F3D vs Sketchfab

F3D is free software for viewing 3D data, browsing models, and generating renderings. It supports lighting and materials for realistic rendering, animations with GPU-accelerated skinning for character rigs, and visualization tasks such as CAD, Gaussian splatting, volume rendering, and scientific work. Its supported formats include VTK, STL, DICOM, STEP, OBJ, glTF, FBX, USD, IFC, and Gaussian splat files, among many others. Packages are available for Windows, macOS, Linux, and Android, and a browser viewer can open or accept dropped files and provides rendering and display controls. Developers can use a Python package, a beta JavaScript/WebAssembly package, or the libf3d C++ library with Python and Java bindings. F3D is distributed under the BSD 3-Clause License. Some capabilities have specific limits: FBX PBR materials and Alembic materials are unsupported, while Gaussian splatting requires OpenGL 4.3, which macOS does not support. Documentation also says volume rendering and HDRI need a decent GPU. Plugins can vary by package.

Sketchfab is a platform for publishing and finding 3D content through an interactive viewer. The viewer can be embedded on websites, allowing 3D and VR viewing without leaving the host site. Its built-in editor adjusts orientation, materials, lighting, camera parameters, and post-processing filters. Upload formats include OBJ, FBX, Blender, STL, and glTF, and exporter plugins are available for Blender, Maya, SketchUp, Unity, and ZBrush. APIs support model uploads, data access, downloads, and viewer control or embedding. The Download API provides glTF, GLB, and USDZ, not source formats such as FBX and OBJ; owners control whether their models are downloadable. Basic is free and allows model files up to 50MB. Pro costs $15 a month billed yearly, with a 200MB model limit and private uploads. Premium costs $79 a month billed yearly, with a 500MB limit and advanced embed customization. Enterprise pricing is by quote.