Version: 2018.2
public int subMeshCount ;


The number of sub-meshes inside the Mesh object.

Each sub-mesh corresponds to a Material in a Renderer, such as MeshRenderer or SkinnedMeshRenderer. A sub-mesh consists of a list of triangles, which refer to a set of vertices. Vertices can be shared between multiple sub-meshes. See Also: GetTriangles, SetTriangles.

using UnityEngine;

public class Example : MonoBehaviour { void Start() { Mesh mesh = GetComponent<MeshFilter>().mesh; Debug.Log("Submeshes: " + mesh.subMeshCount); } }