Meshes 101

Basic Introduction to Meshes

A mesh model is a 3D model that consists of vertices, edges and faces in 3D space. Edges are formed from vertices and together, they form flat faces. These faces come together to represent the surfaces of an object.

By varying the number of vertices, how they're arranged and density, you can arrive at a variety of surface representations.

Meshes are created by using a 3D Modelling program such as Rhinoceros 3D, Autodesk 3DS Max or Blender, but you may also model as NURBs objects and convert.

Meshes are the default 3D model standard used in the process of 3D printing. As their elements are discrete, it is easier for computers to process when converting the files into 3D printer-ready files.

Mesh Properties

Closed Mesh (Water-Tightness)

This refers to a mesh that has no holes due to missing faces, edges and/or vertices. The mesh must have an ‘inside’ and ‘outside,' defined as an enclosed volume. By extension, single surfaces are also not valid for 3D printing.

When given a colour, you can see what is 'inside' and 'outside.' Each face technically also has an orientation.

Smoothness/Resolution

As a mesh is a discretised object, smooth surfaces and details needs to be approximated by flat faces/polygons. Higher face counts leads to bigger and slower meshes that will slowdown your entire process, but may be required to capture the smoothness or the intricate details of an object.

Manifold

A manifold is an edge that is only attached to two faces. If a mesh is closed then it will have all manifold geometry. However, it is possible to attach closed geometry together so that they share an edge. These should be avoided by overlapping them properly or ensuring they don't join.