Imported Model has more vertices in Unity than in other Editors

Questions & Answers
1

When I import a model that has texture mapping on it, the vertices count is different from the editors (tried Blender, Cinema4D and MED) I did the model in.
I tried to import in different formats (fbx, obj, c4d) but everytime I got the same result - more vertices in Unity than in the editor.
However, when I import the model before I apply texture mapping to it, I got no problem and the model has the same number.

What does affect this and how can I avoid this?

2

In any realtime engine, each vertex can have exactly one of each of the following:

  • XYZ coordinates (obviously)
  • UV coordinates
  • Vertex normal
  • Vertex tangent
  • material ID

If any vertex needs multiples of any of these (for example because there is a seam in the UVs or a hard edge between two polygons) this vertex is split on import.