I really enjoy the idea of virtual reality, and I wonder what is the most realistic system we could devise at the moment with our current technology. I'd prefer technology that is commonplace and feasible for use in a normal environment.
Now obviously for vision, you'd use goggles to get the most immersive effect.
Earphones allow you to hear.
A quality microphone capable of supporting a high sampling rate could allow for voice input.
Smell and taste I can't see being economically feasible or technologically possible with current technology. A possible system though might have reservoirs that hold scent and flavor chemicals, and a basic processing center like maybe a mixer or heater, and a ventilation and feed system that could transport the scents and flavors. It would probably have a very limited number of scents and flavors and would probably be expensive or difficult to replace the chemicals.
As for basic touch sensations, such as heat or cold, pain, and pressure, a suit might be devised that had heating/cooling coils, an air pressure system (instead of heating and cooling coils, it might be conducive to have an air heating or cooling system, and electrodes on it for electric jolts giving pain. Of course, strong measures would have to be taken to ensure that the suit would remain in the control of the user at all times and that safe bounds were placed on all functions as well as fail safes. This would probably be one of the more uncomfortable systems to use. It would also be one of the greater energy consumers and have a high price as well.
Motion for the upper body is fairly easy to solve. The thing I dislike about most virtual realities (games included) is that your avatar/character's head is stuck in a brace. Meaning your eyesight is facing the same way as your body. In real life, your head is on a swivel with the ability to look left, right, up, and down, and anywhere in between. This could be remedied if the virtual reality was written to support it. And it could be implemented in the vision goggles/headset. Another interesting feature might be having a vest and belt to indicate where your head was in relation to your torso. This would allow a virtual reality to recognize if a person bent for instance.
Hand motion is a part of that too. There have been game gloves to detect motion. Again, elbow-pads and shoulder-pads or some other device would allow more information into the virtual world about the way your arms are positioned and bent.
The most difficult part of motion in VR is the lower body. Say you wanted to walk or run. You can't traditionally walk or run because eventually you'll run out of space or get too far away from the computer. You could get on a treadmill or some other device, but how would it know how to match your movement speed? How would it allow for range of movement? I think the best system for lower body movement is a full body suspension system. Not only would it allow you to walk in just about any way you could move your legs, it could also allow for 360 degrees of movement in all axes, and it could allow for unusual movements such as swimming. Of course, this would be the most difficult to design physically speaking. Most people aren't physically fit enough to use normal suspension. It would have to not only encompass everything mentioned above, but it would also have to be as comfortable for the user as possible. Preferably as comfortable as a person is when he or she is normally standing or walking. If it were designed well enough, it might even reduce impact on joints. As a plus, it might also be possible to work out some sort of resistance system that could simulate forces. (Lifting weight, pushing, etc.) The problems with this is it would be another expensive system, it would be difficult to create an environment for it, (I can't see it fitting well in normal rooms) , and it would still be uncomfortable for people to use.
One final system I saw was the OCZ NIA Brain-Computer Interface. It is a headband that can detect upper facial muscle movements (including eye movements) and brain waves. There might be several applications for this, such as emotion or thought detection, changing what you see based upon eye movements, (for instance, if you squint maybe part of the screen you saw would sharpen while the edges blur or something), and in fantastical VRs abilities such as telekinesis, etc.
One day I believe that we will be able to experience virtual reality directly via our nervous system without the need to receive or transmit input through external peripherals. However, at the moment we must depend on these devices if we want a VR system. What are some devices and technologies that you can think of that might let us have VR now?