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
- 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
- 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
- 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
- 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 &