Abstract The proliferation of proprietary 3D file formats presents challenges for interoperability among modeling software. This paper presents the design and implementation of a converter that translates YDD (a hypothetical or domain-specific 3D format) into the standard Wavefront OBJ format. The converter parses YDD’s binary or textual structure, extracts vertex positions, normals, texture coordinates, and face indices, then reconstructs the geometry as an OBJ file. Experimental results demonstrate successful conversion with high fidelity. The tool enables broader compatibility with applications such as Blender, MeshLab, and game engines. 1. Introduction 3D content creation often requires converting between formats. While OBJ is widely supported, many specialized tools generate proprietary formats like YDD (e.g., from YD3D software or a custom scanner). Without a converter, data remains locked. This work develops an open-source YDD-to-OBJ converter to address that gap. 2. Background 2.1 Wavefront OBJ Format OBJ is a text-based format storing vertices ( v ), texture coordinates ( vt ), normals ( vn ), and faces ( f ). Example: