Moving around

The Viewport displays visualization of structural models, visual models, some other nodes, editors and apps, and you can move around in it using a mouse, a keyboard, or the Compass.

Moving around in the viewport

The key element of visualization in SAMSON is a camera, it provides a 3D view of visualizable objects. Basically, you may consider your screen as a camera pointing into the screen and yourself as an operator seeing through the camera. A camera is a part of a SAMSON Document, and each Document has at least one camera. Cameras (their positions and properties) are saved and loaded together with a Document.

You can easily control the camera to point to a specific location, zoom in or out, translate, rotate, etc.

Using the camera

A camera has three modes: rotation, translation, and zoom.

Using a mouse:

  • Right mouse button to rotate the view.
  • Middle mouse button to translate the view.
  • Double-click on the middle button to center the view.
  • Ctrl/ Cmd⌘ + Right mouse button replaces the middle button.

Using a keyboard:

  • - rotate the view around horizontal or vertical axis.
  • Alt + - rotate the view in the viewport plane around its center.
  • Ctrl + - translates the view horizontally or vertically.
  • Ctrl + + - zoom in.
  • Ctrl + - - zoom out.
  • Shift + Space - center the camera on the selection or on the full view if nothing is selected.

Note: The rotation behavior slightly changes depending on whether the grid is on or off. When the grid is on, consider it as a table on which you rotate a system. When the grid is off, consider that you rotate a system that is floating free.

Rotation mode

To switch the camera into a rotation mode, press and hold the right mouse button. There are two rotation modes: close to the borders of the viewport and a trackball rotation mode (the view point is rotating around the center) in the middle part of the viewport.

Translation mode

To switch the camera into a translation mode, press and hold the mouse wheel. Try to move your mouse and you will see that the molecule follows it.

Zoom mode

To switch the camera into a zoom mode, scroll the mouse wheel: turn the wheel and the camera will zoom in and zoom out depending on the direction.


Double-click on the middle button to center the view.

The Shift + Space shortcut changes the camera focus. Select an atom and press Shift + Space, this centers the camera on the selected part (so that the selection will be in focus). If nothing is selected, then the camera is centered on the full view of the molecular system (the whole molecular system in the active Document).

Tip: If you loose your molecular system, press Shift + Space and the camera will be re-positioned.

Tip: If the camera is centered on an atom and you will do the rotation, the rotation will be centered around the atom.


A camera in SAMSON has dedicated camera controller called compass, which is situated in the bottom-left corner of the viewport and can shown/hidden using the Visualization menu or using a menu in the bottom part of the viewport. This compass allows you to easily align the camera and rotate it around different axis.

The camera compass

Accessing camera functions

You can access the camera functionality in the Visualization menu.

The camera functionality in the Visualization menu

You can also access some of the functionality through the camera context menu ( right click on a camera in the document view).

Try, for example, switching on and off the orthographic projection mode.

Multiple cameras

A camera stores its positions and projection. Having several cameras might be useful if you want to switch fast between different views (e.g., positions, projections, close-up views, and a full view) in the same Document. To switch between cameras, double-click on one or select one in the document view and in its context menu click "Set as active camera". Only one camera can be active at a time.

You can have multiple cameras in one Document. Try creating a new camera by pressing the "Add new camera" icon in the Visualization menu or using the Ctrl + Shift + C shortcut on Windows and Linux or Cmd⌘ + Shift + C on Mac.

Several cameras

A newly added camera will have a default starting position.

Context menu for a camera

More camera functions

Through the camera context menu you can also activate the camera inertia which will allow for a movement with inertia of the camera and orthographic projection which is useful e.g. for viewing crystals. Try switching the camera inertia on and move or rotate the molecule.

See camera for more information.