Starting out in 3D can feel like learning a foreign language. These 3d modeling terms cover the words you will meet first: mesh, topology, UV mapping, textures and rigging. Learn them in that order and tutorials start making sense.
For the wider picture, read the guide to 3d modeling basics, which this glossary supports.
| Term | Key fact |
|---|---|
| Triangle | 3 sides |
| Quad (quadrilateral) | 4 sides |
| N-gon | More than 4 sides |
| Polygon count of game assets | Usually under 50,000 |
| Polygon count of film assets | Can reach millions |
The figures come from the Autodesk Maya help and the Meshy core concepts page. Definitions and polygon budgets can change between tools and versions, so check the source before you rely on them.
The building blocks: vertex, edge, face and mesh
Every polygon model is made from three basic components, and each has its own name. Once you know them, the rest of the vocabulary hangs off them.
- Vertex: the smallest part of a 3D model, the point of intersection between three or more edges (lines) in 3D space.
- Edge: a line that exists between two vertices.
- Face: the area bounded by three or more vertices and their associated edges. A single face is also called a polygon.
A mesh is a collection of vertices, edges and faces that define the shape of a 3D model. When many faces connect, the result is called a polygon mesh.
Most faces are either triangles or quads. Triangles have three sides and quads have four. Software such as Maya also supports n-gons, which have more than four sides, but they are less common in everyday modeling.
Topology, polygon count and optimisation terms
Topology is the arrangement and flow of polygons on a mesh surface. Clean topology, with even quads that follow the surface contours, is essential for animation and deformation. If the idea is new to you, the explainer on what is topology in 3d modeling goes into more detail.
Edge flow is the way edges run across a surface. Good edge flow lets a character bend an arm or change expression and deform smoothly, without pinching.
Once a model exists, you will often need to make it lighter. These are the terms for that:
- Polygon count (or poly count): the number of polygons in a mesh. Lower counts give better performance.
- Low poly: a modeling style that uses few polygons, popular in games and stylized art.
- Decimation: a function that reduces the number of polygons. It can cut processing needs sharply, but may not give ideal topology.
- Retopology: rebuilding a mesh with cleaner, more efficient polygon flow for animation, games or further editing.
- LOD (level of detail): swapping a model for simpler versions as it moves further from the camera.
Budgets depend on the target. Game assets usually stay under 50,000 polygons, while film assets can reach millions, according to the Meshy documentation.
Texturing, materials and shading terms
A bare mesh is only a shape. These terms describe how it gets colour, detail and light.
- Texture: an image mapped to the surface of your model’s materials.
- Material: the optical properties of a surface, such as colour and shininess. One model can use several materials.
- Shader: a function that determines how a material’s appearance varies with the angle of the light.
- UV mapping: wrapping a 2D texture onto a 3D surface. U and V are used because X, Y and Z already name the model’s axes.
- UV unwrapping: flattening the polygons of your model into a 2D layout so a texture can fit.
Maya’s documentation confirms that polygon models are texture mapped using UV coordinates, so this step appears in almost every workflow.
Maps that fake detail
A normal is the direction a vertex points towards, and lighting depends on it. Several map types use that idea to add detail without extra polygons.
- Normal map: adds surface detail by bending the normals, without adding more polygons.
- Bump map: creates the illusion of depth by changing how the renderer and lights see the surface.
- Displacement map: physically moves vertices, giving a greater sense of depth and detail.
- Ambient occlusion (AO): darkens crevices and corners by occluding ambient light.
PBR and baking
PBR (physically based rendering) is a method of shading that models how light interacts with real surfaces. In Meshy’s description, PBR textures are albedo, normal, roughness and metallic maps. The albedo map is the base colour without lighting or shadow information.
Baking calculates light and shadow information into a model’s geometry or texture. Once an effect is baked in, it cannot be updated dynamically, unless it was baked into a texture. A MatCap, short for material capture, is a quick way to apply material and reflection information so you can check a model’s shape and normals.
Rigging and animation terms
Static models need no skeleton. If you want a character to move, you will meet these words.
- Bones: together they form a skeleton, also called an armature, used to manipulate a mesh.
- Rig: the controls added to a model to make animating easier.
- Rigging: adding a skeleton to a mesh so it can be animated.
- Skinning: binding a mesh to a skeleton, which defines how vertices deform when bones move.
Rigging depends on good topology, which is one reason the two topics are so often taught together.
File formats and output terms
Finishing a model means exporting it in a format that suits where it will be used. The render is the process of producing an image from 3D data stored in a computer.
- STL: stores only geometry, with no colour or texture. It is the standard format for 3D printing.
- FBX: a proprietary Autodesk format widely used to exchange assets between game engines such as Unity and Unreal and other creation tools.
- GLB and glTF: open standards. GLB is the binary version, a single file with embedded textures, while glTF is the JSON version made of several files.
- USDZ: the compressed version of USD that Apple uses for AR Quick Look.
- Watertight mesh: a closed mesh with no holes or open edges, which 3D printing requires.
- Point cloud: a set of data points in 3D space, generally produced by 3D scanners.
- WebGL: JavaScript code for rendering 2D and 3D graphics inside a browser without plug-ins.
These descriptions come from the Meshy glossary and the Sketchfab glossary. Each tool names its own export options, so confirm the format list in your software.
Which terms should you learn first?
Start with the mesh and its components, because every other term refers back to them. Next comes topology and polygon count, then UV mapping and textures, and rigging last.
- Vertex, edge, face, polygon and mesh.
- Triangles, quads, topology and polygon count.
- UV mapping, textures, materials and normal maps.
- Rigging, skinning and animation.
- Export formats for your target, such as games, the web or printing.
Words stick when you use them on a real model. For a study plan, see this guide on how to learn 3d modeling.
Frequently asked questions
What is the difference between a polygon, a face and a mesh?
Show answer
A polygon is a shape with three or more connected vertices, and an individual polygon is commonly called a face. A mesh is the whole collection of vertices, edges and faces that defines the model.
Why is it called UV mapping?
Show answer
The letters U and V name the axes of the 2D texture. They are used because X, Y and Z are already taken by the axes of the 3D object in space.
Does a normal map add polygons to a model?
Show answer
No. A normal map adds surface detail by bending the normals, so it creates the illusion of a high-resolution model without extra polygons or processing needs.
How many polygons should a game model have?
Show answer
It depends on the platform and the asset. Meshy’s documentation says game assets usually stay under 50,000 polygons, but treat that as a rough guide and check your engine’s own limits.
