The proliferation of solutions for 3D capture, have arrived with proprietary solutions, which force the final users to use some brands exclusively to prevent incompatibility issues (as the providers of that technology say). The 20/20 3D Media Spatial Sound and Vision research project, funded by the European Union, has been developed in parallel with the nowadays 3D renaissance, and by facing this kind of challenges while building the technology for the project, presents an initiative for standardization of metadata for 3D, named M3DI (Initiative on 3D Metadata), and that is offered as an input for future standardization activities. This initiative has already raised the interest of important players in the different stages of the incipient 3D industry.