Keyboard reader for Grasshopper

A prototype way of interacting with Grasshopper with the keyboard. Press any character key on the keyboard to send true/false values to Grasshopper.

It uses the Global Mouse and Keyboard Hook classes by George Mamaladze to intercept key up/down events. I have written two components that turns these key events into true/false commands – if a key is raised, ‘false’ is sent, and if pressed, ‘true’ is sent.

Keyboard reader with 6 pre-filled keys
Keyboard reader with 6 pre-filled keys

In the component above, 6 keys have been hard-coded. (I have been using this as part of video game-like WASD camera control in Rhino.) The component below accepts any character (and possibly any key on the keyboard if you’re lucky enough to find the correct character code for each key.)

Keyboard reader with any letter of the keyboard
Keyboard reader with any letter of the keyboard


To install, download the file at the bottom of this page. Unzip and copy the two files (one GHA and one DLL) into your Grasshopper components folder. To use, set up as in the images above, and remember to attach a timer with a short interval. You may need to unblock the file within Windows if you are having problems. (Right click each of the two files in Windows Explorer, click Properties, and click Unblock.)

Source code

The source code of the Grasshopper components is available at GitHub.

The classes for interacting with the keyboard must (at least for the moment) be downloaded separately, and are available here.


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