public Task <Mesh> GetMeshAsync(int meshIndex)
{
GltfLoader.Schema.Mesh mesh = gltf.Meshes[meshIndex];
Span <byte> indexBuffer = Span <byte> .Empty;
IndexBufferView?indexBufferView = null;
bool is32BitIndex = false;
if (mesh.Primitives[0].Indices.HasValue)
{
indexBuffer = GetIndexBuffer(mesh, out int stride);
is32BitIndex = stride == sizeof(int);
indexBufferView = new IndexBufferView(GraphicsResource.CreateBuffer(GraphicsDevice, indexBuffer, ResourceFlags.None), is32BitIndex);
}
VertexBufferView[] vertexBufferViews = GetVertexBufferViews(mesh, indexBuffer, is32BitIndex);
int materialIndex = 0;
if (mesh.Primitives[0].Material.HasValue)
{
materialIndex = mesh.Primitives[0].Material ?? throw new Exception();
}
Node node = gltf.Nodes.First(n => n.Mesh == meshIndex);
float[] matrix = node.Matrix;
Matrix4x4 worldMatrix = Matrix4x4.Transpose(new Matrix4x4(
matrix[0], matrix[1], matrix[2], matrix[3],
matrix[4], matrix[5], matrix[6], matrix[7],
matrix[8], matrix[9], matrix[10], matrix[11],
matrix[12], matrix[13], matrix[14], matrix[15]));
float[] s = node.Scale;
float[] r = node.Rotation;
float[] t = node.Translation;
Vector3 scale = new Vector3(s[0], s[1], s[2]);
Quaternion rotation = new Quaternion(r[0], r[1], r[2], r[3]);
Vector3 translation = new Vector3(t[0], t[1], t[2]);
worldMatrix *= Matrix4x4.CreateScale(scale)
* Matrix4x4.CreateFromQuaternion(rotation)
* Matrix4x4.CreateTranslation(translation);
MeshDraw meshDraw = new MeshDraw
{
IndexBufferView = indexBufferView,
VertexBufferViews = vertexBufferViews
};
return(Task.FromResult(new Mesh(meshDraw)
{
MaterialIndex = materialIndex, WorldMatrix = worldMatrix
}));
}
public Mesh(MeshDraw meshDraw)
{
MeshDraw = meshDraw;
}