'How can I actually combine or merge geometries in Three.js?

How can I take 2 separate buffer geometries, and simply merge/combine them into one BufferGeometry in three.js which can also carry over all of the skinned attributes, uvs, vertices, etc?

I've been trying to find a solution to this because the default tools in three.js seem not to work, or they scramble certain parts of the geometry.



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