In the previous chapter, we learned that a mesh is made up of two things: a geometry (the shape) and a material (the look). Today, we're zooming in on that first piece — the one that gives our 3D object its form and structure. Geometries are the foundation of all 3D shapes in Three.js. Whether you’re building a cube, a donut, or a custom spaceship, it all starts with defining the geometry. So, let’s roll up our sleeves and explore the fascinating world of geometries in Three.js ! ---