Researchers from The University of Osaka have demonstrated for the first time that images projected using a shadowless projection mapping system can be perceived by observers as changes in color and texture of physical objects themselves, rather than as overlaid imagery

Osaka, Japan – Projection mapping is widely known as a lighting technique that overlays images onto buildings or objects to create visual effects. In fields such as extended reality (XR) and vision science, however, researchers have suggested that projection could go beyond simple overlays, potentially allowing the color, pattern, or even the perceived material properties of an object to appear as though they have physically changed.

In practice, this effect is difficult to achieve. Most projection mapping results are perceived not as changes in the object itself but as projected imagery layered on top of it. Visual cues such as shadows caused by a user’s body or directional lighting often reveal that the appearance is created by projection.

A research team led by Professor Daisuke Iwai of The University of Osaka Graduate School of Engineering Science, including master’s student Takahiro Okamoto and doctoral student Masaki Takeuchi, in collaboration with Associate Professor Masataka Sawayama of Hokkaido University, investigated how eliminating these cues might change human perception.

The researchers focused on a key difference between projected imagery and the physical appearance of real objects. Projected images can easily be blocked by a user’s body, creating shadows, whereas the color and texture of real objects do not disappear when illumination from one direction is obstructed.

In the future, the researchers envision that this system will be valuable for applications beyond entertainment, such as industrial design support, remote collaboration, and information presentation in medical environments.

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This research is to be presented as an oral presentation at the IEEE Conference on Virtual Reality and 3D User Interfaces, and it received Best Paper Award.

The article, “Shadowless Projection Mapping for Tabletop Workspaces with Synthetic Aperture Projector,” is to be published in IEEE Transactions on Visualization and Computer Graphics at DOI: https://doi.org/10.48550/arXiv.2603.11551