Unreason3D

Unreason3D

The Unreason3D modeler: a NURBS torus under procedural noise in the perspective viewport, the command line and tool column at the left, properties folded to its rail at the right.

A NURBS-based unproduct modeler

Curves, surfaces, solids and SuperBs - one workspace, in a browser tab.

Launch Unreason3D Any current browser. Rendre, the renderer, needs WebGPU.
Build 00001-395, 2026-10-30

Short videos of it in use are on YouTube.

What it is

Not exactly a parametric solid modeler, and not a surface modeler or a mesh SubD modeler either. Pieces of each, bashed and flowing together into one workshop.

Unreason-able things

Things mature modelers also do

  • NURBS curves and surfaces. Degree, knots, continuity.
  • Loft, sweep, revolve, blend, fillet…
  • Trims, splits and solid booleans, the booleans still in progress.
  • Parametric history, and undo that follows it.
  • Rhino .3dm in and out. partial, for now

Things others typically don't

  • Implicit and explicit history at once — the model and the nodes that control it are two live views of one graph.
  • Linked copy-paste by default. Edit the source and the copies follow, until you bake one loose.
  • Polytools. One Primitive is a sphere or a cube or a torus, as NURBS or as SuperBs.
  • SubD and NURBS as equals in one kernel. A SuperB resolves back to NURBS, creases and all.
  • Puff. Draw a closed outline, holes and all, and it inflates into an editable SuperB.
  • Dynamic Bond. Hang a SuperB from a surface and let it settle. Move the surface and it follows.

Things it doesn't have

  • A plugin system. It is open source — write the tool into your copy.
  • A node system as open-ended as Grasshopper. Fewer nodes, each doing more.
  • Real-time collaboration, accounts, cloud anything.
This is not production software

A research project and a teaching tool, made by one quirky person and his rational LLM. Do not use it for important, safety-critical or government regulated work, or for anything you cannot afford to lose. It has bugs we know about, and probably many more we don't.