You will soon be able to pre-order a multisensory mask on Kickstarter. It will be strapped under the VR headset and should be able to spray 255 different smells around the user's nose in order to underline the environment in which one virtually dives olfactorily. Heat, wind draft, water vapour and vibrations are also generated by small gadgets in the mask.
Since the mask can only hold one cartridge with nine of the 255 aroma capsules, you have to decide beforehand for a quite modest set of smells depending on the film or game. The manufacturer offers special scent tracks to 360° films, it should also be own "composed" and others can be made available. For game developers who want to support the system, there will be an SDK.
Similar efforts to accompany the audiovisual happenings in the (home) cinema with actual scent and feeling sensations and thus to offer a more stirring experience have been made over the years 
always again -- Smell-o-vision sends its greetings. They all remained a short gimmick. At least some technical challenges should not occur here thanks to the mask. Also with the smell synthesizing there are to be announced surely progresses, at least since the sixties. When The Verge was able to try out the Feelreal mask a few years ago, it didn't seem to work very subtly; maybe an early prototype, and now the olfactory VR is finally making a breakthrough? 2019 will be truly exciting...
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