Real-Time Debug Visualization via Inter-Process Communication in Unity Editor

Abstract

Debugging iterative geometric algorithms in a game engine editor presents a fundamental challenge: when execution is suspended at a breakpoint, the editor becomes non-interactive, making visual inspection of intermediate computational states impossible. This paper presents a debug visualization system that decouples rendering from the main application process through Inter-Process Communication (IPC) via memory-mapped files. Drawing commands - lines, points, meshes, text, and geometric primitives - are serialized using a binary command pattern and transmitted to a secondary Unity Editor instance, which renders them independently while the primary process is suspended. The system exposes a renderer abstraction through the IDrawContext interface, enabling custom rendering backends with no changes to the core system. Zero runtime overhead in production builds is guaranteed by C# conditional compilation. The system was developed and validated in practice during the implementation of geometric collision detection algorithms - including GJK, EPA, SAT, MPR, and incremental convex hull - within a bachelor's thesis project.