private static Gltf.Accessor getAccessor(Gltf.Gltf gltfModel, Gltf.Mesh gltfMesh, string key)
{
if (gltfMesh.Primitives[0].Attributes.TryGetValue(key, out var index))
{
return(gltfModel.Accessors[index]);
}
return(null);
}
public static ushort[] readIndices(string rootPath, Gltf.Gltf model, Gltf.Mesh mesh)
{
var accessor = model.Accessors[(int)mesh.Primitives[0].Indices];
var buffer = readBuffer(rootPath, model, accessor);
var indexArray = new ushort[accessor.Count];
System.Buffer.BlockCopy(buffer, 0, indexArray, 0, buffer.Length);
return(indexArray);
}
private static byte[] readBuffer(string rootPath, Gltf.Gltf model, Gltf.Accessor accessor)
{
var bufferView = model.BufferViews[(int)accessor.BufferView];
var buffer = model.Buffers[bufferView.Buffer];
using (var fs = new FileStream(Path.Combine(rootPath, buffer.Uri), FileMode.Open))
using (var reader = new BinaryReader(fs))
{
var byteArray = new byte[bufferView.ByteLength];
reader.BaseStream.Seek(bufferView.ByteOffset, SeekOrigin.Begin);
return(reader.ReadBytes(bufferView.ByteLength));
}
}
public Mesh(string rootPath, Gltf.Gltf model, Gltf.Mesh mesh)
{
var vertices = BufferReader.readVec3(rootPath, model, mesh, "POSITION");
var normals = BufferReader.readVec3(rootPath, model, mesh, "NORMAL");
var tangents = BufferReader.readVec4(rootPath, model, mesh, "TANGENT");
var texCoords = BufferReader.readVec2(rootPath, model, mesh, "TEXCOORD_0");
var indices = BufferReader.readIndices(rootPath, model, mesh);
IndexCount = indices.Length;
Material = new Material(rootPath, model, mesh);
VaoId = GL.GenVertexArray();
GL.BindVertexArray(VaoId);
VertexBuffer = GL.GenBuffer();
GL.BindBuffer(BufferTarget.ArrayBuffer, VertexBuffer);
GL.BufferData <Vector3>(BufferTarget.ArrayBuffer, vertices.Length * Vector3.SizeInBytes, vertices, BufferUsageHint.StaticDraw);
GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, Vector3.SizeInBytes, 0);
TexCoordBuffer = GL.GenBuffer();
GL.BindBuffer(BufferTarget.ArrayBuffer, TexCoordBuffer);
GL.BufferData <Vector2>(BufferTarget.ArrayBuffer, texCoords.Length * Vector2.SizeInBytes, texCoords, BufferUsageHint.StaticDraw);
GL.VertexAttribPointer(1, 2, VertexAttribPointerType.Float, false, Vector2.SizeInBytes, 0);
if (normals.Length > 0)
{
NormalBuffer = GL.GenBuffer();
GL.BindBuffer(BufferTarget.ArrayBuffer, NormalBuffer);
GL.BufferData <Vector3>(BufferTarget.ArrayBuffer, normals.Length * Vector3.SizeInBytes, normals, BufferUsageHint.StaticDraw);
GL.VertexAttribPointer(2, 3, VertexAttribPointerType.Float, false, Vector3.SizeInBytes, 0);
}
if (tangents.Length > 0)
{
TangentBuffer = GL.GenBuffer();
GL.BindBuffer(BufferTarget.ArrayBuffer, TangentBuffer);
GL.BufferData <Vector4>(BufferTarget.ArrayBuffer, tangents.Length * Vector4.SizeInBytes, tangents, BufferUsageHint.StaticDraw);
GL.VertexAttribPointer(3, 4, VertexAttribPointerType.Float, false, Vector4.SizeInBytes, 0);
}
IndexBuffer = GL.GenBuffer();
GL.BindBuffer(BufferTarget.ElementArrayBuffer, IndexBuffer);
GL.BufferData <ushort>(BufferTarget.ElementArrayBuffer, IndexCount * sizeof(ushort), indices, BufferUsageHint.StaticDraw);
GL.BindVertexArray(0);
}
public static Vector2[] readVec2(string rootPath, Gltf.Gltf model, Gltf.Mesh mesh, string key)
{
var result = new List <Vector2>();
var accessor = getAccessor(model, mesh, key);
if (accessor == null)
{
return new Vector2[] { }
}
;
var buffer = readBuffer(rootPath, model, accessor);
var floatArray = new float[accessor.Count * 2];
System.Buffer.BlockCopy(buffer, 0, floatArray, 0, buffer.Length);
for (var i = 0; i < accessor.Count * 2; i += 2)
{
result.Add(new Vector2(floatArray[i], floatArray[i + 1]));
}
return(result.ToArray());
}
public Material(string rootPath, Gltf.Gltf model, Gltf.Mesh mesh)
{
var materialId = mesh.Primitives[0].Material;
if (materialId == null)
{
throw new Exception("Mesh does not have a material!");
}
var material = model.Materials[(int)materialId];
var baseColorTextureIndex = material.PbrMetallicRoughness.BaseColorTexture.Index;
var baseColorTextureName = model.Images[(int)model.Textures[baseColorTextureIndex].Source].Uri;
BaseColorTexture = new Texture();
BaseColorTexture.LoadTexture(Path.Combine(rootPath, baseColorTextureName), true);
if (material.NormalTexture != null)
{
var normalTextureIndex = material.NormalTexture.Index;
var normalTextureName = model.Images[(int)model.Textures[normalTextureIndex].Source].Uri;
NormalTexture = new Texture();
NormalTexture.LoadTexture(Path.Combine(rootPath, normalTextureName), true);
}
if (material.PbrMetallicRoughness.MetallicRoughnessTexture != null)
{
var roughnessTextureIndex = material.NormalTexture.Index;
var roughnessTextureName = model.Images[(int)model.Textures[roughnessTextureIndex].Source].Uri;
RoughnessTexture = new Texture();
RoughnessTexture.LoadTexture(Path.Combine(rootPath, roughnessTextureName), true);
}
DoubleSided = material.DoubleSided;
Roughness = material.PbrMetallicRoughness.RoughnessFactor;
}
