// Taken from here: https://gist.github.com/phosphoer/93ca8dcbf925fc006e4e9f6b799c13b0
private static BlendTree CloneBlendTree(BlendTree newTree, BlendTree oldTree)
{
// Create a child tree in the destination parent, this seems to be the only way to correctly
// add a child tree as opposed to AddChild(motion)
BlendTree pastedTree = newTree is null ? new BlendTree() : newTree.CreateBlendTreeChild(newTree.maxThreshold);
pastedTree.name = oldTree.name;
pastedTree.blendType = oldTree.blendType;
pastedTree.blendParameter = oldTree.blendParameter;
pastedTree.blendParameterY = oldTree.blendParameterY;
pastedTree.minThreshold = oldTree.minThreshold;
pastedTree.maxThreshold = oldTree.maxThreshold;
pastedTree.useAutomaticThresholds = oldTree.useAutomaticThresholds;
// Recursively duplicate the tree structure
// Motions can be directly added as references while trees must be recursively to avoid accidental sharing
foreach (var child in oldTree.children)
{
if (child.motion is BlendTree tree)
{
var childTree = CloneBlendTree(pastedTree, tree);
// need to save the blend tree into the animator
childTree.hideFlags = HideFlags.HideInHierarchy;
AssetDatabase.AddObjectToAsset(childTree, _assetPath);
}
else
{
var children = pastedTree.children;
ArrayUtility.Add(ref children, child);
pastedTree.children = children;
}
}
return(pastedTree);
}