internal static Model LoadFromFile(string path)
{
Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.InvariantCulture;
ObjModel result = ObjModel.Load(@"models\sponza.obj");
List<MeshVertex> meshVertices = new List<MeshVertex>();
Dictionary<string, Texture> textures = LoadMTLTextures(result.Materials.Values.ToList());
List<Mesh> meshes = new List<Mesh>();
foreach (var group in result.Groups)
{
List<uint> meshIndices = new List<uint>();
foreach (var face in group.Faces)
{
Vector3 Q1 = new Vector3(
result.Vertices[face.Vertices[1].VertexIndex - 1].X - result.Vertices[face.Vertices[0].VertexIndex - 1].X,
result.Vertices[face.Vertices[1].VertexIndex - 1].Y - result.Vertices[face.Vertices[0].VertexIndex - 1].Y,
result.Vertices[face.Vertices[1].VertexIndex - 1].Z - result.Vertices[face.Vertices[0].VertexIndex - 1].Z);
Vector3 Q2 = new Vector3(
result.Vertices[face.Vertices[2].VertexIndex - 1].X - result.Vertices[face.Vertices[0].VertexIndex - 1].X,
result.Vertices[face.Vertices[2].VertexIndex - 1].Y - result.Vertices[face.Vertices[0].VertexIndex - 1].Y,
result.Vertices[face.Vertices[2].VertexIndex - 1].Z - result.Vertices[face.Vertices[0].VertexIndex - 1].Z);
double s1 = result.Textures[face.Vertices[1].TextureIndex - 1].X - result.Textures[face.Vertices[0].TextureIndex - 1].X;
double t1 = result.Textures[face.Vertices[1].TextureIndex - 1].Y - result.Textures[face.Vertices[0].TextureIndex - 1].Y;
double s2 = result.Textures[face.Vertices[2].TextureIndex - 1].X - result.Textures[face.Vertices[0].TextureIndex - 1].X;
double t2 = result.Textures[face.Vertices[2].TextureIndex - 1].Y - result.Textures[face.Vertices[0].TextureIndex - 1].Y;
double coefficient = 1.0 / (s1 * t2 - s2 * t1);
Vector3 sDir = new Vector3(t2 * Q1.X - t1 * Q2.X, t2 * Q1.Y - t1 * Q2.Y, t2 * Q1.Z - t1 * Q2.Z) * coefficient;
Vector3 tDir = new Vector3(s1 * Q2.X - s2 * Q1.X, s1 * Q2.Y - s2 * Q1.Y, s1 * Q2.Z - s2 * Q1.Z) * coefficient;
for (int i = 0; i < face.Vertices.Count; i++)
{
MeshPosition vertex = result.Vertices[face.Vertices[i].VertexIndex - 1];
MeshNormal normal = result.Normals[face.Vertices[i].NormalIndex - 1];
MeshTexCoord texture = result.Textures[face.Vertices[i].TextureIndex - 1];
Vector3 tempNormal = new Vector3(normal.X, normal.Y, normal.Z);
Vector3 tempTangent = (sDir - tempNormal * Vector3.Dot(tempNormal, sDir)).Normalized;
double handedness = (Vector3.Dot(Vector3.Cross(tempNormal, sDir), tDir) < 0.0) ? -1.0 : 1.0;
MeshTangent tangent = new MeshTangent((float)tempTangent.X, (float)tempTangent.Y, (float)tempTangent.Z, (float)handedness);
meshIndices.Add((uint)meshVertices.Count);
meshVertices.Add(new MeshVertex(
vertex,
normal,
texture,
tangent));
}
if (face.Vertices.Count == 3)
{
}
else if (face.Vertices.Count == 4)
{
uint vertexPointer1 = meshIndices[meshIndices.Count - 4];
uint vertexPointer2 = meshIndices[meshIndices.Count - 2];
meshIndices.Insert(meshIndices.Count - 1, vertexPointer1);
meshIndices.Insert(meshIndices.Count - 1, vertexPointer2);
}
else
{
throw new Exception("Only supports triangles or quads");
}
}
Mesh currentMesh = new Mesh(meshIndices.ToArray());
ApplyMaterial(currentMesh, group.Material, textures);
meshes.Add(currentMesh);
}
return new Model(meshVertices.ToArray(), meshes.ToArray(), textures.Values.ToArray());
}
public MeshVertex(MeshPosition pos, MeshNormal norm, MeshTexCoord texcoord, MeshTangent tangent)
{
Position = pos;
Normal = norm;
TexCoord = texcoord;
Tangent = tangent;
}