There are some problems with 3D nature of objects created by mankind. It could be surprising, but just a few people, who are working in some special jobs, are used to think in 3 dimensions, most people can not orient themselves in such environment except they are guided. If you ask anyone, what is the farest object they can see, they probably look to the Earth's horizon and say, that it is the building 5 kilometers far. Mostly they do not think about top direction, where they can see the Sun in distance about 30.000.000 times farer! That is our nature, we walk on the Earth, we are not used to fly. That means that if we build complete 3D model of the building (with all interiors), it would be nearly useless as the map, we must cut the building into separate 2D floors. Or there is another way of presentation, which is available few last years, when computers became able to replay animations in random order without slow seeking - it is possible to record movie, which shows the movement from one point, say the main entrance, to the other, for instance director's room.

You probably agree that this sentence is a bit hard to remember, especially when it is more than three times longer (this sometimes happens in one of the old buildings of our university). Man's memory much more remembers animation and some unique orientation points, especially when one can replay the animation many times simply. Also, orientation points can make one remember more information seen previously - the brain's memory works on principle of associations (and, of course, these unique objects are good input for this process).

Let us now derive some results form these ideas:

• The system must contain unique orientation objects - like flowers, noticeboards, lifts, stairs, doors, passages from one building to another etc.
• The system of navigation should contain at least descriptions of paths from these important points in the building to the place one is going to, if it is not capable of searching for the path from one to another point interactively.
• The system, should contain information about overall architecture of the building - for instance the user should learn quickly, that when he comes to the red lift, he is in the right corner of the building, and yellow lift is in the left.
• The information provided by the system must be very simply accesible, that means faster than asking the college. That is why most interactive solutions of this problem are useless - we are limited to interactive, computer-based solutions.
• The system should also contain more than a map. It is useless to have complete list of rooms described by the numbers, when one wants to search for the concrete office.
• The system should be simply updatable, that means server-based solution, perhaps in only very special cases, where system operator is able to configure replication of files, we can recommend distributed solution.
• The creation process of the design should be fast and inexpensive, otherwise none would make it. On the other hand the system should be quite complex and full of useful information.
• Common networks in the building of common companies or offices are too slow for realtime video solutions, also office computers are not graphic workstations, the solution must be small and not too CPU-intensive - at least for some next years.
• The solution should be designed by using industry-standard technologies with continuous development and support of new releases of operating systems. Also, client licenses should be free of charge.

There are few technologies we can use, but probably the simplest and completely inexpensive is to design common web site on the building intranet. Nearly everyone has access to WWW, that means he or she has installed browser. Downloading the plug-ins for extra capabilities is also simple, the plug-ins are mostly free.

There are following technologies available:

• Frames, that means more documents loaded in one window. The user has still access to main menus and the site is very simple to use.
• Java, JavaScript and dynamic HTML is very strong "weapon" in our hands. One can do unbelievable things with it, even more complex effects than in most special presentation programs. Currently it also means ability to render 3D graphics, move objects on the screen, sort database on the client's machine, play sound animation and using Java or ActiveX run complex business software. I have used Internet Explorer as a base for my friend painter Martin Zhouf's interactive gallery commercial presentation!
• We can use Apple QuickTime VR or other (for instance LivePicture) plug-ins to show spherical or cylindrical views of the scene.
• VRML2 is quite complex and powerful technology, it is our choice because of ability of scripting, fast development of the technology, very small data files and real-time (well, sometimes near-to-real-time) output rendered using client's CPU.

I decided to use combination of VRML2 and HTML extended by Java scripts in my systems. There exist very good authoring tools for each of these technologies and they are widely accepted as industry-standards. The rest of this paper is just a list of experiences I have learnt about these technologies and partially also a how-to guide.