In geometry, the excavated dodecahedron is a star polyhedron that looks like a dodecahedron with concave pentagonal pyramids in place of its faces. In this short tutorial video, I am modeling an excavated dodecahedron in the Rhinoceros software. I use basic drawing and modeling commands. I aim to introduce this skill to beginner-level architects and designers. As the name suggests, this process includes the construction of the dodecahedron first. Then, the pentagonal faces of this polyhedron were “excavated” to the interior side. Five regular triangles emerge on every pentagon. Although it looks a bit boring, this polyhedron is useful as an alternative exercise for stellation and stellated polyhedra.

In this video series, I present a variety of in-class exercises from my first-year Architectural Geometry course. We study Euclidean constructions, basic drawing, and transformation commands using Rhinoceros software. In addition to these basics, I study introductory fractals, regular and semi-regular tessellations, patterns, modeling, and unrolling polyhedra. These concise drawing exercises benefit junior architects, interior designers, industrial designers, and enthusiasts from other disciplines. I’ll share exercises and tutorials weekly on my blog and other platforms. So, today’s exercise is modeling an excavated dodecahedron.

The software used in this course is Rhinoceros 3d (www.rhino3d.com). However, if you want to find out more and see the whole list of this video series, you can check my YouTube channel at www.youtube.com/@designcodingnet and my blog at: www.designcoding.net/. You can also check my Instagram page at www.instagram.com/designcodingnet/. The music of this video is ‘Signal to Noise’ by Scott Buckley (CC-BY 4.0). www.scottbuckley.com.au