I bought an oculus rift development kit a few months ago and have used it to play and develop. It is probably the most innovative device you will encounter for the next few years - definitely worth trying it out.
The first experience
I was reluctant to purchase an oculus initially as I had not tried it out and had no idea about the sensation of wearing one. I was convinced when I saw the video of an old lady wearing one and her reaction. The first demo I tried out was 'RiftCoaster' - the Unreal citadel demo with a roller coaster placed on top of the scene. The sensation was quite unreal - I really felt that I was about to drop down 20 meters off the side of a castle and I rocked around in my office chair in sync with the virtual coaster. I highly recommend playing this as a first demo.
How to develop with the Oculus
I have tried setting up a development environment in but I prefer to use languages that I have been using for years so I opted for develop on the web, using WebGL and a plug-in called 'npvr' to give me access to the output from the oculus/hydra. The drawbacks to using WebGL is that there are no really good libraries to develop with. They are either really lacking features that is needed to make a proper game or abstract away WebGL so much that it is a nightmare to gain back control of the rendering process.
Where to go for demos:
There are numerous websites that list VR demos. I use the websites below to download new demos:
https://developer.oculusvr.com/forums/ - the official Oculus VR forums - if you look in 'Oculus Showcase' and 'Works in Progress' you can usually find downloads of new demos.
http://www.riftenabled.com/ - an independent listings site listing tech demos and projects all Oculus related.
The best demos so far
So far I have tried out 150 demos for the Oculus but there are only a handful I that I would show to my friends, these are:
RiftCoaster - the fist I tried and still the best - for visuals and to best show off the oculus
Bungee -a simple demo of standing on the edge of a bridge and jumping. To get the best effect put your hand on someone's back and give a little push when you press the jump button for them.
Kraken - more of a on-rails experience, once you get out to sea, you start sinking and see all sorts of scary things.
Malfunction - a good use of avatar, baked lighting and animation. You start to feel like you live there.
OculusFerrari - drive a ferrari in first-person, the best demo you can find for the Razor Hydra.
Hydra Cover Shooter - although very awkward to set up, it makes best use of the position tracking and there is nothing like holding your Hydra like a lightsaber.
Most of the demos I have used suffer the same technical problems. Most are affects of using an engine that was not designed for VR. Here are the common issues:
Lack of anti-aliasing - the oculus is typically rendered using deferred rendering and so hardware based anti-aliasing is not available and most demos suffer because of this. A solution would be to use differed anti-aliasing techniques like FXAA or SMAA or just use multi-sampling.
Particles/bill boarding - bill boarding is the process of pointing an object into the camera vision such that it faces the camera from different views. As the Oculus requires stereo rendering, the particle cannot be oriented to in both eyes at the same time as the depth should be different - giving the stereo effect.
Skyboxes - sometimes they are rendered incorrectly and it almost hurts looking at them. They should be rendered in screen space, per eye after oculus perspective correction, rendered as a cube map.
The Razor Hydra
There are a few demos out there that also work with the Hydra. However, I would not recommend purchasing a Hydra as my experiences with the device are mostly negative and there are very few good demos of using the Hydra.
Problems with the Oculus
If you look around the net you will see a list of common problems that everyone seems to have, including:
Low resolution - the current resolution is only 1280 x 800 (640 x 800 per eye) and it shows as things get blurry whilst looking around.
Chromatic aberration - this is the splitting of colours so when looking at corners you may see red or blue lines, where the pixel colour has split through the lens of the Oculus - this has been addressed in newer demos.
Screen-door effect - this is really evident when you are standing still in a scene, yours eyes start to focus on the screen and you notice that there are black lines running vertically and horizontally, splitting the pixels into an obvious grid. It is quite distracting.
Sickness - mostly due to the demo, resulting from too low frame rate, rocky movement or incorrect stereo rendering.
The new Oculus development kit addresses most of the common issues that people have about the device apart from one that I believe is a tech-killer.
The elephant in the room
What nobody, including Carmack and the guys at Oculus VR have not addressed is probably the most obvious and has been a burden on console gaming for years. What I am referring to is the lack of controls. It is very nice looking around a world but when it comes to interacting the current best solution is just to use a gamepad. I can't see the latest position tracing devices being used.
The perfect solution for me would be to use my hands.
If the guys at Oculus VR attached a front-facing depth camera to the front of the Oculus, you could pattern match your body and hands and place them within the scene, having the depth information at hand you would intersect the virtual environment and pressing buttons and hitting switches would be a matter of reaching up with your hand and hitting them.