3D object builds a model or a scene — real geometry you can orbit, inspect and edit in the scene editor. It's the template for three-dimensional work: a product object, a scene for a site, a parametric form.
What a 3D run builds
Brief it like a modeling brief — "a ceramic vase, lathe-turned, matte" — and the agent builds the geometry and the scene. The result opens in the orbit viewport: drag to orbit, zoom in, view from every angle. Under the viewport sits the scene editor — the outliner, the transform controls, the material and parameter panels the object exposes.
3D object · Devin · subagent · gate PASS · 2 sizes
Lathed Vase — A stoneware vase with a real rim and an inner wall you can see into — cream glaze, product-shot camera.
▸ the prompt that made it▾ the prompt that made it
“Model a 3D object: a stoneware vase, about 24 cm tall, with a narrow neck and a visible interior when viewed from slightly above. Cream glaze. Product-shot camera. Show me a side view and a view into the opening.”
Procedural and native
The object builds two ways, depending on what's available:
- Procedural — geometry described in
scene.design.json: parameters (height, radius, rings, hue, spin) the scene editor exposes as sliders - Native — a Blender-backed build for heavier authoring, when Blender is installed on the machine (see Blender)
The authoring backend shows on the scene status bar — "procedural + native" or "procedural" alone. Procedural work is always available; native adds the Blender recipes for heavier modeling.
The scene editor
Scene editor opens the editor over the preview: the outliner lists the
parts, the viewport shows the object, and the panels expose the parameters —
height, radius, rings, hue, spin — plus the material slots the object uses.
Edits preview live; committing writes scene.design.json as one undoable
step.
This is where 3D work actually happens: create a scene, add primitives (box, sphere, and the rest), move and shape them, assign materials — the editor is the tool, the agent's result is the starting object.
Steering a 3D scene
3D steering is still steering, plus the editor:
- Scene editor — direct edits to parameters, parts and materials
- ⌥-click / follow-ups — ask the agent to reshape a part or relight a scene
- Versions — keep one shape while exploring another
- Tweaks — the sliders the object exposes for fast parameter play
What it's good at
- Product objects — a vase, a device, a package, shown from every angle
- Scene elements — a hero object for a landing page, a background form
- Parametric forms — geometry you shape by parameters, not vertices
- Concept passes — the form before it gets real modeling time
3D object · Devin · subagent · gate PASS · 24 checks
Milo, the desk robot — A wave with a rest, an anticipation, a peak, a settle — deterministic to the pixel, GLB included.
▸ the prompt that made it▾ the prompt that made it
“Model a small desk robot that waves. Squat body, big head, one eye band, three-finger hand on the waving arm. It should wave hello — rest, anticipation, raised peak, settle — on a short loop. Keep the raised hand in frame on a phone-sized viewport.”
Exporting
3D exports the scene and the model — the geometry and view for embedding or handoff — and PNG renders of the object at angles you set. The scene files stay in the project for the next edit or version.
Tip: Procedural scenes are the fast path — the parameters in
scene.design.jsonare the tweaks panel, so "more rings, tighter spin" is a slider, not a remodel. Reach for Blender when the shape gets heavier than parameters carry.