VMD 1.8.7 Windows Release Notes
Windows Installation Requirement:
- Windows XP or Windows Vista as the base operating system.
- VMD requires a pentium class machine with approximately 256MB of RAM, and a 16-bit color video as a minimally useful configuration. The use of a fast OpenGL hardware accelerated video card is highly recommended.
Installation notes and solution to common problems:
- Conflict with CCP4 Tcl/Tk libraries: It has recently been discovered that CCP4 installs a set of Tcl/Tk dynamic link libraries as part of its install process. Unfortunately, as part of the install, the system-wide dynamic link library search path is modified so that the libraries installed for CCP4 override (in this case interfere) with any other libraries on the system. This results in VMD crashing at startup. Removing the CPP4-related Tcl/Tk libraries from the system-wide default search path, or uninstalling them will cure the problem. We will be contacting the CCP4 team to advise them of the problems their installer is causing other Tcl/Tk apps like VMD, and arrive on on a mutually agreeable solution.
- Installation on Windows Vista systems that deny unsigned applciations Depending on the existing Windows Vista administration settings, it may be necessary to temporarily disable the "UAC" or user account controls off for the administrator user. With this done and followed by a reboot, VMD can then be installed on the affected machine. Once installed, the Vista UAC system can be enabled again. Various Windows Vista installation tips are available at this site
- Using MSMS on Windows In order to use MSMS on Windows, a new environment variable named MSMSSERVER must be set, in the Windows control panel "System" window. The value of this new environment variable must contain the full pathname of the MSMS binary that you've installed on your computer, e.g.: c:\program files\some\directory\msms.exe This is done using the Windows control panel "System" window, and adding the new environment variable using the "advanced" tab, opening the "environment variables" window from there, and adding the new MSMSSERVER variable, with the value set to your MSMS binary path as above.
- Stability issues, corrupted graphics, video driver bugs: If you install VMD successfully, but the program crashes at startup, or behaves erratically, there's an extremely high probability that you have a buggy graphics device driver installed. While extreme forms of these symptoms are a rare occurence, it has been known to happen with computers purchased coincident with the release of brand new graphics chipsets, when drivers are the most buggy. Some users have owned machines for a year and never updated their drivers, and so the first time they run VMD, it encounters the old/buggy driver, sometimes leading to a crash, garbled images on the display, or other symptoms. This is particularly true of video drivers that have sub-standard implementations of OpenGL Shading Language. This type of problem can typically be immediately remedied by visiting the video card vendor's web site and downloading and installing their most up-to-date drivers for your graphics board. (e.g. the ATI, Intel, or NVIDIA web driver update web sites.) If all else fails, it is possible to enable a system-wide environment variable in Windows which will cause VMD to avoid using any advanced OpenGL graphics features, using a minimalistic "safe subset", which will reduce performance but increase stability. This mode can be enabled by adding and setting the environment variable "VMDSIMPLEGRAPHICS" to "1" in the control panel "System Properties" window, in the "Advanced" tab.
- Support for GLSL rendering mode
VMD 1.8.7 uses OpenGL Shading Language shaders written for the version 1.10 version of the standard (now a few years old). Some early GPUs which are now 3 or 4 years old may not support the entire GLSL standard, and thus will not allow the use of GLSL shading with the standard VMD shaders. The most significant change to the VMD GLSL shaders is that they now require support for the gl_FrontFacing shader attribute. GPUs which do not support gl_FrontFacing will not be able to run the most recent versions of VMD in GLSL mode. If you have one of these older cards and would like to use GLSL (with some shading artifacts as a result of the hardware limitations) we can provide you with a special version of the VMD shaders. NVIDIA provides a GLSL compatibility document which describes what features are supported on the various hardware and driver versions: NVIDIA GLSL Release Notes
- Windows Vista Performance (Jan 29, 2007): Tom's Hardware article summarizing early experiences with Vista performance versus XP.
- Windows Vista OpenGL Performance (Feb, 2007): The OpenGL ARB has posted an article which describes performance issues and their implications resulting from the new Windows Vista display driver model, and the new "Aero" desktop.
- Windows Vista OpenGL Performance (Jan 29, 2007): Tom's Hardware performance test of Windows Vista graphics drivers The majority of these performance results apply equally to VMD as they do to the video games used in the tests.
- Windows Vista and stereoscopic display: Initial indications seem to be that Windows Vista will not provide support for stereoscopic display. See the commentary in the 'Two things to watch out for' section of the "NVIDIA: OpenGL on Vista" Siggraph presentation posted here: http://www.khronos.org/developers/library/siggraph2006/OpenGL_BOF/
Stereoscopic Display Information
- VMD supports quad-buffered frame sequential stereo rendering. Specific information on setting up stereo on PC's can be found among the several links from the web site below. Many of the low-end stereo solutions are not currently capable of working within VMD, but we have are evaluating adding such support into VMD. The web sites below contain good discussions of the hardware and software compatibility issues for stereo, particularly for PC's running Windows.
- REAL D (formerly StereoGraphics)
- Scitech GLDirect
Limitations of the Windows version of VMD
- The Win32 versions of VMD do not include Python yet, for reasons explained here, and on the Python web site.