Torin Hopkins, PhD

AI & Music · Extended Reality

HoloJam

Exploring jamming with AI-driven hologram drummers.

Read the paper (PDF)DOI

HoloJam is a holographic jam space. Using the Pepper’s ghost illusion, animated drummers and bandmates appear as holograms that players can see without any headset, giving an unrestricted view of AI-driven virtual musicians.

How it works

A transparent acrylic board angled at 45° reflects a television image to create holograms. The installation runs on a single laptop. Avatars animated in Unity (models and animations from Mixamo, driven by a reactive rig) play drums, bass, guitar, and keys in response to the music, and players join on a MIDI drum pad.

HoloJam served as the no-field-of-view-limit condition in our studies of AR glasses, where it gave the highest co-presence, the fastest gesture recognition, and the greatest enjoyment.

Public demos

Beyond the research studies, HoloJam was exhibited as a public demo at ATLAS Institute expos at CU Boulder in 2022 and 2023. The papers that came out of the project were published from 2023 to 2025. Visitors stepped up to the drum pad and jammed with the holographic bandmates, no headset required.

Video

HoloJam video

Gallery

HoloJam (right) compared with AR glasses with and without Mini Musicians.
HoloJam (right) compared with AR glasses with and without Mini Musicians.
Avatar bandmates: bassist, guitarist, and keyboard player.
Avatar bandmates: bassist, guitarist, and keyboard player.

Publications

  1. Effects of Limited Field of View on Musical Collaboration Experience with Avatars in Extended Reality

    Suibi Che-Chuan Weng, Torin Hopkins, Shih-Yu Ma, Amy Banić, and Ellen Yi-Luen Do

    IEEE International Symposium on the Internet of Sounds (IS2), L'Aquila, Italy, pp. 1–11, 2025.

    AbstractPDFDOI

  2. Investigating the Effects of Limited Field of View on Jamming Experience in Extended Reality

    Suibi Che-Chuan Weng, Torin Hopkins, Shih-Yu Ma, Chad Tobin, Amy Banić, and Ellen Yi-Luen Do

    IEEE International Symposium on Mixed and Augmented Reality Adjunct (ISMAR-Adjunct), pp. 493–495, 2023.

    DOI

  3. How Field of View Affects Awareness of an Avatar During a Musical Task in Augmented Reality

    Suibi Che-Chuan Weng, Torin Hopkins, Rishi Vanukuru, Chad Tobin, Amy Banić, Daniel Leithinger, and Ellen Yi-Luen Do

    IEEE Conference on Virtual Reality and 3D User Interfaces (IEEE VR), Poster Session, pp. 633–634, 2023.

    AbstractPDFDOI