public static Dictionary<string, Material> LoadFromFile(string filename)
{
var materials = new Dictionary<string, Material>();
try
{
string currentMaterial = "";
string path = Path.Combine("Assets", "Materials", filename);
using (StreamReader reader = new StreamReader(new FileStream(path, FileMode.Open, FileAccess.Read)))
{
string currentLine;
while (!reader.EndOfStream)
{
currentLine = reader.ReadLine();
if (!currentLine.StartsWith("newmtl"))
{
if (currentMaterial.StartsWith("newmtl"))
{
currentMaterial += currentLine + "\n";
}
}
else
{
if (currentMaterial.Length > 0)
{
Material newMaterial = new Material();
string newMaterialName = "";
newMaterial = LoadFromString(currentMaterial, out newMaterialName);
materials.Add(newMaterialName, newMaterial);
}
currentMaterial = currentLine + "\n";
}
}
}
if (currentMaterial.Count((char c) => c == '\n') > 0)
{
Material newMaterial = new Material();
string newMaterialName = "";
newMaterial = LoadFromString(currentMaterial, out newMaterialName, filename);
materials.Add(newMaterialName, newMaterial);
}
}
catch (FileNotFoundException e)
{
Console.WriteLine($"!!! ERROR: mtl file not found ({filename}) !!!");
}
catch (Exception e)
{
Console.WriteLine($"!!! ERROR: cannot load mtl ({filename}) !!!");
}
return materials;
}
public static Material LoadFromString(string material, out string name, string filename = null)
{
Material output = new Material();
name = "";
List<string> lines = material.Split('\n').ToList();
lines = lines.SkipWhile(s => !s.StartsWith("newmtl ")).ToList();
if (lines.Count != 0)
{
name = lines[0].Substring("newmtl ".Length);
}
lines = lines.Select((string s) => s.Trim()).ToList();
foreach (string l in lines)
{
if (l.Length < 3 || l.StartsWith("//") || l.StartsWith("#"))
{
continue;
}
// ambient color
if (l.StartsWith("Ka"))
{
output.AmbientColor = ParseColor(l, filename);
}
// diffuse color
if (l.StartsWith("Kd"))
{
output.DiffuseColor = ParseColor(l, filename);
}
// specular color
if (l.StartsWith("Ks"))
{
output.SpecularColor = ParseColor(l, filename);
}
// specular exponent
if (l.StartsWith("Ns"))
{
float exponent = 0.0f;
bool success = float.TryParse(l.Substring(3), out exponent);
output.SpecularExponent = exponent;
if (!success)
{
if (filename != null)
{
Console.WriteLine($"!!! ERROR: cannot parse specular exponent (line: {l}, file: {filename}) !!!");
}
else
{
Console.WriteLine($"!!! ERROR: cannot parse specular exponent (line: {l}, from string) !!!");
}
}
}
// diffuse map
if (l.StartsWith("map_Kd"))
{
// Check that file name is present
if (l.Length > "map_Kd".Length + 6)
{
output.DiffuseTexture = new Texture(l.Substring("map_Kd".Length + 1), TextureType.DIFFUSE);
}
}
// specular map
if (l.StartsWith("map_Ks"))
{
// Check that file name is present
if (l.Length > "map_Ks".Length + 6)
{
output.SpecularTexture = new Texture(l.Substring("map_Ks".Length + 1), TextureType.SPECULAR);
}
}
// normal map
if (l.StartsWith("map_normal"))
{
// Check that file name is present
if (l.Length > "map_normal".Length + 6)
{
output.NormalTexture = new Texture(l.Substring("map_normal".Length + 1), TextureType.NORMAL);
}
}
// opacity map
if (l.StartsWith("map_opacity"))
{
// Check that file name is present
if (l.Length > "map_opacity".Length + 6)
{
output.OpacityTexture = new Texture(l.Substring("map_opacity".Length + 1), TextureType.OPACITY);
}
}
}
return output;
}
