3D Inflatable Origami Star – Stellated Octahedron Tutorial (Step-by-Step Guide)

Overview

The Stellated Octahedron (Origami Inflatable) is a classic geometric origami model folded from a single square sheet of paper. Through a structured sequence of pre-creases and a waterbomb-style collapse, the flat sheet transforms into a three-dimensional form with eight sharp, pyramidal points.

Once inflated, the model takes on a clean, faceted appearance, where each triangular face can be refined by sharpening the creases. This final shaping step enhances the definition of the pyramids and gives the model its characteristic sculptural look.

This version is based on the original design by Sam Ciulla, with a refined diagram layout for improved clarity and precision.

Result

Note on Geometry

Strictly speaking, this model is not a true stellated octahedron (Stella Octangula). In the classical geometric construction, the stellation of a regular octahedron produces pyramidal extensions whose faces are equilateral triangles, each with internal angles of 60°, preserving the symmetry of the regular tetrahedra involved.

In contrast, this origami model is constrained by a square reference grid, and its pyramidal faces are formed from right isosceles triangles (45°–45°–90°). Consequently, the resulting solid does not satisfy the conditions of a regular stellation: edge lengths, face angles, and dihedral angles differ from those of the canonical form.

From a geometric standpoint, the model is better described as an approximate or pseudo-stellated octahedral form, sharing the same combinatorial structure (eight protruding pyramidal units) but lacking the metric properties of a true stellated octahedron.

Key Features

- Single-sheet origami model  
- Inflatable structure  
- Eight-pointed geometric form  
- Based on Sam Ciulla’s design  

Tags

origami, inflatable origami, stellated octahedron, geometric origami, polyhedral origami, single-sheet origami, sam ciulla, waterbomb base, origami diagram