Virtual, augmented and mixed reality : design and interaction : 12th International Conference, VAMR 2020, held as part of the 22nd HCI International Conference, HCII 2020, Copenhagen, Denmark, July 19-24, 2020, Proceedings.: design and interaction : 12th International Conference, VAMR 2020, held as part of the 22nd HCI International Conference, HCII 2020, Copenhagen, Denmark, July 19-24, 2020, Proceedings. Part I (2020)