3D Renderer

Settings

images/renderer-settings.png

The orange "R" button in the toolbar provides access to renderer settings (which are applied to the 3D rendering widget), such as:

• "Show slicers" (default: false) - determines whether the slice axes are also applied in the 3D renderer, meaning that the 3D volume will be cut along each axis at the position currently selected in the respective slicer. Slice direction can be reversed through 'x', 'y' and 'z' keys when the 3D renderer dockwidget has the focus.
• "Show helpers" (default: true) - determines whether to show the cube indicating axis directions as well the colored axes and the logo widget.
• "Show position" (default: true) - shows a red cube indicating the current position of the mouse in the slicer (only updated when "Link Views" option in slicer settings is also enabled!)
• "Linear interploation" (default: true) - whether rendering should use linear interploation (less block artefacts, but picture can look blurry)
• "Shading" (default: true) - whether to use shading in 3D volume rendering (light options below are to a large extent only applicable if shading is enabled)
• "Sample Distance" (default: spacing of the image) - distance of rays used for 3D volume rendering (the smaller the number, the more rays are used, and thus the better the image quality, but also the slower the computation).
• "Ambient lighting", "Diffuse lighting", "Specular lighting", "Specular power" (default: 0.2, 0.5, 0.7, 10) - parameters to the shading/lighting model used for volume rendering
• "Background top" (default: #7FAAFF), "Background bottom" (default: #FFFFFF) - colors used for the renderer background (gradient from top to bottom)
• "Renderer type" - mode used for volume rendering. Typically you should use Default/GPU renderer, as it is faster, but in some instances, you may want to try RayCastRenderMode.

Key Commands

When the 3D renderer window is highlighted (click on it once to highlight it), these key commands are available:

• 'r' resets the view
• 'j' switches to joystick navigation mode
• 't' switches to trackball navigation mode
• 'a' switches to actor modification mode (a single volume or polygon will be modified through the interaction)
• 'c' switches to camera modification mode (interaction will modify the camera perspective)

When the "Show slicers" mode is enabled (see rendering settings, above):

• pressing the 'x', 'y' and 'z' keys will switch the cutting direction of the respective axis ('y' will for example switch the slicing direction in the xz-plane).