Utility class for computing mesh UVs.
This class allows you to compute UVs for procedurally generated meshes. Computing UVs is also called "unwrapping".
Additional resources: Mesh class, Generating Lightmap UVs.
| GeneratePerTriangleUV | 将生成带有默认设置的每个三角形的 UV（每个三角形 3 个 UV）。 |
| GenerateSecondaryUVSet | Compute a unique UV layout for a Mesh, and store it in Mesh.uv2. |