public async Task <Texture> GetTextureAsync(int textureIndex, bool isSRgb = false)
{
int imageIndex = gltf.Textures[textureIndex].Source ?? throw new Exception();
GltfLoader.Schema.Image image = gltf.Images[imageIndex];
int bufferViewIndex = image.BufferView ?? throw new Exception();
BufferView bufferView = gltf.BufferViews[bufferViewIndex];
byte[] currentBuffer = buffers[bufferView.Buffer];
MemoryStream stream = new MemoryStream(currentBuffer, bufferView.ByteOffset, bufferView.ByteLength);
Texture texture = await Texture.LoadAsync(GraphicsDevice, stream, isSRgb);
return(texture);
}
public async Task <MaterialAttributes> GetMaterialAttributesAsync(int materialIndex)
{
Material material = gltf.Materials[materialIndex];
int?diffuseTextureIndex = material.PbrMetallicRoughness.BaseColorTexture?.Index;
int?metallicRoughnessTextureIndex = material.PbrMetallicRoughness.MetallicRoughnessTexture?.Index;
int?normalTextureIndex = material.NormalTexture?.Index;
if (!diffuseTextureIndex.HasValue)
{
if (material.Extensions.TryGetValue("KHR_materials_pbrSpecularGlossiness", out object value) && value is JsonElement element)
{
JsonProperty diffuseTextureProperty = element.EnumerateObject().FirstOrDefault(p => p.Name == "diffuseTexture");
if (!EqualityComparer <JsonProperty> .Default.Equals(diffuseTextureProperty, default))
{
diffuseTextureIndex = diffuseTextureProperty.Value.EnumerateObject().First(p => p.Name == "index").Value.GetInt32();
}
}
}
int?specularGlossinessTextureIndex = null;
if (!metallicRoughnessTextureIndex.HasValue)
{
if (material.Extensions.TryGetValue("KHR_materials_pbrSpecularGlossiness", out object value) && value is JsonElement element)
{
JsonProperty specularGlossinessTextureProperty = element.EnumerateObject().FirstOrDefault(p => p.Name == "specularGlossinessTexture");
if (!EqualityComparer <JsonProperty> .Default.Equals(specularGlossinessTextureProperty, default))
{
specularGlossinessTextureIndex = specularGlossinessTextureProperty.Value.EnumerateObject().First(p => p.Name == "index").Value.GetInt32();
}
}
}
MaterialAttributes materialAttributes = new MaterialAttributes();
if (diffuseTextureIndex.HasValue)
{
Texture diffuseTexture = await GetTextureAsync(diffuseTextureIndex.Value, true);
materialAttributes.Diffuse = new MaterialDiffuseMapFeature(new ComputeTextureColor(diffuseTexture));
}
else
{
float[] baseColor = material.PbrMetallicRoughness.BaseColorFactor;
Vector4 color = new Vector4(baseColor[0], baseColor[1], baseColor[2], baseColor[3]);
materialAttributes.Diffuse = new MaterialDiffuseMapFeature(new ComputeColor(color));
}
if (metallicRoughnessTextureIndex.HasValue)
{
Texture metallicRoughnessTexture = await GetTextureAsync(metallicRoughnessTextureIndex.Value);
materialAttributes.MicroSurface = new MaterialRoughnessMapFeature(new ComputeTextureScalar(metallicRoughnessTexture, ColorChannel.G));
materialAttributes.Specular = new MaterialMetalnessMapFeature(new ComputeTextureScalar(metallicRoughnessTexture, ColorChannel.B));
}
else if (specularGlossinessTextureIndex.HasValue)
{
Texture specularGlossinessTexture = await GetTextureAsync(specularGlossinessTextureIndex.Value);
materialAttributes.MicroSurface = new MaterialRoughnessMapFeature(new ComputeTextureScalar(specularGlossinessTexture, ColorChannel.A))
{
Invert = true
};
materialAttributes.Specular = new MaterialSpecularMapFeature(new ComputeTextureColor(specularGlossinessTexture));
}
else
{
float roughness = material.PbrMetallicRoughness.RoughnessFactor;
float metalness = material.PbrMetallicRoughness.MetallicFactor;
materialAttributes.MicroSurface = new MaterialRoughnessMapFeature(new ComputeScalar(roughness));
materialAttributes.Specular = new MaterialMetalnessMapFeature(new ComputeScalar(metalness));
}
if (normalTextureIndex.HasValue)
{
Texture normalTexture = await GetTextureAsync(normalTextureIndex.Value);
materialAttributes.Surface = new MaterialNormalMapFeature(new ComputeTextureColor(normalTexture));
}
return(materialAttributes);
}
public async Task <MaterialAttributes> GetMaterialAttributesAsync(int materialIndex)
{
Material material = gltf.Materials[materialIndex];
int?diffuseTextureIndex = material.PbrMetallicRoughness.BaseColorTexture?.Index;
int?metallicRoughnessTextureIndex = material.PbrMetallicRoughness.MetallicRoughnessTexture?.Index;
int?normalTextureIndex = material.NormalTexture?.Index;
if (!diffuseTextureIndex.HasValue)
{
if (material.Extensions?.FirstOrDefault().Value is Newtonsoft.Json.Linq.JObject jObject && jObject.TryGetValue("diffuseTexture", out Newtonsoft.Json.Linq.JToken token))
{
if (token.FirstOrDefault(t => (t as Newtonsoft.Json.Linq.JProperty)?.Name == "index") is Newtonsoft.Json.Linq.JProperty indexToken)
{
diffuseTextureIndex = (int)indexToken.Value;
}
}
}
int?specularGlossinessTextureIndex = null;
if (!metallicRoughnessTextureIndex.HasValue)
{
if (material.Extensions?.FirstOrDefault().Value is Newtonsoft.Json.Linq.JObject jObject && jObject.TryGetValue("specularGlossinessTexture", out Newtonsoft.Json.Linq.JToken token))
{
if (token.FirstOrDefault(t => (t as Newtonsoft.Json.Linq.JProperty)?.Name == "index") is Newtonsoft.Json.Linq.JProperty indexToken)
{
specularGlossinessTextureIndex = (int)indexToken.Value;
}
}
}
MaterialAttributes materialAttributes = new MaterialAttributes();
if (diffuseTextureIndex.HasValue)
{
Texture diffuseTexture = await GetTextureAsync(diffuseTextureIndex.Value);
materialAttributes.Diffuse = new MaterialDiffuseMapFeature(new ComputeTextureColor(diffuseTexture));
}
else
{
float[] baseColor = material.PbrMetallicRoughness.BaseColorFactor;
Vector4 color = new Vector4(baseColor[0], baseColor[1], baseColor[2], baseColor[3]);
materialAttributes.Diffuse = new MaterialDiffuseMapFeature(new ComputeColor(color));
}
if (metallicRoughnessTextureIndex.HasValue)
{
Texture metallicRoughnessTexture = await GetTextureAsync(metallicRoughnessTextureIndex.Value);
materialAttributes.MicroSurface = new MaterialRoughnessMapFeature(new ComputeTextureScalar(metallicRoughnessTexture, ColorChannel.G));
materialAttributes.Specular = new MaterialMetalnessMapFeature(new ComputeTextureScalar(metallicRoughnessTexture, ColorChannel.B));
}
else if (specularGlossinessTextureIndex.HasValue)
{
Texture specularGlossinessTexture = await GetTextureAsync(specularGlossinessTextureIndex.Value);
materialAttributes.MicroSurface = new MaterialRoughnessMapFeature(new ComputeTextureScalar(specularGlossinessTexture, ColorChannel.A))
{
Invert = true
};
materialAttributes.Specular = new MaterialSpecularMapFeature(new ComputeTextureColor(specularGlossinessTexture));
}
else
{
float roughness = material.PbrMetallicRoughness.RoughnessFactor;
float metalness = material.PbrMetallicRoughness.MetallicFactor;
materialAttributes.MicroSurface = new MaterialRoughnessMapFeature(new ComputeScalar(roughness));
materialAttributes.Specular = new MaterialMetalnessMapFeature(new ComputeScalar(metalness));
}
if (normalTextureIndex.HasValue)
{
Texture normalTexture = await GetTextureAsync(normalTextureIndex.Value);
materialAttributes.Surface = new MaterialNormalMapFeature(new ComputeTextureColor(normalTexture));
}
return(materialAttributes);
}
