Message from the ISMAR 2021 Science and Technology Journal Program Chairs and TVCG Guest Editors

In this special issue of IEEE Transactions on Visualization and Computer Graphics (TVCG) , we are pleased to present the journal papers from the 20th IEEE International Symposium on Mixed and Augmented Reality (ISMAR 2021), which will be held as a virtual conference between October 4 and 8, 2021. ISMAR continues the over twenty year long tradition of IWAR, ISMR, and ISAR, and is the premier conference for Mixed and Augmented Reality in the world.