private void ConvertFace(IWavefrontObj wavefrontObj, Face face, Mesh mesh)
{
var points = new List<Vector3>();
var verticesCount = wavefrontObj.Vertices.Count;
for (var i = 0; i < face.Count; i++)
{
var faceVertex = face[i];
var actualVertexIndex = 0;
if (faceVertex.VertexIndex > 0)
{
actualVertexIndex = faceVertex.VertexIndex - 1;
}
else if (faceVertex.VertexIndex < 0)
{
actualVertexIndex = verticesCount + faceVertex.VertexIndex;
}
else
{
throw new InvalidDataException("Obj model contains a vertex index of 0.");
}
var geoVertex = wavefrontObj.Vertices[actualVertexIndex];
var point = new Vector3(geoVertex.X, geoVertex.Y, geoVertex.Z);
points.Add(point);
}
var polygon = new Polygon(points);
mesh.Faces.Add(polygon);
}
private Mesh ConvertGroup(IWavefrontObj wavefrontObj, Group group)
{
var mesh = new Mesh();
foreach (var face in group.Faces)
{
ConvertFace(wavefrontObj, face, mesh);
mesh.Name = group.Name;
}
return mesh;
}