====== X-ray Windows ======



The X-ray windows display the X-rays of each view, as well as POIs, POI trails, reference frames, and landmarks. The //Points of Interest// widget lets you choose which POIs and POI trails to display on the X-rays. The //View// menu has commands for toggling the display of the reference frame and landmarks of the current object, and the POIs of all of the other objects.

{{:L3D_2DViewer.png}}

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The following mouse and keyboard commands can be used in the X-ray windows:

**Left mouse key**: digitize POI (weighted center).
**Ctrl-Left mouse key**: digitize POI (exact coordinates).
**Esc**: cancel POI digitization.
**Alt**: show weighted center as calculated from current cursor position (prospective position of current POI).
**PgUp/PgDn**: moves to the previous/next reporting time.
**Home/End**: moves to the first/last reporting time.
The **mouse wheel** zooms the X-ray image in and out.
**Arrow** keys translate the X-ray image in image plane.
Press and hold the **middle mouse button** to pan the X-ray image within the window.
**R** resets the position of the X-ray image in the window.
Press and hold the **left mouse button** to change the X-ray image contrast (move cursor left/right) and brightness (move cursor up/down).
**Shift-R** resets the image brightness and contrast.
**I** toggles the display of on-screen image info.
**H** toggles the display of on-screen help text.