Help with Problems

The position sensor does not respond.

First of all, make sure you are using a correctly wired serial cable between the position sensor and the computer. For the Bird sensor, the cable should connect pins 2, 3 and 5 only, as described in the manufacturer's documentation. Some position sensors take a long time to boot up: if you try and talk to them too quickly after power-on you might break the link and it may be necessary to cycle the power to reestablish it. If you try to use the sensor with the wrong serial port speed you will break communications in a similar way. In all such cases it is best to reboot the sensor and leave it for a few minutes to initialise before trying to poll it with Stradx. When you select a new device in the `Edit setup' panel, Stradx polls the device and tries to work out if it is talking to a Bird, Patriot, Fastrak or Polaris. In order to retry a device address, you should change it to /dev/null and then change it back to the correct address.

Zero recording frame rate.

When position information is being recorded then the most likely cause is that communication with the position sensing device has broken down. The best cure for this is to cycle the power on the position sensing device, give it plenty of time to reinitialise, and then try probing it again from Stradx by selecting the device in the `Edit setup' panel. See the section above that describes how to fix a position sensor that does not respond.

Warning message about low quality display.

Stradx attempts to provide the highest quality graphics display by asking the X server for suitable high quality visuals. If these visuals are not available (because your graphics card does not support them), then Stradx still runs but warns you that the graphics quality may be poor.

Warning message about no model data available (wireframe.data).

If you wish to use Stradx's body registration facilities, make sure the file wireframe.data is installed in the same directory as the Stradx executable: you will also need to specify the full path of the Stradx executable when you run Stradx (ie. do not rely on symbolic links or your shell's search path), otherwise Stradx will not be able to find the wireframe.data file.

Warning message "XtRemoveGrab asked to remove a widget not on the list" .

This is a known problem with old versions of the Lesstif widget library: either ignore the warning, or upgrade to the latest Lesstif release.

Numerical values are not displayed above sliders while they are dragged .

You are running an old version of Lesstif, with a slightly buggy libXm.so.2. Upgrade to the latest version and this problem will go away.

Warning message "QUERYCAP ioctl in construct_v4l2_buffer failed: Invalid argument" .

You may be running the wrong version of Stradx for your `Video for Linux 2' installation. Try running the other version. Alternatively, you may be running `Video for Linux' instead of `Video for Linux 2'.

Rendering errors with accelerated graphics cards .

Several XFree86 and X.org distributions shipped with buggy direct rendering drivers. Consequently, you might see rendering artefacts in Stradx's various graphics windows. You can either tolerate these errors, or disable direct rendering by running Stradx as follows: LIBGL_ALWAYS_INDIRECT=1 stradx &

Segmentation faults when opening/closing graphics windows .

Some direct rendering drivers no longer seem to cope well with mutliple graphics contexts (they used to work fine). If Stradx crashes with a segmentation fault when you open or close a graphics window, disable direct rendering by running Stradx as follows: LIBGL_ALWAYS_INDIRECT=1 stradx &