[Unity3D] 유니티 메시를 STL(format)으로 변환하여 저장 하기.

참고 링크 https://en.wikipedia.org/wiki/STL_(file_format)

ASCII STL[edit]

An ASCII STL file begins with the line

solid name

where name is an optional string (though if name is omitted there must still be a space after solid). The file continues with any number of triangles, each represented as follows:

facet normal ni nj nk    outer loop        vertex v1<sub style="line-height: 1; font-size: 11.2px;">x</sub> v1<sub style="line-height: 1; font-size: 11.2px;">y</sub> v1<sub style="line-height: 1; font-size: 11.2px;">z</sub>        vertex v2<sub style="line-height: 1; font-size: 11.2px;">x</sub> v2<sub style="line-height: 1; font-size: 11.2px;">y</sub> v2<sub style="line-height: 1; font-size: 11.2px;">z</sub>        vertex v3<sub style="line-height: 1; font-size: 11.2px;">x</sub> v3<sub style="line-height: 1; font-size: 11.2px;">y</sub> v3<sub style="line-height: 1; font-size: 11.2px;">z</sub>    endloopendfacet

where each n or v is a floating-point number in sign-mantissa-"e"-sign-exponent format, e.g., "2.648000e-002" (noting that each v must be non-negative). The file concludes with

endsolid name

The structure of the format suggests that other possibilities exist (e.g., facets with more than one "loop", or loops with more than three vertices). In practice, however, all facets are simple triangles.

White space (spaces, tabs, newlines) may be used anywhere in the file except within numbers or words. The spaces between "facet" and "normal" and between "outer" and "loop" are required.^[6]

 

위와 같이 아스키코드로 제작 하였습니다.

public void ModelSaveToSTL()
    {
        List<Vector3> _Vertex = new List<Vector3>();
        List<Vector3> _Nomal = new List<Vector3>();
        StreamWriter sw = new StreamWriter(pathForDocumentsFile("sample.stl"));
        List<GameObject> _ObjectList = GameObject.FindGameObjectWithTag("Manager").GetComponent<ObjectManager>().Objects;
        sw.WriteLine("solid ModelSTL");     //Model Name
 
        int index = 0;
        foreach (GameObject G in _ObjectList)
        {
            foreach (int _tri in G.GetComponent<MeshFilter>().mesh.triangles)
            {
                _Vertex.Add(G.GetComponent<MeshFilter>().mesh.vertices[_tri] + G.transform.position);
                _Nomal.Add(G.GetComponent<MeshFilter>().mesh.normals[_tri]);
            }
            index += G.GetComponent<MeshFilter>().mesh.triangles.Length/3;
        }
        sw.WriteLine(index.ToString());
        int Nomalcount = 0;
        int Vertexcount = 0;
        for (int i = 0; i < index; i++)
        {
            Vector3 Vt = ((_Nomal[Nomalcount++] + _Nomal[Nomalcount++] + _Nomal[Nomalcount++]) / 3.0f);
            sw.WriteLine("facet normal "+
                Vt.x.ToString() + " " +
                Vt.y.ToString() + " " +
                Vt.z.ToString()
                );  // Nomal
            sw.WriteLine("outer loop"); 
            sw.WriteLine("vertex " +
                _Vertex[Vertexcount].x.ToString() + " " +
                _Vertex[Vertexcount].y.ToString() + " " +
                _Vertex[Vertexcount].z.ToString()
                );  //Vertex01
            Vertexcount++;
            sw.WriteLine("vertex " +
                _Vertex[Vertexcount].x.ToString() + " " +
                _Vertex[Vertexcount].y.ToString() + " " +
                _Vertex[Vertexcount].z.ToString()
                ); //Vertex02
            Vertexcount++;
            sw.WriteLine("vertex " +
                _Vertex[Vertexcount].x.ToString() + " " +
                _Vertex[Vertexcount].y.ToString() + " " +
                _Vertex[Vertexcount].z.ToString()
                ); //Vertex03
            Vertexcount++;
            sw.WriteLine("endloop"); 
            sw.WriteLine("endfacet"); 
        }
        sw.WriteLine("endsolid ModelSTL"); 
        sw.Flush(); 
        sw.Close();
        Debug.Log("저장 완료");
    }
 

직접 저장해보고 STL 뷰어로 확인하니 이상없었습니다.