private void AlignNormals()
{
using (var t = new ScopeTimer("Mesh.AlignNormals"))
{
var alignedNormals = new Vector3[Vertices.Count];
foreach (var tri in Triangles)
{
UpdateNormal(ref alignedNormals, (int)tri.I1, (int)tri.In1);
UpdateNormal(ref alignedNormals, (int)tri.I2, (int)tri.In2);
UpdateNormal(ref alignedNormals, (int)tri.I3, (int)tri.In3);
}
Normals = alignedNormals.ToList();
}
}
public bool Load(string filename, bool fromResource)
{
Vertices.Clear();
Normals.Clear();
Colors.Clear();
Triangles.Clear();
UV.Clear();
try
{
using (var t = new ScopeTimer("Mesh.Load"))
{
if (fromResource)
{
var assembly = typeof(Mesh).GetTypeInfo().Assembly;
using (var fileStream = assembly.GetManifestResourceStream(filename))
{
LoadMeshStream(fileStream);
}
}
else
{
if (File.Exists(filename) == false)
{
return(false);
}
using (var fileStream = File.OpenRead(filename))
{
LoadMeshStream(fileStream);
}
}
}
}
catch (Exception exp)
{
Debug.WriteLine("Mesh.Load exp: " + exp);
return(false);
}
Debug.WriteLine($"Loaded with {Vertices.Count} Vertices, {Normals.Count} Normals, {Colors.Count} Colors, {Triangles.Count} Triangles");
return(true);
}
private static Dictionary <string, Material> ParseMtlFile(string basePath, string mtlFileName)
{
Dictionary <string, Material> materials = new Dictionary <string, Material>();
using (var timer = new ScopeTimer($"Parse MTL File: {mtlFileName}"))
{
using (var fileStream = File.OpenRead(Path.Combine(basePath, mtlFileName)))
{
using (var streamReader = new StreamReader(fileStream, Encoding.UTF8, true, 4096))
{
try
{
string currentTextureName = null;
string line = null;
Material currentMaterial = null;
while ((line = streamReader.ReadLine()) != null)
{
string[] tokens = line.Split(' ');
switch (tokens[0])
{
case "newmtl":
if (tokens.Length != 2)
{
throw new Exception("New material declarations must have exactly 2 tokens.");
}
currentMaterial = new Material();
currentTextureName = tokens[1];
materials.Add(currentTextureName, currentMaterial);
break;
case "map_Kd":
if (tokens.Length != 2)
{
throw new Exception("Material path lines must have exactly 2 tokens.");
}
if (currentMaterial == null)
{
throw new Exception("No current material defined.");
}
currentMaterial.TextureFileName = tokens[1];
break;
default:
break;
}
}
}
catch (Exception e)
{
Debug.WriteLine($"Failed to parse {mtlFileName}. Exception: {e.Message}");
}
}
}
}
return(materials);
}
/// <summary>
/// Loads an OBJ file and its related textures (if present) into this Mesh object.
/// </summary>
/// <param name="path">The full path of the OBJ file.</param>
/// <returns>True if the OBJ file was successfully parsed, false if something went wrong.</returns>
public bool Load(string path)
{
if (IsLoaded && Filename == path)
{
return(true);
}
if (!File.Exists(path))
{
return(false);
}
ClearAll();
string objFileName = Path.GetFileName(path);
string basePath = Path.GetDirectoryName(path);
float minX, minY, minZ;
minX = minY = minZ = float.MaxValue;
float maxX, maxY, maxZ;
maxX = maxY = maxZ = float.MinValue;
using (var t = new ScopeTimer($"Mesh.Load: {objFileName}"))
{
using (var fileStream = File.OpenRead(Path.Combine(basePath, objFileName)))
{
using (var streamReader = new StreamReader(fileStream, Encoding.UTF8, true, 4096))
{
try
{
string line = null;
bool allIndicesAreAligned = true;
Geometry currentGeometry = new Geometry();
while ((line = streamReader.ReadLine()) != null)
{
if (string.IsNullOrWhiteSpace(line) || line.Length < 2)
{
continue;
}
var tokens = line.Split(' ');
switch (tokens[0])
{
// Mtl File Reference
case "mtllib":
if (tokens.Length > 2)
{
throw new Exception("MTL file references must have only 2 tokens.");
}
Materials = ParseMtlFile(basePath, tokens[1]);
break;
// Texture Reference
case "usemtl":
if (tokens.Length > 2)
{
throw new Exception("Texture references must have only 2 tokens.");
}
currentGeometry = new Geometry(tokens[1]);
Geometries.Add(currentGeometry);
break;
// Vertex
case "v":
if (tokens.Length != 4 && tokens.Length != 7)
{
throw new Exception("Vertices must have either 4 or 7 tokens.");
}
Vector3 newVertex = new Vector3(float.Parse(tokens[1]), float.Parse(tokens[2]), float.Parse(tokens[3]));
newVertex = newVertex.ConvertBetweenCoordinateSystems();
Vertices.Add(newVertex);
minX = Math.Min(minX, newVertex.X);
minY = Math.Min(minY, newVertex.Y);
minZ = Math.Min(minZ, newVertex.Z);
maxX = Math.Max(maxX, newVertex.X);
maxY = Math.Max(maxY, newVertex.Y);
maxZ = Math.Max(maxZ, newVertex.Z);
if (tokens.Length == 7)
{
Colors.Add(new Color(float.Parse(tokens[4]), float.Parse(tokens[5]),
float.Parse(tokens[6])));
}
break;
// Normal
case "vn":
if (tokens.Length != 4)
{
throw new Exception("Vertex normals must have exactly 4 tokens.");
}
Vector3 newNormal = new Vector3(float.Parse(tokens[1]), float.Parse(tokens[2]), float.Parse(tokens[3]));
newNormal = newNormal.ConvertBetweenCoordinateSystems();
Normals.Add(newNormal);
break;
// Texture Coordinates (UV)
case "vt":
if (tokens.Length != 3)
{
throw new Exception("Texture coordinates must have exactly 3 tokens.");
}
UV.Add(new Vector2(float.Parse(tokens[1]), 1.0f - float.Parse(tokens[2])));
break;
// Face
case "f":
if (tokens.Length != 4)
{
throw new Exception("Every face must have exactly 4 tokens.");
}
// [0] = Vertex Index, [1] = Texture Coordinate (UV), [2] = Normal Index
var v1 = tokens[1].Split('/');
var v2 = tokens[2].Split('/');
var v3 = tokens[3].Split('/');
// Each face token is a triplet, with exactly 3 sub-tokens
if (v1.Length != 3 || v2.Length != 3 || v3.Length != 3)
{
throw new Exception("Every face token must be a triplet with exactly 3 sub-tokens.");
}
// OBJ indexing starts at 1, so subtract 1 for each to get correct list index
uint i1 = uint.Parse(v1[0]) - 1;
uint iu1 = uint.TryParse(v1[1], out uint uv1) ? uv1 - 1 : 0;
uint in1 = uint.Parse(v1[2]) - 1;
uint i2 = uint.Parse(v2[0]) - 1;
uint iu2 = uint.TryParse(v2[1], out uint uv2) ? uv2 - 1 : 0;
uint in2 = uint.Parse(v2[2]) - 1;
uint i3 = uint.Parse(v3[0]) - 1;
uint iu3 = uint.TryParse(v3[1], out uint uv3) ? uv3 - 1 : 0;
uint in3 = uint.Parse(v3[2]) - 1;
Triangle tri = new Triangle(i1, iu1, in1, i2, iu2, in2, i3, iu3, in3);
if (!tri.IsNormalAligned)
{
allIndicesAreAligned = false;
}
tri.ConvertBetweenCoordinateSystems();
currentGeometry.Triangles.Add(tri);
TriangleCount++;
break;
default:
break;
}
}
// If <= 1 texture was used, it won't have been added while parsing (no "usemtl" defined in OBJ)
if (currentGeometry.MaterialName == Geometry.DefaultMaterialName)
{
Geometries.Add(currentGeometry);
}
if (!allIndicesAreAligned)
{
AlignNormals();
}
// Check to make sure the mesh is valid
if (Vertices.Count != Normals.Count)
{
throw new Exception("Vertex count doesn't not match normal count.");
}
if (Colors.Count > 0 && Colors.Count != Vertices.Count)
{
throw new Exception("Color count does not match vertex count.");
}
foreach (var g in Geometries)
{
foreach (var tri in g.Triangles)
{
if (tri.I1 > Vertices.Count || tri.I2 > Vertices.Count || tri.I3 > Vertices.Count)
{
throw new Exception("Triangle vertex index out of bounds.");
}
if (tri.In1 > Normals.Count || tri.In2 > Normals.Count || tri.In3 > Normals.Count)
{
throw new Exception("Triangle normal index out of bounds.");
}
if (UV.Count > 0 && !(tri.Iu1 < UV.Count && tri.Iu2 < UV.Count && tri.Iu3 < UV.Count))
{
throw new Exception("Triangle uv index out of bounds.");
}
}
}
}
catch (Exception e)
{
ClearAll();
Debug.WriteLine($"Failed to parse {objFileName}. Exception: {e.Message}");
return(false);
}
}
}
}
BoundingBox = new BoundingBox(new Vector3(minX, minY, minZ), new Vector3(maxX, maxY, maxZ));
Debug.WriteLine($"Mesh loaded with {Vertices.Count} Vertices, {Normals.Count} Normals, {UV.Count} UV's, {Colors.Count} Colors, {TriangleCount} Triangles, {Geometries.Count} Geometries");
IsLoaded = true;
Filename = path;
return(true);
}
