Convert mesh to stl/obj/fbx in runtime

Question

I am looking for a way to export a mesh into stl/obj/fbx format at runtime and save it on local files of an Android phone.

How do I do this? I am willing to use a plugin(free/paid) if it exist.

Answer 1

This is really complicated since you have to read the specifications for each each format (stl/obj/fbx) and understand them in order to make one yourself. Luckily, there are many plugins out there already that can be used to export Unity mesh to stl, obj and fbx.

FBX:

UnityFBXExporter is used to export Unity mesh to fbx during run-time.

public GameObject objMeshToExport;

void Start()
{
    string path = Path.Combine(Application.persistentDataPath, "data");
    path = Path.Combine(path, "carmodel"+ ".fbx");

    //Create Directory if it does not exist
    if (!Directory.Exists(Path.GetDirectoryName(path)))
    {
        Directory.CreateDirectory(Path.GetDirectoryName(path));
    }

    FBXExporter.ExportGameObjToFBX(objMeshToExport, path, true, true);
}

---

OBJ:

For obj, ObjExporter is used.

public GameObject objMeshToExport;

void Start()
{
    string path = Path.Combine(Application.persistentDataPath, "data");
    path = Path.Combine(path, "carmodel" + ".obj");

    //Create Directory if it does not exist
    if (!Directory.Exists(Path.GetDirectoryName(path)))
    {
        Directory.CreateDirectory(Path.GetDirectoryName(path));
    }

    MeshFilter meshFilter = objMeshToExport.GetComponent<MeshFilter>();
    ObjExporter.MeshToFile(meshFilter, path);
}

---

STL:

You can use the pb_Stl plugin for STL format.

public GameObject objMeshToExport;

void Start()
{
    string path = Path.Combine(Application.persistentDataPath, "data");
    path = Path.Combine(path, "carmodel" + ".stl");

    Mesh mesh = objMeshToExport.GetComponent<MeshFilter>().mesh;

    //Create Directory if it does not exist
    if (!Directory.Exists(Path.GetDirectoryName(path)))
    {
        Directory.CreateDirectory(Path.GetDirectoryName(path));
    }


    pb_Stl.WriteFile(path, mesh, FileType.Ascii);

    //OR
    pb_Stl_Exporter.Export(path, new GameObject[] { objMeshToExport }, FileType.Ascii);
}