Okay first off for the bear minimum we need to see in a virtual world and move in a virtual world... For the seeing in a virtual world they are creating a bionic eye to repair vision in blind or partially blind patients and they do this by connecting something to the part of the brain that processes images, to a camera on a pair of glasses (this is over simplified explanation.) and than basically they see what the camera sees instead of connecting, to a camera, connect it to a computer and code it so they see through the "camera" that would be on the head of a player model and you can see in that virtual world.. Now to move in that virtual world we would need to connect our other parts of the brain for moving limbs to a computer and code it so when a signal is sent from your brain to move an arm it would move in that world. to not hook up directly to brains we could use the New BMI tech that D.A.R.P.A created to hook up our brain to a computer without surgery.. There was a study done where they hooked up monkeys brains to a computer and they were able to move an arm to touch a target on 2d screen.
What do you think?
Links to studies and information:
https://www.technologyreview.com/s/608844/blind-patients-to-test-bionic-eye-brain-implants/
https://www.theguardian.com/science/2013/feb/28/brains-rats-connected-share-information
https://www.newscientist.com/article/dn27869-animal-brains-connected-up-to-make-mind-melded-computer/