Smoothing 3D files

Question

I am trying to apply a smoothing algorithm on a .STL file.

I use Eyeshot from DevDept to load and manipulate STL files.

There is no built-in method in Eyeshot.

To apply a smoothing algorithm, I try to convert the Eyeshot entity to an entity in Geometry3DSharp because there is a built-in smoothing method but, the conversion is not possible. But the result is not as expected.

Any suggestion on how to apply a smoothing algorithm on a 3D object, please?

Here is what I try to smooth the object using Geometry3DSharp :

DMesh3 mesh = load_my_mesh_somehow();
Remesher r = new Remesher(mesh);
r.PreventNormalFlips = true;
r.SetTargetEdgeLength(0.5);
for ( int k = 0; k < 20; ++k )
    r.BasicRemeshPass();

user_1829048 · Answer

There are several smoothing algorithm. Laplacian smoothing is one of the best solutions.

Applying your own laplacian smoothing algorithme can be laborious. Instead you can use MeshlabServer to apply a perfect laplacian smoothing.

You should have necessary meshlab dlls. For that, you can install the Meshlab on the PC. When you install the Meshlab on a PC, you have all necessary dlls in the installation folder. But if you want to take only the dlls that you need for the filtering method that you want to use, you can put them in your installation folder. In this case, you should install visual C++ redistribuables (Microsoft Visual C++ 2015-2019 Redistributable (x64) - 14.26.2872) on the pc that you want to call MeshlabServer's fonctions.

Finally, you should define your .mlx file to tell to the Meshlab server which filter to apply.

Here is the content of the .mlx file for a laplacian smoothing of 6 steps :

And the C# method to call the filtering function :

    /// 
    /// Applies a laplacian smoothing filter to the given 3D object.
    /// 
    /// The path of the source 3D object
    /// The path to save the smoothed result.
    /// The path of the Meshlab dlls folder
    /// 
    public static bool LaplacianSmoothing(string input, string output, string meshlabRoot)
    {
        bool retVal = true;
        try
        {
            string strCmdText;
            string mlxPath = meshlabRoot + "LaplacianFilter.mlx";
            strCmdText = "/C " + meshlabRoot +
                @"meshlabserver " +
                @"-i " + input + " " +
                @"-o " + output + " -s " +
                mlxPath;

            System.Diagnostics.Process process = new System.Diagnostics.Process();
            System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
            startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
            startInfo.FileName = "cmd.exe";
            startInfo.Arguments = strCmdText;
            startInfo.WindowStyle = ProcessWindowStyle.Hidden;
            process.StartInfo = startInfo;


            process.Start();


            process.WaitForExit();
        }
        catch (Exception ex)
        {
            UserMethods.ParseError(ex, "SmoothFile");
            retVal = false;
        }

        return retVal;

user_5129542 · Answer

You can check to ensure you are using smooth index triangles on your mesh.

Mesh mesh = new Mesh();

Mesh smoothMesh = (Mesh)mesh.Clone();
for (int i = 0; i < smoothMesh.Triangles.Count(); i++)
{
    SmoothTriangle tST = new SmoothTriangle(smoothMesh.Triangles[i].V1, smoothMesh.Triangles[i].V2, smoothMesh.Triangles[i].V3);
    smoothMesh.Triangles[i] = tST;
}

Mesh flatMesh = (Mesh)mesh.Clone();
for (int i = 0; i < flatMesh.Triangles.Count(); i++)
{
    IndexTriangle tIT = new IndexTriangle(flatMesh.Triangles[i].V1, flatMesh.Triangles[i].V2, flatMesh.Triangles[i].V3);
    flatMesh.Triangles[i] = tIT;
}

Smoothing 3D files

2 Answers