clone method
Returns a deep copy of this instance, preserving op if present.
Implementation
@override
ModelD clone() => .new(
op: op,
transform: transform.clone(),
meshes: meshes.map((x) => x.clone()).toList(),
materials: materials.map((x) => x.clone()).toList(),
meshMaterial: .from(meshMaterial),
currentPose: currentPose.map((x) => x.clone()).toList(),
boneMatrices: boneMatrices.map((x) => x.clone()).toList(),
);