Gears

A 3D game engine written in Rust with an Entity Component System architecture, physics simulation, and pathfinding.

Requirements

• MSRV is Rust 1.89
• GPU with support for Vulkan, DirectX 12, Metal, or OpenGL ES

Examples

Run examples with:

cargo run --release --example <example_name>

Available examples:

• minimal - Basic scene with a rotating sphere
• custom_window - UI controls for manipulating objects
• physics - Physics simulation with falling objects
• animations - Basic GLTF animation system and complex mesh loading
• pathfinding - A* pathfinding with obstacle navigation
• sandbox - Lights, physics, and player controls
• interactive - HFSM controlled entities with pathfinding and user interaction

Architecture

The engine is organized into several crates:

• gears-app - Main application layer, game loop and systems
• gears-core - Core functionality and utilities
• gears-ecs - Entity Component System implementation with components
• gears-gui - GUI integration with egui
• gears-macro - Procedural macros for convenience
• gears-renderer - Rendering backend and animantions

Features

Rendering

• 3D model loading (OBJ, GLTF formats)
• Multiple light types: colored ambient, directional, and point lights
• Animation queues with configurable transitions
• Debug wireframe visualization for colliders

Physics

• Rigid body dynamics with mass and velocity
• AABB (Axis-Aligned Bounding Box) collision detection
• Static and dynamic body support
• Gravity simulation
• Collision response and resolution

Entity Component System

• Flexible component-based architecture
• Entity queries with read/write locks
• Async system execution
• Component markers for filtering and categorization
• Macros for simplified entity creation

Camera System

• First-person camera with mouse look
• Fixed camera positions
• Look-at controller for targeting specific points
• Configurable movement controllers with WASD controls
• Adjustable movement speed and sensitivity

HFSM and Pathfinding

• A* pathfinding algorithm with multiple heuristic options
• Dynamic obstacle avoidance
• Finite State Machine (FSM) for NPC behaviors
• Configurable states and substates
• Grid-based navigation with customizable cell sizes
• Target tracking and pursuit mechanics

User Interface

• egui integration for custom windows and overlays
• Interactive sliders and controls
• Real-time component manipulation

Input Handling

• Mouse and keyboard input
• Camera rotation and look controls
• Player movement (WASD + Space/Shift for vertical movement)
• Cursor locking and release (Alt key)
• Shooting mechanics with raycasting