Navigating the Interface

Efficient navigation is essential for productive 3D image analysis. This tutorial covers workspace layouts, view synchronization, and navigation techniques that allow you to examine volumetric data from any angle and at any scale.

Estimated time: 20 minutes

Prerequisites:

• Completed Getting Started tutorial
• A volumetric dataset loaded in Volvicon

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Workspace Layouts

Volvicon provides predefined layouts to match different analysis tasks. Access layouts from the View tab in the Layout section.

Standard Layouts

Layout	Description	Best For
Conventional	3D view with three orthogonal slices	General analysis, multi-planar review
3D Only	Maximized 3D view	Surface inspection, presentations
Four Up	3D in upper-right, slices in other quadrants	Balanced viewing
Four Down	3D in lower-right, slices in other quadrants	Alternative arrangement

Specialized Layouts

Click More in the Layout section for additional options:

• Single Slice Layouts — Focus on one anatomical plane (Axial, Coronal, or Sagittal)
• Two-Panel Layouts — Combine one slice view with the 3D view
• Slice Views Only — Remove the 3D view for pure 2D analysis

Layout Selection

Use Conventional layout for most work. Switch to 3D Only when focusing on surface models, or to single-slice layouts when performing detailed 2D segmentation.

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Slice View Navigation

The three orthogonal slice views show cross-sections through your volume:

• Axial (Top) — Horizontal slices from -Z to +Z
• Coronal (Front) — Frontal slices from -Y to +Y
• Sagittal (Right) — Side slices from -X to +X

Basic Navigation

Action	Control
Scroll through slices	Mouse wheel
Pan the view	Middle-click + drag
Zoom	Right-click + drag
Reset view	Press R

Scrolling Behavior

When you scroll in a slice view:

• The slice position changes along that view's axis
• The current slice number appears in the view corner
• Other views update to show the intersection point

Synchronized Navigation with Crosshair

The Crosshair feature synchronizes navigation across all views:

1. Navigate to the View tab.
2. Click Crosshair in the Slice Views section to enable it.
3. Middle-click anywhere in a slice view or in the 3D view to set the crosshair position.
4. All views jump to show the selected point.

The crosshair appears as intersecting lines in each view, indicating where the other two planes cross.

Quick Positioning

Hold Alt and move the mouse in any slice view to dynamically update the crosshair position without clicking. This allows rapid exploration of the volume.

Linked Slice Views

Enable Link Slice Views from the View tab to synchronize zoom and pan across all slice views. When linked:

• Zooming in one view zooms all views equally
• Panning in one view pans all views by the same amount

This is useful when comparing the same region across different orientations.

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3D View Navigation

The 3D view provides interactive visualization of volumes, surfaces, meshes, measurements, and primitives (ROIs).

Camera Controls

Action	Control
Rotate	Left-click + drag
Pan	Middle-click + drag
Zoom	Mouse wheel or Right-click + drag
Reset view	Press R

Standard View Orientations

Quickly orient the camera to standard anatomical or engineering views:

Key	View Direction
X	Right side (+X)
Shift + X	Left side (-X)
Y	Front (+Y)
Shift + Y	Back (-Y)
Z	Top (+Z)
Shift + Z	Bottom (-Z)
I	Isometric (diagonal)

These shortcuts are available when the 3D view has focus.

Setting the Center of Rotation

By default, the camera rotates around the scene center. To rotate around a specific point:

1. Position your mouse over the point of interest.
2. Press C to set the center of rotation.
3. Rotate the view—the camera now orbits around that point.

This is particularly useful when examining detailed features on a surface model.

Projection Modes

Toggle between perspective and parallel projection:

• Perspective — Objects appear smaller with distance (realistic)
• Parallel — Objects maintain size regardless of distance (technical)

Press V to toggle between modes, or access the setting from View → Camera → Camera Settings.

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Window/Level Adjustment

Window and Level control how intensity values are mapped to displayed grayscale:

• Level — The center intensity value (brightness)
• Window — The range of intensities displayed (contrast)

Using the Window/Level Panel

1. Navigate to View → Window/Level to open the control panel.
2. Select a Preset for common tissue types:
   • CT Bone, CT Soft Tissue, CT Lung, etc.
3. Or adjust manually:
   • Drag the Level slider to shift brightness
   • Drag the Window slider to change contrast
4. Click Auto to calculate optimal values from the data
5. Click Full Range to display the complete intensity range

Lookup Tables

Lookup Tables (LUTs) map intensity values to colors instead of grayscale:

1. In the Window/Level panel, expand the Lookup Table dropdown.
2. Select a color map (e.g., Rainbow, Hot, Cool, Jet).
3. The slice views update to show the colored representation.

Color maps are useful for:

• Highlighting intensity gradients
• Visualizing analysis results
• Creating presentation images

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3D Clipping

Clipping allows you to hide portions of the 3D scene to reveal internal structures.

Enabling the Clipping Box

1. Navigate to View → 3D Clipping.
2. Click Enable to activate clipping.
3. Click Show Box to display the clipping region boundaries.

Adjusting the Clipping Region

With the clipping box visible:

1. Drag the face handles to resize the clipping region along each axis.
2. Drag the edges or corners to resize multiple faces simultaneously.
3. Objects outside the clipping box are hidden.

Clipping Options

Option	Effect
Invert	Shows content outside the box instead of inside
Reset	Returns the clipping box to encompass all visible objects

Cross-Section Views

Use clipping to create cross-section views of surfaces and volume meshes. Position the clipping box to cut through the region of interest, revealing internal structure.

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Scene Orientations

Volvicon supports different orientation conventions for medical and engineering applications.

Changing Orientation Presets

1. Navigate to View → Scene → Orientations.
2. Select from available presets:

Preset	Convention
Standard	Engineering orientation
Classic	Traditional 3D coordinate system
Medical 1	Radiologist convention (patient facing viewer)
Medical 2	Neurologist convention (patient facing away)

The orientation affects:

• Axis labels in all views
• View direction names (Axial, Coronal, Sagittal)
• Slice scrolling direction

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Cine Loop Playback

The Cine Loop feature plays the stored 4D frame sequence of the active volume object:

1. Navigate to View → Scene → Cine Loop.
2. The playback panel opens with controls:
   • Play/Pause — Start or stop automatic playback
   • First/Previous/Next/Last — Navigate frame by frame
   • FPS — Adjust playback speed
   • Frame slider — Jump to specific positions

Cine loop is useful for:

• Examining 4D datasets (time series)
• Creating animations for presentations

note

In the current release, 4D playback is limited to volume objects. Masks, surfaces, and volume meshes do not provide synchronized 4D playback.

warning

If the active volume geometry is changed after 4D import, Volvicon clears the stored cine frames and keeps the current active volume image.

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Voxel Information Display

Enable real-time voxel information to see intensity values under your cursor:

1. Navigate to View → Slice Views → Voxel Information.
2. As you move the mouse over slice views, the status bar displays:
   • Voxel coordinates (X, Y, Z position)
   • Intensity value at the cursor location

This is valuable for:

• Identifying appropriate threshold values
• Verifying intensity ranges
• Locating specific coordinates

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Customizing Object Display

Surface Representation

Change how surfaces and volume meshes are displayed:

Mode	Description
Solid	Filled surfaces with lighting
Solid Edges	Filled with visible triangle edges
Wireframe	Triangle edges only
Points	Vertices only

Toggle representations from View → 3D View or using keyboard shortcuts:

• S — Solid
• E — Solid Edges
• W — Wireframe
• Q — Points

Surface Shading

Control lighting calculations for surfaces:

Algorithm	Appearance
None	Flat, unlit appearance
Flat	Uniform shading per triangle
Gouraud	Smooth shading across vertices
Phong	Smooth with accurate highlights
PBR	Physically-based realistic rendering

Access shading options from View → 3D View → Surface Shading.

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Object Widgets

Object widgets provide visual references in the 3D view:

Widget	Shows
Outline	Bounding box around visible objects
Corner Outline	Corner markers only
Slice Planes	Where 2D views intersect the volume
Axes Planes	Reference planes along principal axes

Enable widgets from View → 3D View dropdown menus.

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Practical Exercise

Practice these navigation techniques:

1. Load a volumetric dataset and set the layout to Conventional.
2. Enable the crosshair and middle-click in different views to explore the volume.
3. Adjust Window/Level using both the panel and interactive dragging.
4. Enable 3D clipping and adjust the box to reveal internal structures.
5. Practice standard views using keyboard shortcuts (X, Y, Z, I).
6. Change surface representation to wireframe and back to solid.

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Keyboard Shortcut Reference

Slice Views

Shortcut	Action
Mouse wheel	Scroll slices
Middle-click + drag	Pan
Right-click + drag	Zoom
R	Reset view
Middle-click	Set crosshair position
Alt + move	Dynamic crosshair

3D View

Shortcut	Action
Left-click + drag	Rotate
Middle-click + drag	Pan
Mouse wheel or Right-click + drag	Zoom
R	Reset view
C	Set center of rotation
V	Toggle perspective/parallel
X / Shift+X	Right / Left view
Y / Shift+Y	Front / Back view
Z / Shift+Z	Top / Bottom view
I	Isometric view
S / E / W / Q	Surface representation modes

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Next Steps

With navigation mastered, continue to:

• Working with Volume Data — Learn image processing and transformation
• Threshold Segmentation — Create segmentation masks