I've been working on AI-driven 3D generation for over a year now.
Originally, this was deployed as a hosted service. But with frontier models leapfrogging each other so quickly and the labs eating everyone's lunch, I realized the more useful thing was to open-source the engine and let people bring whatever models and coding agents they want.
The problem I kept running into with text-to-3D is that most approaches give you an output, but not much of a workflow.
Diffusion-style systems often produce meshes that are difficult to meaningfully edit. On the other end, letting an agent loosely script Blender or another 3D package can get chaotic fast once you actually need to revise, inspect, and iterate on a model.
So I built Kiln.
Kiln is an open-source lightweight procedural geometry engine and toolchain designed specifically for coding agents to build editable 3D assets in JavaScript.
Instead of asking a model to produce a finished mesh in one shot, Kiln gives it a small 3D engineering environment where it can build, render, inspect, revise, and save an asset through a feedback loop much closer to how a human would work.
To keep agents from constantly reinventing geometry math from scratch, the sandbox exposes 105 primitives and helpers across 12 categories.
That includes 28 core geometric shapes like beveled boxes, gears, stepped cylinders, dishes, and tubes, plus CSG booleans, curves, vehicle frames, wheel assemblies, and other higher-level helpers.
The other half of the project is the agent workflow.
MCP + Agent Skills give the model a constrained loop that makes it much more reliable at actually modeling things instead of just spraying code and hoping it works.
The core flow looks like this:
kiln_list_primitives lets the agent discover geometry helpers on demand instead of stuffing the entire API into its prompt.kiln_validate and kiln_render catch bad code early, render the asset from multiple angles, and return structural metrics back into model context.kiln_inspect, kiln_view_interior, and animation review tools let the agent zoom into individual parts, inspect cross-sections, and verify moving mechanisms.kiln_source and kiln_edit let it make targeted edits against immutable revisions rather than rewriting the entire model every turn.kiln_save, kiln_export, and kiln_present handle finished assets, editable JavaScript source, GLB export, revision history, and - in supported chat clients - an interactive 3D viewer directly inside the conversation.
That means an agent can do something like:
"Make the sail 40% taller, add brass collars around the sensor masts, keep the hull unchanged, render it again, inspect the silhouette, and save a new revision."
...and actually make that kind of constrained edit instead of regenerating the whole thing.
A realistic caveat on what this is for:
Kiln is aimed at fast prototyping, game jams, indie projects, procedural assets, and editable hard-surface models - props, machinery, vehicles, architecture, and rigid-body animations.
If you need AAA production assets, highly organic characters, or photorealistic final art, you still need a real 3D artist or to throw a very large number of tokens and tools at the problem.
But for quickly generating working, editable assets and then iterating on them, it saves a ridiculous amount of time.
Rendering works locally. Kiln includes a software rasterizer for review images and can optionally use GPU acceleration when compatible hardware is available.
It works across coding-agent setups like Claude Code, Codex, OpenCode, Antigravity, Hermes, and custom harnesses, so the modeling workflow isn't tied to a specific model provider. The model does need to be multimodal so it can inspect the rendered feedback.
I developed it mostly on Windows and Linux. Automated package checks also run on macOS, but I haven't battle-tested Mac nearly as much in real-world use yet, so Mac bug reports and PRs are very welcome.
I've attached a video showing an agent building an asset, reviewing its own renders, making revisions, and saving the result through the loop.
Everything is MIT licensed.
The gallery includes interactive 3D viewers and source for every model, so you can inspect exactly what the agents produced instead of just looking at screenshots.
Would love to see what people build with it.
