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General tips and hints for BALLView

This page gives hints for BALLView, which do not fit somewhere else...

View molecules in 3D stereo

BALLView provides two different ways to view molecules in 3D: Stereo with shutter glasses and side-by-side stereo. Both can be switched on in the menu entry "Display->Stereo".

When BALLView is running in a 3D Stereo modus, users can change the eye distance of the both viewpoints by using the cursor keys left and right. Left decreases the eye distance and right increases it. The Shift-modifier boosts the effect of the two keys. The optimal eye distance varies for every person and view, so it must be adjusted manualy. The amount of the eye distance can also be changed in the Preferences:



The focal distance seems to have no effect on most viewers, so its settings may be removed for future releases of BALLView.

Caveat: Since for 3D viewing two seperate images have to be created for every camera movement, the 3D performance can drop to half, while rotating or zooming the view. Consider buying a fast graphics accelerator card if you want use this feature.

Shutter glasses

To use shutter glasses with BALLView, you have to use a quad buffered graphics accelerator card. This has up to now only been tested with a NVIDIA Quadro cards, but should also work well e.g. with ATI Fire cards. If you make any experiences in this field with BALLView, please let us know...

Side by side

For side by side stereo viewing the following hardware is needed:
  • two projectors with the same brightness, which project to the exactly same spot
  • polarisation filters to fit on them
  • special polarisation glasses
  • a silver coated canvas
But this form of stereo projection does not require a specific type of graphics accelerator cards.

Visualise hydrogen bonds

To visualise hydrogen bonds, BALLView first has to calculate their position. This can be done, by highlighting a System and clicking on the menu entry "Tools->Calculate H-bonds" (ALT-N). Then a new Representation for them has to be created, while using the model "H-Bonds". The result could look like:

Usage of the POV-RAY export

POV-Ray is an external rendering program which is freely available. The POV-Ray files which were created by BALLView contain the command line, with which POV-Ray should be invoked to render the image. This line could look like:
povray +Imy.pov +FN +Omy.pov.png +QR +W1037 +H922 -UV
To use antialiasing in POV-Ray, the flag "+A0.3" can be added.

Create animations

BALLView can create fly by animations from the Scene, either for creating on screen presentations of for exporting images, for creation of movies (see below). All functionality for this feature is called in the menu entry "Display->Animations":

With the entry "Record" BALLView stores the subsequent sequence of viewpoints in the Scene. This means, if a user moves the mouse, so that the viewpoint changes, this is recorded and can be reproduced. This is done by calling the menu entry "Start". The animation can be stoped any time, by clicking "Stop". "Clear" means, that the recorded sequence is deleted and a new one can be recorded. Click again on "Record" to switch recording off.
The last three entries can be switched on and off to repeat the animation or export images either directly in the PNG format or throught the POV-Ray renderer.

Create movies from pictures

To create movies from a set of images on Linux we suggest useage of the GNU program mencoder, which is freely available for Linux, MacOS and Windows. To create an AVI video with 25 frames per second from all PNG images in the current directory with the codec XviD and a bitrate of 1600 kbit/s invoke

mencoder "mf://*.png" -mf fps=25 -o out.avi -ovc xvid -xvidencopts pass=1:bitrate=1600

For Windows users we recommend the free software VirtualDub.

Usage of distance grids

You might wonder what a distance grid should be good for (see Menu entry "Tools->Distance Grid"). This creates a grid with the distance of every point in the grid to the center of the molecule. This grid can be used to color surfaces according to the distance of every triangle to the center of the molecule, which can create quite nice coloring effects. (see also here)


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