New Gaming Technology Enables Smelling in VR

A collaboration between Stockholm University and Malmö University has led to the creation of a new technology that makes it possible to smell in a virtual reality (VR) environment. The new machine, called an olfactometer, can be printed on 3D printers.

The research was funded by the Marianna and Marcus Wallenberg Foundation and was published in the International Journal of Human — Computer Studies.

Jonas Olofsson is a professor of psychology and leader of the research project at Stockholm University.

“We hope that the new technical possibilities will lead to scents having a more important role in game development,” Olofsson says.

Developing a Scent Machine

Computer games have traditionally focused on what we can see, such as moving images on screens, rather than any other senses. But this is changing. The interdisciplinary research group developed a scent machine that can be controlled by a gaming computer. The participant moves in the game in a virtual wine cellar, picking up virtual wine glasses with different types of wine. The participant does this while guessing the aromas.

The scent machine is attached to the VR system’s controller. When the player lifts the glass, it releases a scent.

Simon Niedenthal is an interaction and game researcher at Malmö University.

“The possibility to move on from a passive to a more active sense of smell in the game world paves the way for the development of completely new smell-based game mechanics based on the players’ movements and judgements,” Niedenthal says.

Construction of the Olfactometer

The olfactometer has four different valves, with each one connected to a channel. The middle contains a fan that sucks air into a tube. The computer enables the player to control the four channels, which open to different degrees and provide different mixtures of scents. The scent blends mimic the complexities of real wine, and the game has different levels of difficulty based on the complexity.

“In the same way that a normal computer game becomes more difficult the better the player becomes; the scent game can also challenge players who already have a sensitive nose. This means that the scent machine can even be used to train wine tasters or perfumers,” Olofsson says.

The team has released all codes, blueprints, and instructions for the machine online, as well as the code for the virtual tasting games. The research group now hopes that scented computer games can expand their applications.

“For those who, for example, lost their sense of smell after COVID-19 or for other reasons, the new technology can mean an opportunity to regain their sense of smell with the help of game-based training,” Olofsson says.

“I hope that the fact that drawings and code are openly available as “open source” will lead to an opportunity for game companies to start creating new, commercial products for scent training using the new technology,” he continues.

Simon Niedenhal says that the open source aspect of the technology helps promote accessibility, reproducibility, and comparison of results. It also helps establish a research and design community within game development.

“But it also means that the costs of the equipment are greatly reduced, which makes it available to more people. To us that is important,” Niedenthal says.

“We believe in open science, that research results should be made available to the public and that other researchers should be able to repeat our results. With the help of our research, others can build scent machines and explore new ways of using scents in games,” Olofsson adds.