The result of normalising the bone vector wasn't checked, so it resulted in a zero-length vector being multiplied with the desired length. Choosing an arbitrary vector prevents the bone being 'stuck' at zero length. Thanks @mano-wii for the patch.
The result of normalising the bone vector wasn't checked, so it resulted in a zero-length vector being multiplied with the desired length. Choosing an arbitrary vector prevents the bone being 'stuck' at zero length. Thanks @mano-wii for the patch.