Parametric Tools & Techniques
Rhino, Grasshopper and its plug-ins — the parametric toolkit.
This is the hands-on heart of the elective: the TOOLS. The dominant toolkit is Rhino (the NURBS modeller) with Grasshopper, its visual node-based plug-in — you wire components into a ‘definition’ that generates geometry, with no text coding. Around it sit plug-ins: Kangaroo (physics/form-finding), LunchBox (panelling), Ladybug (environment) and Weaverbird (mesh). This unit covers how to build geometrical relationships among complex shapes, and the techniques that make parametric work efficient. Try the attractor-field explorer.
Learning objectives
By the end of this unit, you will be able to — mapped to the course outcomes for Parametric Architecture & Modelling:
Explain how Rhino and Grasshopper's visual node-based definition generates geometry.
Identify the key Grasshopper plug-ins (Kangaroo, LunchBox, Ladybug, Weaverbird) and what each does.
Build geometrical relationships among complex shapes parametrically.
Use the attractor pattern to drive a field of geometry.
The toolkit
Grasshopper is visual node-based programming — the wiring is the algorithm; plug-ins extend it (Kangaroo physics, LunchBox panels, Ladybug environment, Weaverbird mesh).[4, 1]
The dominant toolkit
RHINO (Rhinoceros, by Robert McNeel & Associates) is the leading NURBS free-form modeller; GRASSHOPPER, its built-in visual programming plug-in (created by David Rutten), is where parametric design happens. You drag COMPONENTS onto a canvas and WIRE them together into a DEFINITION — a dependency graph that generates Rhino geometry live. No text code is needed: the wiring IS the algorithm. Change an input slider and the geometry regenerates. It is the de-facto standard of architectural parametric design.[4]
The attractor field
Move the attractor point and watch a field of cells scale by their distance to it — one simple rule generating a rich, controllable field, the iconic parametric exercise.
Attractor field · move the attractor
One rule — cell size ← distance to the attractor — generates the whole field. Move the pink point and the cells respond live. This is the essence of parametric design.
The techniques
Building explicit geometrical relationships is the core skill; parametric techniques boost productivity — but a definition must stay legible, like good software.[5, 4]
Wiring complex shapes
The core skill is building explicit GEOMETRICAL RELATIONSHIPS among shapes — 'this panel's size depends on its distance to that curve'; 'these louvres rotate by the sun angle'; 'this tower's floors twist by their height'. In Grasshopper these relationships are the WIRES between components. Designing parametrically is composing these relationships into a definition that captures your design intent as live, editable logic.[5]
At a glance
| Aspect | One | The other |
|---|---|---|
| Programming style | Grasshopper: visual node wiring | Text coding: not required |
| Kangaroo's job | Physics / form-finding | (LunchBox: panelling; Weaverbird: mesh) |
| Ladybug is | Myth: it does the physics | Reality: an interface to Radiance/EnergyPlus |
| Attractor field | Rule: distance → size/rotation | Result: a rich, controllable field |
| A definition | Spaghetti of wires | Should be named, grouped, legible |
Key terms
The leading NURBS free-form modeller; host for Grasshopper.
Rhino's visual node-based programming plug-in — wire components into a definition.
The Grasshopper graph of wired components that generates geometry live.
A live physics/form-finding engine for Grasshopper (Daniel Piker).
A plug-in for panelising and meshing surfaces (diagrids, triangles, hexagons).
An environmental-analysis interface in Grasshopper (sun, radiation, daylight) — engines do the physics.
A mesh subdivision/smoothing plug-in for Grasshopper.
A point/curve that a field of geometry responds to — the iconic parametric exercise.
Studio task
Using the attractor explorer, design a facade screen: place the attractor to put the largest (or smallest) openings where you want the most light or privacy, and describe in words the Grasshopper definition that would build it (curve → divide → circles → scale-by-distance → bake). Name one plug-in you would add (Kangaroo, LunchBox, Ladybug or Weaverbird) and why.
Self-assessment
1. Grasshopper lets an architect program parametric geometry by —
2. Kangaroo, a Grasshopper plug-in, is mainly used for —
3. The 'attractor' exercise demonstrates parametric design because —
Recap
References & further reading
- [1]Piker, Daniel — 'Kangaroo: Form-Finding with Computational Physics', Architectural Design 83(2), 2013.
- [4]Sakamoto, Tomoko (ed.) — From Control to Design: Parametric/Algorithmic Architecture (Actar-D, 2008); McNeel — Rhino & Grasshopper documentation.
- [5]Woodbury, Robert — Elements of Parametric Design (Routledge, 2010).
Further reading
- Robert Woodbury — Elements of Parametric Design (2010).
- Daniel Piker — Kangaroo (Architectural Design, 2013).
- Rhino / Grasshopper / LunchBox / Ladybug documentation.
Sources gathered and fact-checked June 2026. Published values vary by source, sample and method — treat as indicative and confirm against the cited standard before structural use.