3D

A 3D Game Engine leveraging a software-based 3D rendering for Perspective Projection, Z-Buffering & Mesh Rendering

Features

• 3D Math Library: Vector and matrix operations for 3D transformations
• Software Rasterisation: Triangle rasterisation with barycentric coordinates
• Z-Buffer: Depth testing for proper 3D rendering
• Perspective Projection: 3D to 2D projection with field of view
• Back-face Culling: Optimisation to skip invisible triangles
• Camera System: First-person style camera with position and rotation
• Mesh Rendering: Support for triangular meshes with colored faces

Controls

• WASD: Move camera forward/backward and strafe left/right
• Arrow Keys: Rotate camera left/right
• Q/E: Move camera up/down

Project Structure

3D/
├── cmd/
│   ├── game.go          # Game Loop & Input Handling
│   └── main.go          # Entry Point
├── pkg/
│   ├── renderer.go      # 3D Renderer Implementation
│   ├── math.go          # 3D Math Utilities (Vec3, Mat4)
│   └── mesh.go          # Mesh & Triangle Definitions
├── go.mod
└── README.md

Getting Started

Prerequisites

• Go 1.21 or higher
• Git

Installation

1. Clone the repository:

git clone https://github.com/WillKirkmanM/3D
cd 3D

2. Install Dependencies:

go mod tidy

3. Run the engine:

go run cmd/main.go

Usage Example

// Create a new game instance
game := NewGame()

// Create a renderer
renderer := pkg.NewRenderer(800, 600)

// Create a cube mesh
cube := pkg.NewCubeMesh()

// Render the mesh with a rotation transform
transform := pkg.RotationY(time.Now().Sub(startTime).Seconds())
renderer.RenderMesh(cube, transform)

Technical Details

Rendering Pipeline

1. Model Transform: Apply object transformations (rotation, translation, scale)
2. View Transform: Apply camera position and rotation
3. Projection: Convert 3D coordinates to 2D screen coordinates
4. Clipping: Remove triangles outside the view frustum
5. Back-face Culling: Skip triangles facing away from camera
6. Rasterisation: Fill triangles pixel by pixel using barycentric coordinates
7. Z-Testing: Use depth buffer to handle overlapping surfaces

Extending the Engine

Adding New Mesh Types

func NewPyramidMesh() *pkg.Mesh {
    return &pkg.Mesh{
        Triangles: []pkg.Triangle{
            // Define triangle vertices and colors
        },
    }
}

Adding Lighting

The engine can be extended with basic lighting by calculating dot products between triangle normals and light direction vectors.

Adding Textures

Texture mapping can be implemented by interpolating UV coordinates across triangles during rasterisation.

Dependencies

• Ebiten v2 - 2D game library for Go
• Go standard library (math, image, etc.)