Leonnel Hammel

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Junior |

Passionate about writing efficient, clean code while embracing new challenges. Curious and driven problem solver who enjoys tackling complex systems and building games that both play great and are built on well-organized, maintainable, and performant code

Want to work with me?

< Technical Skills /> // Languages • Engines • Tools

Languages

Engines - API - Frameworks

Direct3D 12
Sfml Streamline Icon: https://streamlinehq.comSFML

Development Tools

JetBrains Rider

< Soft Skills /> // Communication • Teamwork • Proactive

Communication

To be an effective communicator, I ensure that what I say is professional, inclusive, and well received by others. I strive to be an approachable and reliable team member and follow through on commitments.

Eager to Learn

Every project has many opportunities to learn something new. I am always curious to learn from the project itself or from the talented people around me, continuously growing my skillset.

Teamwork

I want to be a colleague others can rely on, always willing to give and receive feedback. I endorse peer programming, code reviews, and discussions to make everything just a bit better.

Feedback Driven

I see constructive feedback as valuable information for growth. I frequently seek feedback on my deliverables and collaboration quality, then act on it to continuously improve my work.

Proactive

Dealing with blocks or setbacks requires dedication and willingness to not give up. I strive to find solutions with clear impact and options, or raise awareness of problems with the team.

Ownership

I take responsibility for the outcomes of my work and my impact on the team. When I miss the mark, I own it, learn, and put improvements in place so we move forward stronger.

< Work Experience /> // Current • Past • Future?

Jun – Aug 2024SwisscomSoftware Engineer Intern
C++WPFOOPCI/CD.NETGit
Jun – Aug 2025Vrai StudioGameplay & Tools Programmer
UnityC#VRMobileXRDOTS
Apr – Jun 2026 ✦SOGECLAIRGameplay Programmer
UnrealC++3CChaosUE5Physics
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SOGECLAIR, Toulouse FR

Gameplay Programmer
April 2026 - June 2026

Unreal
C++
Git
Jira
3C
Optimization
Chaos

Private Demo Vehicle

  • Implemented realistic torque, friction, and surface interaction
  • Developed a spline-following system featuring automatic speed adaptation based on curvature
  • Utilized Control Rig and IK (Inverse Kinematics) for custom animation setups
  • Created bespoke bone configurations and 3D model setups from scratch
  • Implemented real-time tire deformation utilizing Chaos Flesh and physics proxies
  • Hardened performance using industry-standard profiling tools: RenderDoc, NVIDIA Nsight, and PIX

Vrai Studio, Albi FR

Gameplay & Tools Programmer
June 2025 - August 2025

Unity
C#
VR
Git
Mobile
Jira
3C

Bunny Kids (Mobile Game)

  • Built a planet creation tool so non-technical staff could design and add new worlds without coding
  • Designed and delivered a custom in-app purchase (IAP) system by extending Unity’s IAP Catalog and existing implementation
  • Refactored and optimized an in-editor painting tool, profiling performance across devices and applying Unity Jobs/Burst optimizations for mobile hardware
  • Created, debugged iOS builds (Xcode, App Store) and Android builds (Gradle, Play Store)
  • Refactored and optimized in-editor tools with Unity Jobs/Burst for better mobile performance

L'aventure du Compost (VR Game)

  • Implemented an interactive camera gameplay feature (photo capture + insect collection) using Unity’s RenderTexture with performance-conscious scaling and draw call optimizations
  • Added player rotation controls and integrated haptic feedback on VR joysticks by combining Unity’s new Input System with Auto Hands
  • Profiled and optimized gameplay code (physics calls, conditional checks, draw calls), significantly improving FPS stability on standalone VR headsets with limited RAM and GPU resources

RecyclageVR (VR Game)

  • Developed a new gameplay mechanic for waste sorting, enabling players to separate materials into two waste streams using VR joysticks and in-world interactions
  • Optimized cloud-based API calls for dynamic waste pickup requests, reducing latency and improving system responsiveness across networked gameplay sessions

Unannounced Adventure Prototype

  • Implemented character controls (3Cs) and interaction systems using Unity’s new Input System, with collision optimizations for interaction whiskers
  • Designed and implemented a decoupled architecture leveraging Zenject, Event Bus patterns, and ScriptableObject-based service locators, reducing code coupling and improving maintainability
  • Supported early prototyping with a focus on performance and maintainability

Swisscom, Lausanne CH

Software Engineer Intern
June 2024 - August 2024

C++
WPF
OOP
Perforce
CI/CD
UI/UX
  • Assisted with software development, debugging, and testing. Optimized the internal issue detection system and enhanced user
    experience by reducing memory usage from 20% to 7% via C++ memory layout optimization techniques
  • Facilitated feature integration and conducted comprehensive code reviews. Implemented design team requests while ensuringadherence to project standards
  • Documented technical processes and improvements, ensuring thorough code commenting for future maintenance and developing scalable documentation to support team collaboration
  • Collaborated with cross-functional teams, achieving a 20% reduction in feature delivery time

< Projects highlight /> // Shipped • Past • Current : Games/Demos

Erebus

Released
20
4 Months
2026
Unreal Engine 5
GASP
Optimization
Buyoancy
Erebus is a short narrative technical game demo set in a dark fantasy world.
This project started as our final-year project at Creajeux to improve our game development and teamwork skills in Unreal Engine. As it grew beyond its academic scope, the team expanded from 10 to 20 members, welcoming external game, sound, and level designers.
I mainly worked as a support programmer, focusing on low-level engine systems and general technical tasks after taking a professional opportunity midway through development
Find Out More (Coming Soon)

BitForge

Released
1
9 Months
2025-2026
Assembler
C++
Direct3D 12
Rendering
SIMD
Multithreading
Designed and developed a custom real-time rendering engine combining C++20 and MASM x86_64, with a hybrid low-levelarchitecture for fine-grained control over performance and memory
Implemented a modern DirectX 12 deferred rendering pipeline, including G-buffer, shadow mapping, SSAO, volumetric fog, andtemporal anti-aliasing
Custom HLSL pixel shaders to implement real-time Screen-Space Reflections (SSR) utilizing a robust depth-buffer raymarching /raycasting algorithm to evaluate ray-scene intersection
Optimized CPU and GPU performance using SIMD vectorization and GPU-driven rendering techniques, improving scalability tocomplex scenes
Find Out More

Internal demo

Released
3
2.5 Months
2026
Unreal Engine 5
Vehicle Modular
PCG
Assemblies
Chaos System
Procedural Animation
This project was part of my contract at SOGECLAIR. The goal was to develop a small vehicle demo for the Eurosatory exhibition to showcase the vehicle's capabilities
Collaborating with the lead designer and artist, I implemented features while adhering to defined design guidelines and technical requirements
Implemented custom C++ gameplay systems, vehicle mechanics, IK-driven animation, PCG-generated environments, level integration, and GPU performance optimizations using RenderDoc and NVIDIA Nsight
Find Out More (Coming Soon)
Explore More Projects

< Education /> // Current • Past

Creajeux, Nimes FR

B.Sc. in Computer Science, major in Game Programming
2022-2026

1st Year: Foundations, Core Concepts & Basic Algorithms

  • Core Math & Programming: Fundamental Mathematics and procedural programming using C.
  • Computer Science Fundamentals: Introduction to basic algorithms (sorting, searching), Big O notation, and fundamental data structures (arrays, linked lists, stacks, queues).
  • Graphics & Production: Working with 2D graphic libraries and learning the basics of game production methods.
  • Collaboration & Professional Growth: Participating in workshops, masterclasses, and an English-language curriculum, alongside a joint project with 1st-year graphic design students.

2nd Year: Advanced Programming, Vector Math & AI/Patterns

  • Math & Coding Evolution: Transitioning to vector analysis mathematics and procedural programming in C++.
  • Advanced Computer Science & AI: Graph algorithms (A* pathfinding, BFS/DFS), memory management (pointers, dynamic allocation), and complex data structures (binary search trees, hash tables).
  • Software Design: Core design patterns frequently used in game development (Singleton, Factory, State Machine).
  • Graphics & Production: Continued work with 2D graphic libraries and game production methodologies.
  • Collaboration & Communication: Advanced workshops, masterclasses, English and communication skills, and a joint project with 2nd-year graphic design students.

3rd Year: Object-Oriented Programming, Advanced 3D Math, Shaders & Unity

  • Advanced 3D Mathematics: Matrix numerical analysis, linear algebra, 3D transformations, and quaternions (for smooth 3D rotations, avoiding gimbal lock).
  • Shaders & Graphics Pipelines: Introduction to programmable graphics pipelines, writing vertex and fragment/pixel shaders, manipulating buffers, lighting models, and visual effect creation.
  • Object-Oriented Programming: Mastering OOP paradigms natively in C++ and C#.
  • Engine Integration (Unity): Working extensively with Unity for 3D game development, mapping C# scripting to game objects, physics engines, and components.
  • Engine-Level Computer Science: Advanced spatial data structures (graphs, trees) and architectural design patterns (Observer, Command, Component pattern) applied to game engines.
  • Game Development Core: Deep dive into Gameplay, Game Engine, and Tools programming.
  • Collaboration & Soft Skills: Workshops, masterclasses, English and communication development, and a joint project with 3rd-year graphic design students.

4th Year: Unreal Engine, AAA Optimization & Network Engineering

  • Unreal Engine Systems & Production Core:
    • Advanced Engine Architecture: Deep interface with engine reflection systems for metadata management, automated garbage collection cycles, and memory safety abstractions. Mastering the core gameplay framework hierarchy to manage state, player input, and world actors.
    • Blueprint Integration Architecture: Designing modular boundary layers between code and visual scripting, exposing data securely, implementing polymorphic function overrides, and managing complex event execution flows via dynamic dispatch systems.
    • Advanced Materials & Custom Shaders: Constructing optimized node-based systems within the engine material editor; integrating custom HLSL blocks for specialized math; developing master materials, parameter-driven instances, vertex displacement physics, and post-process effects.
    • Animation Engineering Pipelines: Implementing runtime state machines, blend spaces, procedural inverse kinematics, and raw bone transformation modifications within the engine's animation evaluation loops.
  • High-Level Systems Programming & Architecture: Advanced programming utilizing entity-component-system patterns to enforce strict data locality and maximize performance throughput, alongside offloading logic to background threads using engine-native task scheduling, managing synchronization through atomic operations, and handling complex dependency graphs.
  • Low-Level Code & Hardware Optimization:
    • Code Profiling: Identifying performance bottlenecks, stalls, and critical path computations across isolated engine threads using industry-standard telemetry, hardware-sampling, and statistical analysis tools.
    • Data Locality & CPU Cache: Designing hardware-aware, cache-friendly systems to minimize L1/L2/L3 cache misses. Shifting from pointer-heavy object architectures to contiguous, array-based memory layouts.
    • Micro-optimizations: Maximizing instruction pipelining, optimizing branch prediction, minimizing context switching, and implementing branchless programming techniques to achieve peak frame-time consistency.
  • Video Game Network Engineering (Low-Level to Cloud):
    • Socket Layer & Binary Serialization: Master low-level socket abstractions. Building custom binary stream packing to bypass text-based overhead, implementing manual endianness translation, data quantization, and delta compression.
    • Reliable Transport Layers: Engineering bespoke reliable transport protocols over raw datagram sockets to avoid head-of-line blocking; implementing sequence verification, rolling acknowledgments, and manual packet fragmentation management.
    • Synchronization Topologies: Coding robust replication architectures, including deterministic lockstep models, predictive input rollback systems for latency compensation, and authoritative client-server models with historical interpolation.
    • Cloud Infrastructure & Microservices: Architecting decoupled online services (Matchmaking, Inventory, Auth) using microservice patterns; routing transactions via API gateways and containerizing server instances for scalable cloud deployment.
  • Advanced CS, Math & Production:
    • Applied Engineering Math: Multivariable differential calculus and numerical approximation methods for curve fitting, animation interpolation, and physics trajectory estimation.
    • Spatial Partitioning: Developing advanced tree-based structures (2D/3D partitioning) to reduce query complexity for collision and visibility detection.
    • Capstone Production: Masterclasses and a final-year team-based capstone project.

Creajeux, Nimes FR

Preparatory Year for the Bachelor
2021-2022

Preparatory Year: Foundations & Game Development Basics

  • Math Refresh: Analysis, algebra, and geometry fundamentals for 2D/3D game development.
  • Programming (Lua, 2D Projects):
    • Fundamentals: Core data structures and basic algorithms.
    • Paradigms: Procedural, event-driven, and functional programming; modular design and error handling.
    • Game Loop: Main loop, sprites/animation, collisions, input, and audio.
  • Capstone Group Project: Specification writing, prototyping, agile workflow, and final presentation.
  • 3D Modeling (Maya): Fundamentals, interface, and basic production pipeline.
  • Digital Imaging (Photoshop): Core workflow, key tools, pixel art, and color theory.
  • Game Culture: Industry overview, studio roles, iconic franchises, and notable creators.
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Hi, I'm Leonnel

Junior Engine & Gameplay Programmer. I see myself as a curious problem solver who’s always eager to learn and improve. I love working on games that not only feel great to play but are also built on clean, well-organized, maintainable, and performant code.. I enjoy taking on complex challenges, sometimes a little too much, as I tend to get fully absorbed until I find the perfect solution

Curious to learn more? Check out my resume at the top for my contact details, or connect with me on social media. You can also message me directly here →
Designed & crafted by Leonnel Hammel · © All rights reserved