particle.go      # Particle emitter
│   │   ├── collision.go     # Hitbox, ramp, collision world
│   │   └── culling.go       # AABB + frustum culling
│   ├── terrain/
│   │   ├── terrain.go       # Chunked terrain manager
│   │   ├── splatmap.go      # Splatmap: per-vertex material weights
│   │   ├── materials.go     # Material definitions
│   │   ├── noise.go         # Perlin noise height generation
│   │   └── path.go          # Path/road tool
│   ├── loader/
│   │   ├── gltf.go          # GLTF 2.0 static model loader
│   │   ├── gltf_animated.go # GLTF 2.0 skeletal model loader
│   │   └── obj.go           # OBJ loader
│   └── audio/
│       ├── audio.go         # OpenAL device/context management
│       ├── source.go        # Static audio source
│       ├── stream.go        # Streaming audio source
│       ├── loader.go        # OGG Vorbis / WAV decoding
│       └── al.go            # OpenAL cgo bindings
└── assets/                  # Models, textures, HDR skies (not tracked in git)

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Assets

The assets/ directory is excluded from version control. At runtime the engine looks for:

Path	Description
assets/Skyboxes/*.hdr	Equirectangular HDR environment map
GLTF models, OBJ files, textures	Referenced from main.go or config/scene.json

Missing assets degrade gracefully — the engine falls back to a gradient skybox and built-in geometry.

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Dependencies

Module	Purpose
github.com/go-gl/gl	OpenGL 4.1 Core bindings
github.com/go-gl/glfw/v3.3/glfw	Window creation and input
github.com/go-gl/mathgl	Vector/matrix math (mgl32)
github.com/qmuntal/gltf	GLTF 2.0 parsing
github.com/inkyblackness/imgui-go/v4	ImGui bindings
github.com/jfreymuth/oggvorbis	OGG Vorbis decoding
golang.org/x/image	HDR / image decoding support

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License

See assets/license.txt for third-party asset attributions.