Matera Digital

OBJ Parser

Project Write-up

OBJ Parser · Wavefront OBJ to binary converter in Zig

A small Zig project that reads Wavefront OBJ files and optionally reads MTL material files, converting them to an optimized binary format with verification tools. Built to learn Zig's explicit memory management and binary-safe parsing. MIT licensed.
Problem

Learning Zig's memory model through real parsing

I wanted to learn Zig's explicit memory management and binary-safe parsing by building something real — not a toy example. Parsing Wavefront OBJ files and converting them to an optimized binary format was a good fit: it requires reading text formats, handling materials, managing memory explicitly, and writing binary output that can be verified.

Solution

What I built

A small Zig project that reads Wavefront OBJ files, optionally reads MTL material files, and converts them to an optimized binary format with verification tools. The parser handles face vertex parsing and demonstrates core concepts including OBJ file format handling, binary format design, memory management, and parsing techniques.

Parsing & conversion

  • Reads Wavefront OBJ files and parses vertices and faces
  • Optionally reads MTL material files
  • Converts to optimized binary format
  • Verification tools to validate binary output
  • Face vertex parsing implementation

Core concepts explored

  • OBJ file format structure and parsing
  • Binary format design for compact storage
  • Zig's explicit memory management
  • Binary-safe parsing techniques
  • Build system with build.zig
My Role

What I did

  • Solo developer — built the entire project to learn Zig
  • Implemented OBJ file parser reading vertices and faces
  • Added optional MTL material file reading
  • Designed and implemented binary output format
  • Built verification tools to validate converted output
  • Learned Zig's explicit memory management and binary-safe parsing
  • Created example files (cube.obj, cube.mtl) for testing
What's in the Repo

Real artifacts you can verify

  • GitHub repo: github.com/BradleyMatera/obj-parser
  • Live demo: No live demo — no GitHub Pages deployment (it's a CLI tool)
  • Commits: 2 commits
  • Code size: 21KB of Zig code
  • Created: January 18, 2025
  • License: MIT
  • Repo structure: src/main.zig (entry point), src/root.zig (parser logic), examples/cube.obj, examples/cube.mtl, build.zig
  • Honest limitations: This is a very small project — 2 commits, 21KB of Zig code, no GitHub Pages deployment. It's a learning exercise, not a production tool. Focuses on 2D models (not full 3D). It's small but it taught me Zig's memory model.
Tech Stack

Technologies used

ZigWavefront OBJMTLBinary formatbuild.zig