Mouse Manipulation of Models
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 three-button mouse
(although fewer buttons can be workable),
Also by default,
- 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, depending on the mouse setup,
an adjustment may be required.
- 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 increase the scale,
whereas movements upward and/or to the left decrease it.
Interactive scaling can also be performed
by rolling a mouse's scroll wheel or by dragging the small square in the
- 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
Mouse button assignments can be changed in the
- Ctrl-left mouse button performs
(selection from the graphics window);
the cursor will look like a pointing hand.
- Placing the mouse cursor close to an atom or bond (without
clicking any buttons) will cause the corresponding label information
to appear. This atomspec balloon behavior can be turned off in the
Additionally holding down the Shift key reduces the speed
(mouse sensitivity) of manipulations in the main window and
Side View by a factor of 10.
other input devices
Activation for Motion
A model must be active (activated for motion)
to move in response to mouse manipulations
or commands such as move and
Models are active by default, but it is necessary to toggle between
activated and deactivated states to move one model relative to another.
Model activation status can be controlled:
One- and Two-Button Mice
On a Mac with a one-button mouse, buttons 2 and 3 can be emulated
with the option and apple (clover) keys, respectively.
For example, click-dragging with the option key pressed
performs XY-translation (assuming default
In Mac OS 10.5 (Leopard), emulation of a 3-button mouse is off by default,
but can be turned on in the Input section of the X11 preferences.
A two-button mouse is also workable.
Starting with the default mappings,
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
or the command scale
instead of with the mouse.
Other Input Devices
Chimera also supports the
input device for Mac and Windows.
Other 3Dconnexion devices such as the SpaceExplorerTM
may also work. The 3Dconnexion driver must be installed.
Besides a cap that can be tilted, rotated, and pushed/pulled in
any direction, the SpaceNavigatorTM
has two buttons with the possible Chimera functions:
The Zoom Direction controls how the cap coordinate system relates
to the screen coordinate system:
- Button 1 or Fit centers the models
and scales them to fit in the window
- Button 2 toggles a mode allowing
simultaneous rotation and translation (the default
only allows rotation or translation depending on which user motion
has the larger amplitude)
Zoom direction and other settings are shown in the
Windows Control Panel or Mac System Preferences, although
some of the Mac controls appear to have no effect.
- when up/down cap motion zooms the models,
the tabletop plane maps to the plane of the screen;
the systems are related by a rotation of approximately 90°
- when closer/farther cap motion zooms the models,
the systems are approximately aligned
(keyboard shortcuts) for changing
Accelerator use must be enabled with
Tools... General Controls... Accelerators On or the
- na - toggle between moving all models and moving only the
- nd - toggle between dominant mode
and allowing simultaneous rotation and translation
- nf - toggle fly-through mode,
where the device moves the viewpoint rather than the models
(as if all axes were reversed); currently hard to control
- nz - toggle whether model in/out motion is true zooming
(scaling the entire scene) or Z-translation (moving models relative
to the front and back clipping planes)
See also: Phantom Force Feedback
UCSF Computer Graphics Laboratory / April 2008