Model with topology
TopMod builds high-genus shapes and complex geometry for 3D printing and form finding. With two decades of use by architects, designers, mathematicians and artists, it now runs in your browser and on your phone. Start from a shape or an equation and turn mathematical ideas into new forms you can render, share or 3D print.
Topology you can touch
- Don’t get it twistedHow to modelThe idea behind TopMod is simple: shape the topology first, and the geometry follows. Every tool is built from two basic moves, inserting and deleting an edge, so the model always stays one clean, closed surface. It can't tear, overlap or break, no matter how many holes, handles and twists you add. Well, maybe. Push it to the max!
- Topology optimizationDesign with mathA new way to push your 3D creativity further. These new tools generate structure from loads and supports and carve away at the material. Also included are more 3D generators: reaction-diffusion, cellular automata, branching growth, hyphae, slime mold, terrain, origami folds and wave-function-collapse pipes.
- ComplexityModel the nearly impossibleThis software models complex forms fast. Bejewel sets a cut gem on every face of a shape, each one placed, faceted and ray-traced in seconds.
- Gem CutCut real gemsRound brilliant, cushion, emerald and more, ray-traced live. The renderer mimics how real light refracts, reflects and splits into color inside a cut stone. A slice then moves down through the spinning stone, showing each layer in ASET colours: where light enters, returns and leaks.
- Study with real dataWind and stressNew advanced tools are readily available to see geometry in a new way: how air flows around a form, then how it deforms under load.
- Real world physicsSimulate physicsDrop fabric, bounce, explode, melt. Real-world physics runs right on your model, like this cloth settling over a cymatic wave and a 3D Voronoi sphere.
- GrowthGrow a slime moldNew tools are added all the time. Try these new experiments and suggest new ideas and techniques. With the open source code, you can redesign the software the way you need it to work for you.
- Fabrication toolsCut it from plywoodSlice any form into plywood layers, waffle grids, face panels or laser-cut finger joints. Every part is numbered and nested onto 4 × 8 sheets, ready to export for the CNC, like this tapered spiral shell.
- Hand controlModel with your handsCamera hand tracking selects, extrudes, zooms and orbits with simple gestures. No mouse, no touch.
New tools are added and updated all the time.Have an idea or found something to fix? Leave a comment ↗ and follow along as new updates land.
One app, two screens
- 01Top screen: look and pickThe full 3D viewport. Drag to orbit, tap a face to select it, pinch or scroll to zoom.
- 02Bottom screen: the app you knowMenu bar, toolbar, Layers, Modifiers and options, unchanged. Tool panels open down here, so they never cover the model.
- 03Built-in touch padThe open space between the toolbar and the panels steers the camera, so your thumbs never leave the lower half.
- 04Fold flat for one big canvasOpen it all the way and TopMod goes back to its single-screen layout.
Push it to the limits
Built on 20 years of TopMod research
TopMod 3D is an open source topological mesh modeler by AMAXiMAL for iPhone, iPad and the web. It grows out of the TopMod research on topological mesh modeling at Texas A&M University (Ergun Akleman and colleagues), where every operation keeps the mesh a clean, connected surface. The classic desktop release, TopMod 2.0 (2008), made these tools freely available to students, artists and researchers. Punch holes, add handles, twist and subdivide freely, and still end up with something you can render, share or 3D print.
TopMod v3.0 is developed by John Briscella of AMAXiMAL, a computational designer who has worked with Ergun Akleman on TopMod. He rebuilt TopMod to run in the browser and on iPhone and iPad, kept Akleman's topology kernel intact, and added the tools around it: layers and a non-destructive modifier stack, new primitives and generators, booleans, mesh analysis, Gem Cut and Bejewel, Aero and FEA, 3D printing and fabrication tools, hand tracking, the folding-screen layout, and embedded AI with Claude.
The Duo layout is TopMod's answer to a folding screen. Bend the phone to a half-fold and the app splits itself in two. Lay it flat again and you get one big canvas.
- Read the paper ↗TopMod: Interactive Topological Mesh Modeler · Ergun Akleman et al.
- Open source on GitHub ↗github.com/AMAXIMAL/topmod3d
- Press release ↗PDF
- Press kit ↓ZIP · 24 MB · release, feature images, Duo views, Duo reel, app icon and logos
- Video demos ↓ZIP · 24 MB · ten feature demo clips (MP4)
- Duo reel ↓MP4 · 19 MB · 1:37 · the phone opens, runs the demos and closes
- Download on the App Store ↗Free for iPhone and iPad
- Try it in your browser ↗Free, nothing to install
- Rhino 8 plug-in ↗TopMod 3D for Rhino, with a live link
Use AI Claude to model equations
Have complex mathematical equations rendered in real time. Give Claude an equation or a rule and it works through the math with you, building it in TopMod as real, editable topology.
AI agents reproduce the results step by step as live modifiers, so you can check every stage, change a value and watch the form update. It works on iPhone, iPad, the Duo and the web.
Free on the App Store
For iPhone and iPad as “TopMod — 3D Mesh Modeler”. The Duo layout ships in v3.9 and turns on by itself on a foldable screen, or any time from View ▸ Duo layout.
Have AMAXiMAL develop your next project or app
AMAXiMAL is the computational design studio of John Briscella. We build custom 3D software, iPhone and web apps, generative design tools and fabrication projects, from the first idea to the App Store, the CNC and the finished piece.
The bottom screen in this viewer is the real TopMod 3D app, not a video. The foldable iPhone is a concept model; the device and screen sizes are illustrative. MacBook Pro 16 model by jackbaeten, CC BY 4.0.
Press kit (ZIP) · Video demos (ZIP) · Duo reel (MP4) · release, screenshots, demo videos and logos
© 2026 AMAXiMAL · John Briscella