GLTFMesh represents a GLTF mesh. GLTFMesh handles 3D mesh data imported from GLTF files. It includes properties for blend channels, blend weights, instance materials, and the mesh itself. $DOCS_URL/tutorials/io/runtime_file_loading_and_saving.html Gets additional arbitrary data in this [GLTFMesh] instance. This can be used to keep per-node state data in [GLTFDocumentExtension] classes, which is important because they are stateless. The argument should be the [GLTFDocumentExtension] name (does not have to match the extension name in the GLTF file), and the return value can be anything you set. If nothing was set, the return value is null. Sets additional arbitrary data in this [GLTFMesh] instance. This can be used to keep per-node state data in [GLTFDocumentExtension] classes, which is important because they are stateless. The first argument should be the [GLTFDocumentExtension] name (does not have to match the extension name in the GLTF file), and the second argument can be anything you want. An array of floats representing the blend weights of the mesh. An array of Material objects representing the materials used in the mesh. The [ImporterMesh] object representing the mesh itself. The original name of the mesh.