Cactus Tower Recreation in Grasshopper

Cactus Tower is an iconic set of school residential buildings located in central Copenhagen. Designed by renowned architecture firm BIG, it features a distinctive circular layout with rotated floors. In this step-by-step tutorial, we will show you how to recreate the Cactus Tower in Grasshopper.

Overview of Cactus Tower

Cactus Tower consists of 8 identical apartment modules arranged in a circle. Each module contains 2 apartments and a sub-balcony.

To start recreating the project in Grasshopper, we first create a 16-sided polygon representing the floor plan. Since there are 2 apartments per module, we multiply the base value of 8 sides by 2 to get 16 sides.

Next, we draw a bounding box that the 16-sided polygon fits into perfectly to get a neat square surface. This will be our base floor plate.

Rotating and Stacking Floors

A key feature of the tower is the rotated floors. To achieve this in Grasshopper, we first calculate the rotation angle.

The floors rotate in increments of the angle per module (45 degrees) divided by the number of apartments per module. For 2 apartments per module, each floor rotates 22.5 degrees relative to the floor below.

We create a shuffled list of 1 and -1 values, multiply them by the rotation angle, and add them cumulatively to get the final rotation angles.

After rotating the floor plates, we stack and extrude them to create the 3D forms. The glass façade is created by offsetting the floor polygon and lofting surfaces between floors.

Creating Walls

To make walls, we extract corner points of each floor polygon and connect them to the center. After trimming and offsetting, these lines become the wall edges.

The key is to loft lines from input A with lines from input B that are 1 level lower. This produces surfaces between each floor level to create the walls.

Capping and patching generates closed wall Brep geometry. The result is walls for Cactus Tower in Grasshopper!

Adding Details

In the complete tutorial available to our Patreon supporters, we take the project further by:

• Converting glass to panelized geometry
• Flattening walls
• Adding railings to balconies

We also cover advanced techniques like importing realistic trees and people from Chaos Cosmos into Grasshopper for rendering.

Recreate Iconic Architecture with Grasshopper

With the techniques covered in this tutorial, you can recreate the Cactus Tower along with other famous architecture in Grasshopper.

The step-by-step breakdown makes even complex forms like rotated and stacked floors achievable. You’ll also learn strategies for creating walls and adding details like railings.

To access the full extended tutorial and all source files, check out our Patreon page. We create tutorials like this regularly, so your support allows us to continue producing helpful content.

Recreating architecture from BIG and other top firms will level up your Grasshopper skills. Try out the techniques from this Cactus Tower tutorial on your next parametric modeling project!