private int AddMaterial(Model gltf, string name, WaveFront.Material mtl)
{
var mat = new Material();
mat.Name = name;
mat.PbrMetallicRoughness = new PbrMetallicRoughness();
var matIndex = gltf.Materials.Count;
float metallicFactor = 0.0f;
float?roughnessFactor = null;
// convertTraditionalToMetallicRoughness
float[] specular = null;
var specularShininess = mtl.SpecularExponent;
if (mtl.Specular != null)
{
specular = mtl.Specular.ToRGB();
metallicFactor = specular[0];
// if from blinn-phong model
var specularIntensity = Luminance(specular);
roughnessFactor = (mtl.SpecularExponent ?? 0.0f) / 1000;
roughnessFactor = 1.0f - roughnessFactor;
roughnessFactor = Clamp(roughnessFactor ?? 1.0f, 0.0f, 1.0f);
metallicFactor = 0.0f;
specular = new[] { metallicFactor, metallicFactor, metallicFactor, 1.0f };
specularShininess = roughnessFactor;
}
var emissiveTexture = mtl.EmissiveMap;
var normalTexture = mtl.BumpMap;
var occlusionTexture = mtl.AmbientMap;
var baseColorTexture = mtl.DiffuseMap;
var alphaTexture = mtl.DissolveMap;
var metallicTexture = mtl.SpecularMap;
var roughnessTexture = String.Empty;
//var metallicRoughnessTexture = createMetallicRoughnessTexture(
//var diffuseAlphaTexture
var emissiveFactor = mtl.Emissive?.ToRGB();
var baseColorFactor = mtl.Diffuse?.ToRGB()?.ToList() ?? new List <float> {
0.315f, 0.315f, 0.315f
};
if (IsValidTexture(emissiveTexture))
{
var tIndex = ResolveTexture(gltf, emissiveTexture);
if (tIndex != -1)
{
emissiveFactor = new float[] { 1.0f, 1.0f, 1.0f };
mat.EmissiveTexture = new TextureInfo
{
Index = tIndex
};
}
}
if (IsValidTexture(baseColorTexture))
{
var tIndex = ResolveTexture(gltf, baseColorTexture);
if (tIndex != -1)
{
baseColorFactor = new List <float> {
1.0f, 1.0f, 1.0f
};
mat.PbrMetallicRoughness.BaseColorTexture = new TextureInfo
{
Index = tIndex
};
}
}
if (IsValidTexture(metallicTexture))
{
metallicFactor = 1.0f;
var tIndex = ResolveTexture(gltf, metallicTexture);
mat.PbrMetallicRoughness.MetallicRoughnessTexture = new TextureInfo
{
Index = tIndex
};
}
if (IsValidTexture(roughnessTexture))
{
roughnessFactor = 1.0f;
}
if (IsValidTexture(normalTexture))
{
var tIndex = ResolveTexture(gltf, normalTexture);
if (tIndex != -1)
{
mat.NormalTexture = new NormalTexture
{
Index = tIndex,
Scale = 1
};
}
}
if (IsValidTexture(occlusionTexture))
{
var tIndex = ResolveTexture(gltf, occlusionTexture);
if (tIndex != -1)
{
mat.OcclusionTexture = new OcclusionTexture
{
Index = tIndex
};
}
}
baseColorFactor.Add(1.0f);
bool transparent;
if (IsValidTexture(alphaTexture))
{
transparent = true;
}
else
{
var alpha = mtl.Dissolve ?? 1.0f;
baseColorFactor[3] = alpha;
transparent = alpha < 1.0;
}
mat.DoubleSided = transparent;
mat.AlphaMode = new CheckedValue <AlphaMode, string>(transparent ? AlphaMode.BLEND : AlphaMode.OPAQUE);
mat.PbrMetallicRoughness.BaseColorFactor = baseColorFactor.ToArray();
mat.PbrMetallicRoughness.MetallicFactor = metallicFactor;
mat.PbrMetallicRoughness.RoughnessFactor = roughnessFactor;
mat.EmissiveFactor = emissiveFactor;
gltf.Materials.Add(mat);
return(matIndex);
}
/// <summary>
/// run converter
/// </summary>
/// <returns></returns>
public Model Run()
{
var model = new Model {
Asset = new Asset()
};
// parse obj files
var objModel = ObjParser.Parse(_objFile);
var mtlModels = new List <MtlModel>();
foreach (var mtl in objModel.MaterialLibaries)
{
var mtlM = MtlParser.Parse(Path.Combine(_objFolder, mtl));
mtlModels.Add(mtlM);
foreach (var m in mtlM.Materials)
{
var matName = m.Key;
var mm = m.Value;
var matIndex = AddMaterial(model, matName, mm);
_matDict.Add(matName, matIndex);
}
}
if (_matDict.Count == 0)
{
// add default material
var mat = new Material();
mat.Name = "default";
mat.PbrMetallicRoughness = new PbrMetallicRoughness();
mat.DoubleSided = true;
mat.PbrMetallicRoughness.BaseColorFactor = new float[] { 0.3f, 0.3f, 0.3f, 1.0f };
model.Materials.Add(mat);
_matDict.Add("default", 0);
}
AddNodes(model, objModel);
if (_options.GLB)
{
model.BinBuffers = new List <byte>();
if (_buffers.ImageBuffers.Count > 0)
{
model.BinBuffers.AddRange(_buffers.ImageBuffers.SelectMany(c => c));
}
model.BinBuffers.AddRange(_buffers.Positions.SelectMany(c => c));
if (_buffers.Normals.Count > 0)
{
model.BinBuffers.AddRange(_buffers.Normals.SelectMany(c => c));
}
if (_buffers.Uvs.Count > 0)
{
model.BinBuffers.AddRange(_buffers.Uvs.SelectMany(c => c));
}
model.BinBuffers.AddRange(_buffers.Indices.SelectMany(c => c));
}
if (model.Images.Count > 0)
{
model.Samplers.Add(new Sampler
{
MagFilter = new CheckedValue <MagFilter, int>(MagFilter.Linear),
MinFilter = new CheckedValue <MinFilter, int>(MinFilter.NearestMipmapLinear),
WrapS = new CheckedValue <WrappingMode, int>(WrappingMode.Repeat),
WrapT = new CheckedValue <WrappingMode, int>(WrappingMode.Repeat)
});
}
var doc = Document.Create();
doc.WriteModel(model, _gltfFile);
return(model);
}