3D Views

Dragonfly offers the opportunity to view objects in both perspective and orthographic projection modes. In the familiar and default perspective mode, objects are subject to foreshortening and will appear smaller as their distance from the camera increases. In the parallel projection of orthographic mode, there is no foreshortening or vanishing point and dimensions can be communicated unambiguously.

Although perspective viewpoints can provide more information about depth and often tend to appear more realistic, orthographic viewpoints can make it much easier to compare objects, such as the parts of a molecule, as there is no question about how the viewpoint may affect the perception of distance or size. In addition, a scale bar is available for orthographic views (see Scale Bar for Orthographic Projections).

Perspective (on left) vs orthographic (on right) projections

While working, you can easily switch between orthographic and perspective modes to get a better sense of an object. Orthographic projection mode is selectable on the Scene’s Views Properties panel and in the pop-up menu for 3D views. You can also choose Orthographic as the default projection mode (see Selecting the 3D Settings Preferences).

The Axis Indicator, which can be shown as a cube or axes, displays the orientation of the current view.

Axis Indicator styles

You can show or hide the Axis Indicator, as well as choose its style, as follows:

• Right-click the required 3D view and then choose Axis Indicator in the pop-up menu.
• Choose Cube, Axis, or None in the submenu, as required.

The text annotations show information about the current image in the 3D view, such as the window level values. These annotations are interactive and can be used to adjust the view, as described in the following table. See Selecting the Fonts Preferences for information about customizing the appearance of the text annotations.

Description of the text annotations

	Description
X by Y (size) or PD (distance to the camera's pivot point)	Indicates the dimensions of the 3D view when you are in Orthographic view mode, or the distance to the camera pivot point for perspective views.   Orthographic projection   Perspective view Drag up or down from the annotation to adjust the applied zoom factor.
Window Leveling	Indicates the current window leveling applied to the selected image data. You can choose to display the window width (W) and window center value (C), as shown below on the left, or the minimum and maximum values of the selected range, as shown below on the right. These options are available as a preference (see Miscellaneous Preferences). Drag the annotation left and right to change the threshold values; drag up and down to change the center value. See Window Leveling for additional window leveling options.

Legends are available for 3D views to show how values are mapped to the grayscale tones of image data and to the colors of scalar data. If required, you can re-position the legends by dragging them anywhere inside a view. You can also position a legend vertically or horizontally.

Legends

Do the following to change the orientation and/or size of a legend:

• Right-click the legend and then choose Vertical or Horizontal in the pop-up menu.

  You can choose a default orientation for legends in the 2D Settings preferences (see Selecting the 2D Settings Preferences).

• Drag from the start or end point of a legend, as shown below, to change its width or height.

  

Two active view icons — Camera and View — are available for the current 3D view.

• The Camera icon lets you export multiple screenshots or copy a screenshot of the current view to the clipboard (see Taking Screenshots).
• The View icon lets you drag the display's GUID to the Python Console.

A floating scale bar is available for 3D views showing orthographic projections (see Perspective and Orthographic Projection Modes) to show the relative size of an object. If required, you can re-position the scale bar by dragging it anywhere inside the view.

You can also set its length as follows:

1. Right-click the scale bar and then choose Set Specific Length in the pop-menu.
2. Enter the required length in the dialog that appears onscreen.

   To reset the scale bar, right-click and then choose Set Default Length in the pop-up menu.

A right-click or pop-up menu for 3D views provides access to the Movie Maker panel, macros, and to the different views available for the displayed data.