sand3d
Write 3D models as short Python programs built for LLMs over Blender.
Write 3D objects as short programs over Blender's bpy for AI generation
sand3d is a Python library that lets you define 3D objects as compact code using Blender's bpy engine. It suits engineers and developers looking to prompt LLMs to generate precise 3D geometry and articulated assemblies without manual coordinate math.
What it is
The library provides a flat s3d API covering profiles, solids, edits, framing, and articulation that fits entirely within an LLM prompt. It outputs deterministic meshes and handles exports to formats including GLB, URDF, USDA, OBJ, and STL.
Who it's for
It suits AI engineers, mechanical designers, and developers building procedural 3D generation pipelines. It does not suit traditional CAD artists who rely strictly on direct GUI manipulation.
Key features
Low Token Footprint
Parts take significantly fewer tokens than equivalent Blender Python, CadQuery, or FeatureScript code.
Named References
Access parts, edges, and faces by name instead of hand-computed coordinate math.
Multi-Format Export
Export directly to GLB, URDF, USDA, OBJ, and STL formats with a single function call.
Built-in Articulation
Declare joints and assemblies directly within your programmatic workflow.
Up and running in 3 steps
Our honest verdict
What's great
- Entire API fits inside a prompt of about 3,600 tokens for LLM context windows
- Produces bit-for-bit deterministic meshes from identical program inputs
- Includes datasets covering Objaverse, CAD, Articraft, SimReady, and AutoMate
- Directly integrates with Blender's bpy engine for robust underlying geometry operations
Where it falls short
- Requires managing Python and Blender environment dependencies like specific bpy wheels
- Python 3.12 and Intel Mac environments have specific installation restrictions
- Requires writing procedural code rather than using visual 3D modeling tools
Pricing & license
Free under its open source licence, with the only cost being your own compute and setup time.
Open remote AI-training roles
767 open remote AI-training roles, updated November 14, 2026; most pay $20–$175 an hour. Zekai lists them free; the application goes to the employer’s platform.
Alternatives
Use it, or have us set it up
FAQ
What Python versions are supported?
Python 3.13 is recommended, with Python 3.11 supported for environments lacking bpy wheels like Intel Macs.
What file formats can sand3d export?
It supports GLB, URDF, USDA, OBJ, and STL, with additional formats like USD derived through USD tools.
How does sand3d handle object joints?
You can declare joints and motion ranges directly in your code, which export into URDF and GLB node extras.
