Grasshopper plugin · Rhino 8

Design the bowl. Don’t just generate it.

Antlion is a Grasshopper plugin for stadium seating bowls. It builds the stand from the start line out — sections, stands, vomitories, seats, cuts — keeps every step editable, and checks C-value sightlines continuously as you design, not after the fact.

One chain, not a black box

From the field outward, each component’s outputs match the next one’s inputs in order. Change the start line and the whole bowl follows — the seats, the cuts, the solids, the sightline maps.

Three different ways to build a section — drawn by hand, solved from a target C-value, or driven from a spreadsheet — all produce the same object. Everything downstream cannot tell which way it came.

See the workflow

Sightlines checked as you design

C-value is computed per seat and per tread band across the whole bowl, so you see where the design breaks down rather than checking one section and hoping.

Section checks draw their evidence — dimensions and sightlines on the real cut — so a number you report is a number you can defend in a meeting.

Analysis components

Bring your own curves

The presets are where you start, not where you have to stay. A field outline, the start line, section axes, hand-drawn tread lines, cut and opening curves, seat blocks and aisles can all come from your own Rhino or Grasshopper curves.

Antlion builds the bowl around them and checks the sightlines again, so you can change the shape and see what it does to every seat.

Components

Drawings and spreadsheets, both directions

Results go straight onto drawing sheets. Step heights, tread depths, tier settings and the C-value target can be read from a Google Sheets or Excel workbook and the results written back to it — change the numbers, run, and the section follows.

Works in millimeter and inch documents.

Table components

Where Antlion is going

Antlion 1.0.0 covers the seating bowl. Later versions build outward from it — first the structure and circulation around the bowl, then the facade and roof.

• Fixes come first. For the first few months after release, the work goes into fixing and refining 1.0.0. Development of 2.0.0 starts after that.
• Versions may come with their own plans. 2.0.0 and 3.0.0 may be offered as higher subscription plans, and the plans may be priced differently.
• Nothing you have moves up. A component in your plan stays in your plan — a new version never moves an existing component to a higher plan.
• Components can move down. Over time, components from a higher plan may be added to a lower one.

This is a plan, not a release schedule. What goes into each version, and when, may change.

Learn it

New to Antlion? Read these two, in this order.

1. Getting started — what you need, installing from the package manager, and registering your license.
2. Workflow — the whole chain as a map. Start here if you are wondering what order to use things in.

When you need to look something up:

• Components — every component, every port, with a diagram of where each port sits on the capsule. Generated from the plugin source for each release, and every page names the version it describes.
• Ribbon map — which panel and section each component lives in, for when you know the plugin and just want to find the thing.
• Tutorials — video walkthroughs that build a stadium bowl step by step, with chapters you can jump to.
• Troubleshooting — known symptoms, causes, and fixes.
• Changelog — what changed in each release.

Get Antlion

Antlion is distributed through Food4Rhino and the Rhino package manager. Pricing and purchase are handled there.

Antlion on Food4Rhino

The plugin itself is free to download. Components in the Util panel work without a license; the bowl, analysis and table components need one.

Use of Antlion is governed by the Antlion End User Licence Agreement; checkout asks you to accept it. How we handle personal data is set out in our privacy policy.

Report a problem

Found a bug, or something that does not behave the way the reference says it should?

Report a problem →

No account or sign-in is required. The form asks what you saw and how to reproduce it. The quickest way in is from Grasshopper: right-click License → Report a problem, which opens the form with your Antlion, Rhino and Windows versions already attached. If Antlion does not load at all, add which Rhino you run — SystemInfo in Rhino shows it. Two steps — internalising the geometry, or pasting the Debug output — usually let us find the cause without asking you anything further: how to write a report that gets fixed.

Subscription, payment and invoice questions are handled by Polar, the merchant of record for this product — use the customer portal (the link in your purchase email, or right-click License → Manage subscription) rather than the report form.

Who builds Antlion

Antlion is built and maintained by plugin.dev.lab, which works on design automation for Rhino and Grasshopper. Bugs are fixed and shipped continuously — the changelog is the record of that, and it is the honest way to judge whether a subscription is worth it.