Mouse Manipulation of Structures
The X axis is horizontal in the plane of the
screen, the Y axis is vertical in the plane of the screen, and the
Z axis is perpendicular to the plane of the screen.
By default, using a 3-button mouse
(see below if dealing with a 2-button mouse),
- rotated with the left mouse button
in the graphics window. Rotation is about the
X and/or Y axis when the cursor is in the central region
of the graphics window (the cursor becomes a small circle) and
about the Z axis when the cursor is in the periphery of the
graphics window (the cursor becomes two curved arrows in yin-yang
configuration). The center of rotation can be adjusted with the
Rotation tool or the command
- XY-translated with the middle mouse button
(the cursor will look like a cross formed by two double-headed arrows).
On Windows systems, depending on the mouse setup,
an adjustment may be required.
- Z-translated with Ctrl-middle mouse button (the cursor will look
like a vertical double-headed arrow);
movements downward and/or to the right translate
structures closer, and movements upward and/or to the left
translate structures farther away. Note that Z-translation is not the same
as scaling (below).
- scaled with the right mouse button (the cursor will look
like a diagonal double-headed arrow enclosing a small square);
movements downward and/or to the right enlarge structures (increase the scale),
and movements upward and/or to the left shrink them (decrease the scale).
Scaling can also be performed using the mouse
within the Side View,
or by entering a specific scale factor with the
scale command in the
Selection of atoms and bonds
from the graphics window is also called picking.
During picking (by default, Ctrl-left mouse button),
the cursor looks like a pointing hand.
Models that have been deactivated
for motion cannot be translated or rotated with the mouse or commands.
The mouse button assignments can be changed in the
Note that holding the Shift key down will reduce the speed
(mouse sensitivity) of manipulations in the main window and
Side View by a factor of 10.
Finally, if Show atomspec balloon is set to true in the
General preferences, placing the cursor close to
an atom or bond will cause the corresponding label information
to appear and remain until the cursor is moved away.
Dealing with a Two-Button Mouse
While it is best to have a three-button mouse, a two-button mouse is workable.
If the right button of a two-button mouse is not already
performing XY translation, use the
to reassign XY translation to button 3. The right button of a
two-button mouse should then work for XY translation, leaving
the left button for rotation (the default).
Scaling can be performed with the
and the command scale.