Polygons are fundamental to 3D modeling.
Every polygon is formed by at least three vertices and edges coming together to create a closed shape. Three vertices, or points, makes a triangle—tri for short. Four of them makes a quad. It’s industry standard to only use tris and quads in a mesh as much as possible. There is a term for polygons that have more edges than quads: they’re called N-Gons, and really should be avoided because they are more likely to cause artifacts in your textures and materials.
Understanding what constitutes a polygon will help you better manipulate and edit them while modeling. Let’s look more closely at the pieces of a polygon and where they fit in a 3D model’s mesh.
A vertex is the point where two edges meet and join. If you move the position of a vertex, you will also affect the position of the two edges simultaneously.
An edge appears in modeling programs as a line. An edge has two vertices, one on each end. When at least three edges join at their vertices, a polygon is formed: specifically, a triangle.
A face is the flat 2D shape created when a polygon is formed. Many polygonal modeling software will allow you to select a face specifically and change its position editing your mesh. Moving a face would of course, simultaneously move the edges and vertices that form it.
Create any shape imaginable using polygons.
The difference between high-poly, low-poly, and retopology.
When it comes to polygonal modeling, there are a few key industry terms you should be aware of.
In many industries, having 3D models with low numbers of polygons is desired. Often the term low-poly is used to describe a model that not only has a small number of polygons, but has a mesh that has been recreated or optimized to lower its poly count.