Virtual reality How-to's

How to: setting up VRML browsers to take maximum advantage of your hardware equipment

Common: If your computer is equipped with a graphics card featuring 3d acceleration (most of todays graphics cards), you may get significant performance improvement, when browsing VRML scenes. The only prerequisity is a functional (lets say mostly functional) and properly installed display driver, which opens other graphical interfaces - renderers.

Both VRML plugins feature a default software renderer, which can be used either when no 3d hardware is available or to track bugs in graphics card drivers (belive me, there are many !). Also, both the plugins are capable of detecting additional available renderers (most common are DirectX and OpenGL). DirectX is more common and (usualy) the DirectX drivers contain less bugs than OpenGL. The one exception I've come accross are nVidia cards, where the OpenGL interface is stable and fast.

Windows 95/98/ME/2000/XP : Here you can take advatage of either DirectX or OpenGL depending on your graphics card drivers.

Windows NT: only OpenGL is available and is often software emulated or buggy.

Software renderers, that come in plugin's instalation, are available on all Windows platforms and do not require any specialized display drivers..

Blaxxun:

Blaxxun usualy finds the fastest renderer during instalation (usualy DirectX). But you can change it any time. Click with you right mouse button on an opened VRML scene to open Blaxxun's pop-up menu. Actualy the language may be different.

In the lower part of the pop-up menu, there are all available renderers. Here it is: OpenGL, Software renderer (High quality), DirectX (Hardware), again another Software renderer (Reference rasterizer) and Direct3D TL HAL, which is usualy the fastest. If you do not have all these, don't panic. Select from the ones you have and compare to others in terms of image quality, system stability, speed etc. Please note, that if you choose OpenGL here, you need to reload the scene (to make Blaxxun change the renderer) and OpenGL from this moment is your default renderer. Of course it can be easily changed to any other later.

When you find you favourite renderer, go to settings and make it permanent. Select your Direct 3D driver.

Cortona:

Setting Cortona VRML client is very similar. Again it features a pop-up menu, where choose "Preferences" and a tab called "Renderer". And choose your favourite renderer.

How to: downloading the scenes and offline viewing issues

A VRML scene can be downloaded to your computer and viewed offline. VRML file is "just" a file containing data (from the user's point of view) so it can be downloaded just like ZIP archives or pictures. All the links on these pages are direct, so clicking on a link with your right mouse button and choosing "Save target link as.." (or whatever it is called) is a good way to download a VRML scene file.

However ! Most of these scenes are composed of multiple VRML files. This is the reason why there are links to standalone models. Since I do not have enough web space, standalone zip archives containing whole scenes are not available.

So lets say, you want to download the screensaver scene. You have to download both files the scene is composed from : scrsaver.wrl and t77a.wrl. Save them into the SAME directory and open your local copy of scrsaver.wrl using your internet browser.

scene	composed from
screen saver	scrsaver.wrl, t77a.wrl
presentation hall	hall.wrl, t77a.wrl
large outdoor scene	too many files, mostly textures, use the other method for downloading

There exists another method. I'm sure you are using it but you don't know about it. Blaxxun plugin has a default option to download internet worlds to local harddisk. It is a kind of cache. Everytime you open a VRML scene on the internet, Blaxxun downloads automatically all the components of the scene (sometimes most of them :) ), displays the scene AND also saves all in its cache. The only problem is to find, where the cache is located on your harddisk and extract the proper files from it :). This also sometimes requires a bit more knowledge of VRML and scene composing.

I think Cortona does something similar, but don't use Cortona much.

How to: cut pictures

Even though either VRML plugins do not have the capability to cut pictures (or make screenshots), there is always one simple possibility, how to do it. Using the key PrintScreen it is possible to make screenshot of the whole desktop area including everything displayed (there are some exceptions, but these are not important now). The open your favourite image editor, create new picture and paste the screenshot into.

Any other how-to about virtual reality

mailto:drracer@seznam.cz . I'll do my best :)