The Grasshopper Primer (EN)

Third Edition V3.3

Primer Release Cover

Grasshopper is a graphical algorithm editor tightly integrated with Rhino’s 3-D modeling tools, allowing designers to build form generators from the simple to the awe-inspiring.


You have just opened the third edition of the Grasshopper Primer. This primer was originally written by Andrew O. Payne of Lift Architects for Rhino4 and Grasshopper version 0.6.0007 which, at the time of its release, was a giant upgrade to the already robust Grasshopper platform. We now find ourselves at another critical shift in Grasshopper development, so a much needed update to the existing primer was in order. We are thrilled to add this updated, and now web-based, primer to the many amazing contributions put forth by Grasshopper community members.

With an already excellent foundation from which to build, our team at Mode Lab went to work designing and developing the look and feel of the third edition. This revision provides a comprehensive guide to the most current Grasshopper build, version 0.90076, highlighting what we feel are some of the most exciting feature updates. The revised text, graphics, and working examples are intended to teach visual programming to the absolute beginner, as well as provide a quick introduction to Generative Design workflows for the seasoned veteran. It is our goal that this primer will serve as a field guide to new and existing users looking to navigate the ins and outs of using Grasshopper in their creative practice.

This primer introduces you to the fundamental concepts and essential skill-building workflows to effectively use Grasshopper. Foundations is the first volume in a forthcoming collection of Grasshopper primers. Here's what you can expect to learn from the primer:

  • Introduction - What is Grasshopper and how is it being used?
  • Hello Grasshopper - Make your first definition
  • Anatomy of a Grasshopper Definition - What makes up a definition?
  • Building Blocks of Algorithms - Start simple and build complexity
  • Designing with Lists - What's a list and how do I manage them?
  • Designing with Data Trees - What's a data structure and what do they mean for my process?
  • Appendix - References and Working files for continued exploration

We hope that at the very least this primer will inspire you to begin exploring the many opportunities of programming with Grasshopper. We wish you the best of luck as you embark on this journey.


The Grasshopper Primer is an open source project, initiated by Bob McNeel, Scott Davidson, and the Grasshopper Development team at Robert McNeel & Associates.

Mode Lab authored the Third Edition of the primer.

Mode Lab Logo

If you would like to contribute to this project, check out the github project wiki to get started (


A special thanks to David Rutten for the endless inspiration and invaluable work pioneering Grasshopper. We would also like to thank Andrew O. Payne for providing the assets from which this work initiated. Lastly, many thanks to Bob McNeel and everyone at Robert McNeel & Associates for their generous support over the years.



Rhino 5.0 is the market leader in industrial design modeling software. Highly complicated shapes can be directly modeled or acquired through 3D digitizers. With its powerful NURBS based engine Rhino 5.0 can create, edit, analyze, and translate curves, surfaces, and solids. There are no limits on complexity, degree, or size.


For designers who are exploring new shapes using generative algorithms, Grasshopper is a graphical algorithm editor tightly integrated with Rhino’s 3D modeling tools. Unlike RhinoScript or Python, Grasshopper requires no knowledge of the abstract syntax of scripting, but still allows designers to build form generators from the simple to the awe inspiring.


The Grasshopper forum is very active and offers a wonderful resource for posting questions/answers and finding help on just about anything. The forum has categories for general discussion, errors & bugs, samples & examples, and FAQ.

The Common Questions section of the Grasshopper site contains answers to many questions you may have, as well as helpful links:

For more general questions pertaining to Rhino3D be sure to check out the McNeel Forum powered by Discourse.


The Grasshopper Primer is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported license. The full text of this license is available here: