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Labeling

A label is a type of a node that is stored in the document and depicts some text in the Viewport. A label can contain a node's name, a text describing a group of nodes, or some measurement.

In this section, you will learn how to add labels and modify them (change their visibility, font, color, and positions).

Labels example

Note

If you save your document in one of the SAMSON file formats (.sam or .samx), labels will be saved as well.

Prerequisites:

  • Please refer to the Selecting section to learn how to select nodes in SAMSON.
  • Please refer to the Inspecting section to learn how to inspect nodes in SAMSON.

Adding labels#

You can add labels to selected nodes via their context toolbar.

Note

Labels cannot be added to all types of nodes but mainly to structural nodes (molecules, residues, atoms, etc).

Adding labels to selection#

To add labels to selected nodes, in the context toolbar, choose label command:

  • "Add label" - this will add a single label for the currently selected group of nodes (this does not add labels to descendants of the selected nodes but only to the directly selected group of node).
  • "Add label to..." - you can choose to what type of nodes to add labels, including descendants of the currently selected nodes, for example to all the residues in the current selection.

Add labels via the context toolbar

Adding labels in Viewport#

To add labels in the Viewport, first, you need to activate the Label editor (label editor) in the left-side menu of the viewport or via shortcut Ctrl/Cmd + L.

Please note, that the type of node to which a label will be added depends on the current SelectionFilter. For example, if it is set to "Atoms and bonds" then labels will be added to atoms or bonds, if it is set to "Residues" then labels will be added to residues.

Visibility of labels#

You can switch on/off the visibility of labels in the Document view by ticking/unticking them.

The visibility of labels changes progressively when zooming in and out on the system. When zooming out, the labels for smaller nodes (e.g., atoms) will start to disappear and the labels for larger nodes (e.g., molecules) will start to appear, and vice versa when zooming in.

You can modify when labels appear and disappear. For that, select a label and, in the Inspector, change maximum and minimum display radii - these parameters govern when the label is visible.

Changing font of labels#

You can modify the font for all the labels or just for a group of labels.

To modify the font for all the labels for which the font has not been specified directly, open the Preferences > Rendering > Labels and change it there. You can also modify there the number of decimal places for angles and distances shown in labels which is useful for labels created using the Measure editor.

The labels preferences

To modify the font for a label or a group of labels, select them and open the Inspector. In the Inspector, click on "Choose font..." to modify the font for the last selected label or for all selected labels at once if you choose to Edit all selected nodes.

To reset the font for labels to the one specified in Preferences, select these labels and, in the Inspector, double-click on the "Font" as shown in the image below.

Reset label's font

Colorizing labels#

Labels can be colorized as many other nodes.

You can change the color of a label as follows:

  • click on a label in the Document view, then, in the context toolbar, go to pick color scheme Color > Constant and choose a color from the pop-up dialog.
  • select a label and in the Visualization > Color pick color scheme click on Constant.
  • select a label and in the Inspector click on Color > Constant:

Set color in Inspector

You can reset the label's color to the default one in the same way.

  • click on a label in the Document view, then, in the context toolbar, go to pick color scheme Color > Reset color.
  • select a label and in the Visualization > Color pick color scheme click on Reset color.
  • select a label and in the Inspector click on X (clear) button next to the Text color:

Reset color in Inspector

You can also modify the transparency of labels in the Inspector.

Selecting labels in Viewport#

Apart from selecting labels in the document, you can select them in the Viewport as well.

The level of selection in the Viewport is governed by the SelectionFilter, so first you need to set it to "Labels" and only then you can select labels in the Viewport.

Selecting labels in the Viewport

Note

Only the visible labels will be chosen.

Do not forget to switch the SelectionFilter if you want to select other types of nodes in the Viewport later.

Moving labels#

Prerequisites: Please refer to the Moving objects section to learn how to move objects in the viewport.

When labels are created they are placed at the geometric center of the nodes and they are always situated in the Viewport plane.

You can move labels using one of the following ways.

  1. Select a label and change its viewport offset in the Inspector. Move a label by changing its viewport offset in the Inspector
  2. Set the SelectionFilter to "Labels" and use one of the Move editors, e.g. the Displace editor (Displace editor, shortcut: D). Do not forget to switch the SelectionFilter if you want to select other types of nodes in the Viewport later. Move a label with the Displace editor
  3. Select a label in the Document view and use one of the Move editors. Move a label with one of the Move editors