STL-file and vertex normals

Unity Engine
1

Hi, all.

I am new in Unity3d, and mayble I’ve missed something but …

I need to import and stl-file into unity3d, so I wrote this code:

using System.IO;
using UnityEngine;
using System.Collections.Generic;

/// <summary>
/// Class adds me an ability to import *.stl files
/// </summary>
// ReSharper disable CheckNamespace
public class StlReader : MonoBehaviour {
// ReSharper restore CheckNamespace
    /// <summary>
    /// The number of the maximum vertexes in model
    /// </summary>
    protected static int MaxVertexCount = 64500;

    /// <summary>
    /// Contains the whole model triangles count
    /// </summary>
    protected uint TrianglesCount { get; set; }

    /// <summary>
    /// List of all imported meshes
    /// </summary>
    protected List<Mesh> Meshes = new List<Mesh>(); 

    /// <summary>
    /// Reads the file and creates meshes within 65 000 of triangles
    /// </summary>
    /// <param name="fileName">name of the file</param>
    /// <returns>List of meshes</returns>
    public List<Mesh> Read(string fileName) {
        var bytes = System.IO.File.ReadAllBytes(fileName);
        var reader = new BinaryReader(new MemoryStream(bytes));
        reader.ReadBytes(80);

        var trianglesCount = reader.ReadUInt32();
        TrianglesCount = trianglesCount;
        Debug.Log(trianglesCount);

        var vertices = new List<Vector3>();
        var triangles = new List<int>();
        var triangle = 0;
        var items = new Dictionary<string, Vector3>();
        
        for (var i = 0; i < trianglesCount; i++){
            // the normal
            reader.ReadSingle();
            reader.ReadSingle();
            reader.ReadSingle();

            var vertex1 = new Vector3(reader.ReadSingle(), reader.ReadSingle(), reader.ReadSingle());
            var vertex2 = new Vector3(reader.ReadSingle(), reader.ReadSingle(), reader.ReadSingle());
            var vertex3 = new Vector3(reader.ReadSingle(), reader.ReadSingle(), reader.ReadSingle());
            
            vertices.Add(vertex1);
            vertices.Add(vertex2);
            vertices.Add(vertex3);
            
            triangles.Add(triangle++);
            triangles.Add(triangle++);
            triangles.Add(triangle++);

            reader.ReadUInt16(); // byte count

            if (vertices.Count <= MaxVertexCount - 1){
                continue;
            }

            AddMesh(vertices, triangles);

            vertices.Clear();
            triangles.Clear();
            items.Clear();
            triangle = 0;
        }

        if (vertices.Count > 0) {
            AddMesh(vertices, triangles);
        }

        return Meshes;
    }

    /// <summary>
    /// Adds new mesh to the list
    /// </summary>
    /// <param name="vertices"></param>
    /// <param name="triangles"></param>
    protected void AddMesh(List<Vector3> vertices, List<int> triangles) {
        var mesh = new Mesh {
            vertices = vertices.ToArray(),
            triangles = triangles.ToArray()
        };
       

        mesh.RecalculateNormals();
        mesh.Optimize();
        Meshes.Add(mesh);
    }
}

all is quite simple except the quality of the model :frowning:

Take a look:
http://www.freeimagehosting.net/8jwiu

As you see, there is no smooth :((

I read about the vertex normals, but I cannot make them work, because size of normals array should be the same as vertex array.

Maybe you have some ideas, how I can make model smooth?

Any help will be appreciated, thanks!

2

Hello, are you still on this topic?
Are you sure that the STL file was smooth to being with?
The normals, in the STL file, relate to the triangle, so you are expected to to set the same normal to each vertex of the triangle, or you have merge some vertices.
Have you progressed since on this?