YouTube via FeelReal. Click for original.

VR is all about immersion, and so far the experiences have mostly been focused on two senses—sight and sound (in that order). At some point, it's a safe bet that the sense of smell will enter the equation, and it could happen sooner rather than later.

Benji Li, a postdoctoral researcher with Stanford's Virtual Human Interaction Lab, spoke with Engadget on the topic. He noted that "sight and sound have been the staple of VR environments," while haptic feedback has added a sense of touch. But going forward, smell and taste could be next.

"The thing about VR is its ability to allow the user to feel he/she is there, a phenomenon we call presence," Li explained. "We see greater influence of VR when users report higher levels of presence."

Li and his research team at Nanyang Technological University in Singapore submitted a study for peer review that examines how VR can influence a person's eating habits. More specifically, the team found that adding scent and taste to the experience "has an effect on human satiation."

"What if one day we are able to show you in VR, a piece of steak, with the smell and scent that goes along with it, and you cut it up and feel its tenderness, and you enjoy every bite of it?," Li told Engadget. "But in real life, it's made of plant-based ingredients."

This already exists to some extent. It's called Vocktail, and it tricks the senses through the use of light, smell, and "virtualized" taste to make liquids in a glass, including tap water, taste like pretty much anything.

A quick Google search shows there are other efforts to bring the sense of smell into VR, too. One of those is add-on for VR headsets like the Oculus Rift called FeelReal (shown in the image above). It's up for preorder and comes with a set of seven cartridges each one offering a different smell, including ocean, jungle, fire, grass, powder, flowers, and metal.

We can't help but imagine what the implications could be for gaming, at least one day. There are several hurdles that stand in the way of bringing a sense of smell in mainstream VR experiences, but perhaps one day we'll be able to smell the gunpowder after shooting a weapon, or the smoke from a billowing fireplace.

Much of it will be gimmicky, and probably expensive, at least early on. Here's hoping that not every effort to bring a sense of smell to VR stinks.