⚙️ Core Engine Features & Capabilities

• Isometric Orthographic Projection: A mathematically perfect parallel viewing frustum that maintains scale regardless of depth, overriding standard perspective lenses.
• 3D Unprojection Raycasting: Translates 2D screen-space mouse coordinates into 3D world-space vectors by computing the inverse of the View and Projection matrices.
• Software Rasterization (DDA): Bypasses hardware-accelerated line drawing to manually calculate and rasterize sub-pixel coordinates for UI elements (e.g., tactical crosshairs) using the Digital Differential Analyzer algorithm.
• Continuous Collision Detection: An optimized, CPU-bound Axis-Aligned Bounding Box (AABB) physics system processing hundreds of simultaneous overlaps at 60 FPS.
• Delta-Time Normalization: Fully decouples game logic, physics speed, and AI state machines from hardware processor speeds, ensuring mathematically consistent behavior across all hardware.
• Data Serialization: Persistent, offline state management and high-score routing via local JSON serialization. No external telemetry ensures total data privacy.

📐 Mathematical & Algorithmic Foundations

The engine relies on raw mathematical implementations rather than pre-built physics engines:

1. Matrix Transformations (TRS)

Entity spatial positioning is governed by the Model matrix ($M$), calculated by multiplying Translation ($T$), Rotation ($R$), and Scale ($S$) matrices:

2. Raycast Intersection (Screen to World)

To pinpoint aiming, the engine calculates the scalar distance 't' along a 3D ray vector to intersect the horizontal plane at the player's weapon height ($y_{target} = 1.0$):

3. AI Vector Normalization

Enemies calculate the Euclidean distance (d) to the player to generate a normalized directional vector, ensuring consistent travel speed regardless of angle:

📊 Comparative Engine Analysis

Why build a custom pipeline instead of using Unity or Godot? This table outlines the architectural tradeoffs and specific advantages of our native implementation.

📈 Performance Benchmarks & Engine Specs

The engine is highly optimized for its target scope, utilizing a heavily structured data layout.

🏗️ Project Architecture & Directory Layout

The codebase enforces strict separation of concerns, isolating mathematical logic, rendering commands, and state routing.

/3d-rpg-engine
│
├── /engine                  # Core Engine Modules
│   ├── renderer.py          # GPU execution, Uniform mapping, Texture loading
│   ├── camera.py            # Orthographic projections, Inverse View matrices
│   ├── mesh.py              # Trimesh parsing, VAO/VBO memory generation
│   └── ui_renderer.py       # Pygame 2D compositing, FSM routing, DDA algorithms
│
├── /entities                # Game Logic & Physics
│   ├── player.py            # Raycasting, Input polling, Transformation matrices
│   ├── enemy.py             # Vector normalization, Delta-time tracking, AI logic
│   └── projectile.py        # Object pooling, Trajectory math, Lifetime management
│
├── /shaders                 # Hardware-level GPU Code
│   ├── default_vertex.glsl  # MVP coordinate space transformations
│   ├── default_frag.glsl    # UV mapping, Base lighting, Alpha transparency
│   └── ui_vertex.glsl       # 2D Orthographic overlay rendering
│
├── /assets                  # .glb models, .png textures, fonts
├── main.py                  # Pygame execution loop, Context initialization
└── README.md                # Documentation

👥 Engineering Team

This engine was architected and developed collaboratively, with strict separation of concerns to ensure modularity and high-performance execution.

• Mojammel Hosain Jesan
  • Core Engine Architect & Graphics Developer
  • Engineered Camera MVP matrices, .glb asset memory translation, VAO/VBO architecture, and GLSL Shader compilation.
• Rakib Chowdhury
  • Physics & Spatial Logic Engineer
  • Designed Object-Oriented entity frameworks, AABB collision hit registration, vector normalization, and 3D unprojection logic.
• Abrar Mahir Chowdhury
  • Systems & State Flow Architect
  • Implemented Finite State Machine routing, UI compositing, persistent data serialization, and manual DDA algorithmic rendering.

Contact the Team: mojammelkhan567@gmail.com

⚖️ License & Copyright

Copyright (c) 2026 Mojammel Hosain Jesan, Rakib Chowdhury & Abrar Mahir Chowdhury.

ALL RIGHTS RESERVED.

This software, source code, and associated documentation files (the "Software") are the proprietary property of the copyright holders: Mojammel Hosain Jesan, Rakib Chowdhury, and Abrar Mahir Chowdhury.

1. RESTRICTIONS ON USE: You are strictly prohibited from using, copying, modifying, merging, publishing, distributing, sublicensing, and/or selling copies of the Software in any capacity.
2. NO COMMERCIAL OR PRODUCTION USAGE: This Software may not be used for any commercial, production, corporate, or revenue-generating purposes under any circumstances without the explicit, written permission of the copyright holders.
3. REPOSITORY ACCESS: The presence of this code in a public repository is strictly for portfolio viewing and educational reference. It does not grant any implicit or explicit rights to utilize the codebase.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.