3dmodv Stereo Dialog
This window provides control over two or three kinds of stereo displays,
depending on whether the graphics hardware supports stereo. The combo box
allows one to turn a particular kind of stereo on or off, the Angle
slider allows one to adjust the angle of parallax between the two views, and the
Vertical Offset slider allows one to adjust the offset between views in
top/bottom stereo to bring the views into register when the monitor does two
vertical scans per frame.
- This mode is the default when no internal or external hardware seems to
available. Some people may find this useful if they can fuse the two images
- This mode is designed to be used when the monitor can be set to display the top
and bottom of the display in two successive scans. When you activate this mode,
the model view window will be stretched to the full height of the screen and the
model will be shown in the top and bottom of this window. After you switch the
monitor to display two scans, adjust the vertical offset slider until the two
images coincide. Once you have determined this offset, you can define an
environment variable IMOD_STEREO_TBOFFSET to have this value, and this offset
will be applied automatically in the future.
- This mode is available if the display hardware supports left and right
stereo buffers in OpenGL, such as with NVIDIA Quadro cards.
When the mode is activated, the command defined in
the environment variable IMOD_STEREO_COMMAND (if any) is executed. The two images are
then drawn into the left and right buffers. When the mode is turned off, the
command defined in the environment variable IMOD_STEREO_RESTORE (if any) is executed.
These ancillary commands are unnecessary when activating stereo with an NVIDIA
On Macs, hardware stereo is often detected inappropriately and there can be
bad consequences if it is entered inadvertently, or even if the capability is
requested. Thus, by default
stereo is disabled on a Mac.
It can be enabled in the Behavior tab of the 3dmod -
Preferences dialog. If you turn this on and the program crashes when opening
Model View, turn it off again.
Stereo is toggled with the S hot key. The first time this is used, the
program will go into Top/Bottom mode if IMOD_STEREO_TBOFFSET is defined,
otherwise into Hardware mode if stereo buffers are available (except on the
Mac, as just indicated), otherwise into Side-by-side mode.
Stereo Image Display Controls
It is possible to display image pairs in stereo in the model view window using
the controls at the bottom of this dialog. They are enabled when View
Z image is selected in the Image View dialog. The image data can
consist of a single tilt series, or of consecutive sets of tilted views of
different areas. In the simplest case, the image stack would consist of
consecutive stereo pairs. Before activating stereo,
adjust the Tilted views per area spin box to the correct value. For a
tilt series, set this to the number of images in the series.
Turn on Show images as stereo pairs to activate the image display
mode. In this mode, the model and image will not be drawn at different angles
in the left and right displays; rather, two different images will be drawn in
the left and right buffers if possible. The current section will be drawn in
the left buffer and a higher section in the right buffer, but only if the
higher section is a view of the same area.
If you have more than 2 views of each area, adjust
Sections between pairs to select a pair with a different stereo angle.