4.3 Environment Variables

In order to execute Amira no special environment settings are required. On Unix systems some environment variables like the shared library path or the AMIRA_ROOT  directory are set automatically by the Amira start script. Other environment variables may be set by the user in order to control certain features. These variables are listed below. On Unix systems environment variables can be set using the shell commands setenv (csh or tcsh) or export (sh, bash, or ksh). On Windows environment variables can be defined in the system properties dialog (Windows 2000/XP/Vista).

• AMIRA_DATADIR
  A list of data directory names separated by semicolons [;] on Windows systems and colons [:] on Unix systems. The first directory will be used as the default directory of the file dialog. Other directories are quickly accessible via the file dialog's path list.
• AMIRA_TEXMEM
  Specifies the amount of texture memory in megabytes. If this variable is not set some heuristics are applied to determine the amount of texture memory available on a system. However, these heuristics may not always yield a correct value. In such cases the performance of the Voltex module might be improved using this variable.
• AMIRA_MULTISAMPLE
  On high-end graphics systems, a multi-sample visual is used by default. In this way, efficient scene anti-aliasing is achieved. If you want to disable this feature, set the environment variable AMIRA_MULTISAMPLE  to 0. Note that on other systems, especially on PCs, anti-aliasing cannot be controlled by the application but has to be activated directly in the graphics driver.
• AMIRA_NO_LICENSE_MESSAGE
  By default, Amira issues warning messages to the console when your Amira license is about to expire. This allows you to take timely action so that your use of Amira is not interrupted unexpectedly when the license expires. To disable these messages, set this variable to 1.
• AMIRA_NO_OVERLAYS
  If this variable is set, Amira will not use overlay planes in its 3D graphics windows. The same effect can be obtained by means of the -no_overlays command line option. Turn off overlays if you experience problems with redirecting Amira on a remote display, or if your X server does not support overlay visuals.
• AMIRA_NO_SPLASH_SCREEN
  If this variable is set, Amira will not display a splash screen while it is initializing.
• AMIRA_LOCAL
  Specifies the location of the local Amira directory containing user-defined modules. IO routines or modules defined in this directory replace the ones defined in the main Amira directory. This environment variable overwrites the local Amira directory set in the development wizard (see Amira programmer's guide for details).
• AMIRA_SMALLFONT
  Unix systems only. If this variable is set a small font will be used in all ports being displayed in the Properties Area even if the screen resolution is 1280x1024 or bigger. By default, the small font will be used only in case of smaller resolutions.
• AMIRA_XSHM
  Unix systems only. Set this variable to 0 if you want to suppress the use of the X shared memory extension in Amira's image segmentation editor.
• AMIRA_SPACEMOUSE
  This variable has to be set in order to support a spaceball or spacemouse device (see www.spacemouse.com). With the spacemouse you can navigate in the 3D viewer window. Two modes are supported, a rotate mode and a fly mode. You can switch between the two modes by pressing the spacemouse buttons 1 or 2.
• AMIRA_STEREO_ON_DEFAULT
  If this variable is set the 3D viewer will be opened in OpenGL raw stereo mode by default. In this way some screen flicker can be avoided which otherwise occurs when switching from mono to stereo mode. Currently the variable is supported on Unix systems only.
• TMPDIR
  This variables specifies in which directory temporary data should be stored. If not set, such data will be created under /tmp. Among others, this variable is interpreted by Amira's job queue.