Making Matter

Help with Exploring these Pages

Index © M. Hewat 1998-2001 Help

  • The Size of WWW Browser Windows
    If your WWW window occupies the whole screen, reduce it now by clicking in the top right box. We will use a second WWW window to show the 3D objects, and this will be hidden if your main window is full screen.

  • Suitable WWW Browsers
    You can read these pages with any kind of computer using any WWW browser such as a recent version of Netscape or Internet Explorer. A faster download may be obtained from ZDNet

  • The 3D Structure Window
    Click here to display the 3D structure window. If this second window does not display a 3D structure, you must first download a 3D VRML viewer such as CosmoPlayer for Windows and Macintosh, or VRMLview for Windows, Linux, BeOS and SGI. This will allow you to see the structures in 3D, turn them around and explore inside them. A faster CosmoPlayer download may be obtained from ZDNet or from our own server for Win-95 or Macintosh. Although we recommend CosmoPlayer2.1.1 or VRMLview, you can find other VRML viewers at the VRML Repository. If you have a Silicon Graphics machine with a recent system, the best VRML-1 viewer is the built-in "ivview" application.

  • Installing Cosmo 2.1.1 under Windows-95/98/NT
    First uninstall any old versions of Cosmo and restart the machine. Then when installing Cosmo, make sure you select use with "un-supported" browsers. Recent verions of Netscape and MSIE will not be recognised by the Cosmo installer, but of course work perfectly well with Cosmo. If CosmoPlayer does not work under Netscape, copy the npcosmop211.* files manually to the plugins folder and re-start Netscape. Note that older versions of MSIE will only display gzipped VRML files. You should be using gzipped files anyway with Windows, since downloads are faster.

  • Installing VRMLview under Linux, SGI or Windows
    Place the VRMLview application in a folder such as /local/bin/vrmlview then go to Netscape Edit/Preferences/Navigator/Applications and add it as a new application, making sure to include the full path to it and to add %s after the application name to tell it to read the current input (eg "/local/bin/vrmlview/vrmlview.exe %s"). Define the extension as WRL and the mime type as x-world/x-vrml. VRMLview or ivview can be installed the same way under SGI Irix. For SGI VRMLview has the advantage that it can use compressed VRML files and print JPEG images of the structure display, but ivview is faster and gives a higher quality display. VRMLview also works well under the new Linux browser Konqueror. VRMLview even has some advantages over CosmoPlayer, however it cannot "blink" between different structures to compare them, and there are minor display problems for a few structures (see Back-Face Culling below).

  • Printing the 3D Structure Window
    You cannot print the 3D structure window directly (under VRMLview, you can save a JPEG image). Otherwise you must use the "PrintScreen" key. Enlarge the window to fill the screen for best resolution, then in Windows press the "Alt-PrintScreen" keys to copy just the top window. Paste this into MS-Word or any graphics application, such as the free trial version of Paint Shop Pro for Windows from ZDnet , and print from that application after cropping, selecting the option to fill the whole page.

  • The CosmoPlayer VRML Controls
    Hold down the mouse button over the 3D object and drag the mouse: the left button is used to rotate, the right button to translate, and the "middle button" to zoom. (If you don't have a middle button or if it is not defined as "middle button" in the Windows Control Panel mouse properties, hold down the Ctrl key while dragging with the left button). If the image skates off the page, you may need to choose "Examine" mode. Locate the small Change Controls stick at the bottom left-center of the Cosmo console. Click on this stick to shift it up. (Sometimes you need to click it twice to enter "Examine" mode). Since you can then examine the structure with the mouse alone, you might want to minimise this dashboard console by clicking on the left tab. Move the structure to the center of the window, or zap an atom with the cross-hair tool, to rotate about that point.

  • The VRMLview Controls
    These are similar to those for CosmoPlayer; the right button rotates, the left zooms, and both together (or the middle button) translates. When the first VRML structure is displayed, adjust the size of the window, select View then Filled, Full Model, and Backface Culling On. Also try Settings - Window Buffer Off, otherwise you may need to click in the window to redraw the display.

  • Optimising CosmoPlayer2.1.1
    It is important that you use the latest version for Windows (2.1.1) ! The previous version 2.0 did not include support for MicroSoft's Direct3D, and many graphics cards use drivers optimised for Direct3D. Open the Cosmo Preferences (bottom right of console) and try the 3 options for Graphics: Automatic, Direct3D, and OpenGL. (Press the '=' key to display the frame rate, and rotate the drawing). Experiment with different settings, sizes of window and number of colours set by the Windows desktop. Download and install the latest drivers for your graphics card of course. On a PC, you might try installing SGI's openGL driver which may give an up to 40% speed increase over MicroSoft's Direct3D driver, and is even faster than some hardware graphics cards. Finally, under Preferences-Advanced, select the Virtual Trackball rather than the default Standard Examiner - this makes it easier to rotate the structure !

  • The Speed of the 3D Display
    The speed with which you can rotate 3D objects naturally depends on how complex they are and how powerful your computer is. You will need at least a 75 Mhz Pentium class PC, a Macintosh PowerPC, or a Unix workstation such as a Silicon Graphics O2. The display may be faster if you reduce the size of the window. For $1000 you can now buy a PC that will rival an SGI, with a 3D frame rate higher than many monitor refresh rates for simple structures. Choose one with a modern PC-graphic card eg containing the nVidea G-Force chipset.

  • But what is VRML anyway ?
    You don't need to know what VRML is, but if you are curious, it stands for Virtual Reality Modelling Language. You can learn how easy it is to use for crystallography from the ILL's WWW pages.

    But first look at the pretty pictures of typical structures produced by ICSD-for-WWW.

    Please report any problems to hewat@ill.fr.