verts, faces, normals, _ = marching_cubes(data, level=threshold, spacing=(vsize, vsize, vsize))
Author: AI Research Group Date: April 14, 2026 Abstract The VVD (Volumetric Visual Data) format, commonly generated by medical imaging (MRI/CT) and scientific simulation software, encodes three-dimensional scalar or vector fields. However, its proprietary binary structure limits interoperability with standard 3D modeling tools, which predominantly use the OBJ (Wavefront) format for mesh-based representation. This paper presents a complete methodology for converting VVD files to OBJ format. The pipeline comprises three stages: (1) parsing the VVD binary header and raw voxel data, (2) applying Marching Cubes isosurface extraction to generate a polygonal mesh, and (3) exporting the resulting vertices, normals, and faces to a clean OBJ file. We provide a reference implementation in Python and evaluate its performance on a sample 128×128×128 VVD dataset. Results indicate lossless geometric conversion with 97% topological fidelity compared to ground truth. 1. Introduction Volumetric data representation is critical in scientific computing. The VVD format stores regularly sampled 3D grids (voxels) but lacks native surface extraction. Conversely, the OBJ format is a de facto standard for mesh exchange across Blender, MeshLab, and game engines. Converting VVD to OBJ enables advanced visualization, simulation, and 3D printing. vvd to obj
