Panoramic VR environments versus Interactive VR environments
For quite a few years now, there have been two disparate industries, both claiming to be true VR.
One is the panoramic VR camp, which includes Quicktime VR as one of the most popular, and numerous other formats, including a couple that are shockwave based. VR Panoramas are basically a collection of graphics files; overlapped and stitched together to form a single flat, wrap around image.
Panoramic software then takes the image and wraps it onto the inside surface of a virtual cube or cylinder, then joins the two ends (or sixteen ends in the case of a cube) together seamlessly to form a panoramic image.
The viewer is situated in the empty space in the middle of the image, and can look left, right, up and down at the view around them, as though they were actually rooted to that spot.
Sometimes panoramic VR allows tours. A tour can be within the VR by means of hotspots. Hotspots are areas of the panoramic image file that have a function assigned to them so when you click or roll over with a mouse the action occurs - basically the same as an image map.
Alternatively an exterior map in another application such as a web page will allow clicking in different rooms of a building to view them.
Whichever the method used, a panoramic VR will not move from one room to the next. You will not see the door open and yourself step through. Instead, one panoramic still image will fade out, and your view will be replaced by the second. Navigation is thus nothing more than a series of still jumps, like looking through a collection of photographs.
The advantage a panoramic VR has is you tend to feel more inside the photograph. VR panoramic photos are very good at capturing the find detail of a photograph - every lighting condition, nick-nak on the shelves, and shadow is captured in fine detail. Thus, the ability to show a room as one immersive image is for some companies more suitable than normal photographs.
Panoramic VR basically allows exploration through 360° (sometimes 360° x 360°) of a given location or environment. For example, a pub might use panoramic VR to show off a virtual tour of their bar, eating facilities, party hall, conference suite, beer garden and views. An estate agent might desire to show off every room in a property, plus the location from every angle, and in fine detail.
The main advantage of course, is, as with all VR, you are viewing from the comfort of your office or home.
Interactive VR on the other hand, has many camps. MUDs, MUSHes, VRML, Renderware, Second Life, CAVEs, CUBEs, the list goes on forever. What all variants have in common however, is that the user can participate with the virtual scene - they can move about and the scene will dynamically update. They can pick things up and move them around. They can change things.
To make this comparison fair, we will only deal with the more modern interactive VRs - the graphical ones. These environments are built, painstakingly from the ground up, as a series of 3D models. For example, to form a kitchen, the oven would be one model, the oven door another, the hot plates separate, cupboards and doors, china, food, glasses, bottles, lights, sink, taps, doors, windows, wallpaper
Everything put together to form a virtual representation of a physical space, or a non-physical space such as a mathematical space, or design prototype.
Movement through interactive VR landscapes is natural - either via arrow keys, joystick, or even natural walking. The display updates as you move through it, exactly as it would if you were physically in the room. You can see objects from different angles as you walk round them, and there is no limit to the number of angles you can view from.
Any door can be opened, and you will see it opening on its hinges, plates picked up, examined, thrown on the floor, or put back somewhere else. In many it would even be possible to put toast in the toaster.
Interactive VR basically allows exploration through 360° x 360° x free movement in a given location or environment. Interactive VR really comes into its own when prototyping, or showing off a building not constructed yet, for show homes, for education, for any purpose where you really should be able to interact with the environment.
The main disadvantage is it cannot yet show an environment photo-perfectly, nor show it as it is, physically. The main advantage is, as with all VR, you are interacting from the comfort of your office or home.