VCGLib is fully owned by CNR, and all the VCGLib contributors that do not work at the VCLab of CNR must first sign the contributor license agreement that you can find at the following link: https://github.com/cnr-isti-vclab/vcglib/blob/devel/docs/ContributorLicenseAgreement.pdf
If you will sign the CLA, then we will be able to merge your pull request after reviewing it.