Webots - General

Q: What are the differences between Webots PRO, Webots EDU and Webots DEMO ?
A: Webots PRO is intended for research purposes, Webots EDU is intended for education purposes and Webots DEMO is a free version limited to a series of programming contests.

Q: I found a bug in Webots, what shall I do ?
A: Send a complete bug report from http://www.cyberbotics.com/bug/ including a precise description of the problem, the sequence of actions necessary to reproduce the problem. Please attach the world file and the controller programs necessary to reproduce the problem.

Q: Which graphics card are best suited for use with Webots ?
A: Any recent nVidia or ATI graphics card with 128MB RAM (or more) should be fine, as they include good OpenGL support. If you don't have an OpenGL accelerated card, Webots will run slowly.

Webots - Windows

Q: On which version of Windows will Webots work best ?
A: Webots works well on any recent version of Windows, including Windows Vista and Windows XP.

Q: Is it possible to use Visual C++ / Borland C++ to compile my controllers ?
A: Yes, however, you will need to create your own project with all the necessary options (include and library paths, libraries, etc.) and create the import libraries specific to your compiler. To create the import libraries (the *.lib files in Visual C++) from the *.dll files of the lib directory of Webots, please follow the instructions provided with the documentation of your compiler. We only support the mingw / gcc environment.

Q: Webots displays an error message saying it could not locate an ordinal number in a specific dynamic link library file, like jpeg.dll or other.
A: This problem comes from the fact that you installed an older (or different) version of this dynamic link library, probably coming with another software installation. Do a file search with that file name, like "jpeg.dll" and you will find probably several versions of this DLL. To fix this problem, you must identify which DLL is used by Webots. Normally, it is located in a directory which is in your PATH environment variable, like C:\Windows\system32. Once you found it you can either:
(1) Copy the DLL provided within Webots over this DLL file (This **should** not break the functionality of another program, since DLL libraries should have ascedant compatibility, but you never know...). Please keep a copy of the original file, so that you can revert to the previous configuration if it makes problems.
(2) Change you PATH environment variable, and add the path to the Webots DLL, so that it is loaded instead of the other one (same possible problem as above).

Webots - Linux

Q: Which version / distribution of Linux is recommanded for use with Webots ?
A: Webots will work on any recent Linux distribution. Please be sure to install the latest nVidia or ATI OpenGL linux drivers if you have an nVidia or ATI graphics card.

Q: Webots displays a warning at startup: Xlib: extension "XFree86-DRI" missing on display ":0.0".
A: If you installed a nVidia driver, you should make sure that all soft links in /usr/lib/libGL.so* and /usr/X11R6/lib/libGL.so* point to the /usr/lib/libGL.so.1.0.???? library from nVidia.

Q: Webots graphical user interface behaves strangley under SuSE 9.1.
A: simply delete your .gtkrc file (or reset it to use the Default theme).

Q: I have problems running Webots on a remote X display: GLX errors. How can I sort that out ?
A: This problem is not specific to Webots but to any OpenGL application. There are some known incompatibility issues with GLX (OpenGL on the X Window system) across Linux, Solaris and Windows X servers, especially if your Linux, Solaris or Windows machine has a 3D accelerated GLX driver.
This problem might be fixed by installing newer GLX drivers and/or X servers on both sides. X servers with the same version number will likely work better together. But this might not work in all cases (depending on the 3D hardware you have on both sides and versions availability).
Another solution is to install Mesa OpenGL on the Linux side (or on both sides). This solution has the disadvantage of using software 3D rendering and is slower than hardware 3D rendering, but it should work in any cases.
Lastly, it might be possible to configure X on Linux and / or Solaris / Windows, to bypass the GLX protocole and use only the X procole which will yield to a slower performance but might work.
All this configuration work is pretty tricky and you should ask a system engineer if you don't feel comfortable about it.