About The Project

The Unity C# Trainer is a fully interactive learning tool designed to teach beginners the core principles of C# programming inside Unity. Unlike static tutorials or pre-recorded lessons, this project allows players to write real C# code, compile it in-game using Roslyn, and immediately see the results inside a live Unity environment.

The trainer features a complete workflow: a built-in script editor, a real-time console, a dynamic compiler, and a series of fully guided lessons ranging from basic variables to fixing a complete player controller used in a playable demo world.

Main Features

● In-Game Code Editor: Styled after modern IDEs with syntax highlighting.

● Roslyn Integration: Real C# compilation at runtime, using safe in-memory assemblies.

● 12-Stage Lesson System: Progressively teaches everything from basic syntax to movement logic.

● Interactive Console: Displays logs, errors, and runtime feedback exactly like Unity’s console.

● Fully Playable Demo World: After completing the course, players have the chance to program a Player Controller and use it.

● Template Injection: Lessons automatically insert helper code or starting templates.

Development Challenges

Performance: Unity by default does not have rudimentary support for Runtime code injection, utilising the Roslyn Compiler allowed for this to be possible but insuring Runtime code injection didn't cause any performance hitches was a huge undertaking.

Replicating Unity Functionality: When the core logic was implemented for Runtime code modification, ensuring certain voids like 'Update' would function like it would if it wasn't a Runtime injection seemed like it would be a huge problem to ensure proper functionality. I later worked out that I could link the user's 'Update' to the Roslyn Controller's 'Update'. Fetching the "User Script's" implementation and invoking it in the Roslyn Controller's implementation allowed for seamless 'Update' functionality as there was only 1 'User Script' running at a time

Lesson Display: In order to properly convey lessons to the player, I had to create a system that injects pre-made code that I wrote into the code editor. That was simple by creating a manager and a 'Lesson' class that holds the 'Block Name', 'Sample Code' and a simple toggle for if there is another lesson called 'DisableNextButton'. Conveying these lessons was made easy by utilising the interactive storytelling asset 'Fungus'. Small modifications to the code were made due to how the lesson manager was designed.

Unity Console Functionality: Utilising Unity's built-in console for error detection was a key part in making this game possible. Even though the code is injected in Runtime, the 'CSharpCompilation' dll that is a requirement for Roslyn. With the limited time I had to produce this project, I had to resort to an asset called 'Quantum Console' by 'QFSW'.

Code Editor: Wanting to replicate an IDE like Visual Studio or Rider lead to being a complicated process with figuring out syntax highlighting and intellisense. With how complicated intellisense is, it wasn't feasible in my given time frame to replicate it within Unity. When developing the compiler for the game, I planned on creating the code editor myself of which I did make progress in but because of the limited time I had, I utilised yet another asset called 'InGame Code Editor' by 'Trivial Interactive'. This allowed me to develop the project more than previously planned as I originally intended only 6 short lessons.

What I Learned

● How to integrate the Roslyn compiler safely inside Unity to support real-time code execution.

● How to generate and manage in-memory assemblies without freezing the editor or leaking memory.

● How to design a user-friendly code editor with live error feedback, template injection and safe script execution.

● How to build a sandboxed learning environment that lets beginners experiment without breaking the project.

● How to structure clear, incremental lessons that teach both coding concepts and practical Unity workflows.