Render Properties

The Render Properties tool controls how volume data is visualized in the 3D and 2D views. Adjust window/level settings, apply color lookup tables, and configure rendering modes to highlight specific features in your data.

Accessing the Tool

1. Navigate to the Image tab in the ribbon.
2. Click Render Properties in the General section.

Alternatively, double-click on a volume object in the Object Browser.

Window/Level Adjustment

Window and level (also known as window width and window center) control the mapping of voxel intensities to display brightness.

Parameter	Description
Window (Width)	The range of intensity values displayed. Smaller values increase contrast.
Level (Center)	The midpoint of the displayed intensity range.

tip

For CT images, use standard presets:

• Bone: Window 2000, Level 500
• Lung: Window 1500, Level -600
• Soft Tissue: Window 400, Level 40
• Brain: Window 80, Level 40

Adjusting Window/Level Interactively

• Hold Right Mouse Button and drag in any 2D slice view:
  • Horizontal movement adjusts Window (width)
  • Vertical movement adjusts Level (center)

Color Lookup Tables

Apply color maps to visualize intensity values using different color schemes:

Lookup Table	Use Case
Grayscale	Standard medical imaging display
Rainbow	Visualizing continuous gradients
Hot/Cold	Highlighting temperature or intensity variations
Custom	User-defined color mappings

Rendering Modes

2D Slice Views

• Grayscale: Standard intensity-based display
• Color Mapped: Apply lookup table colors to slices

3D Volume Rendering - Blending Modes

Configure how the volume appears in the 3D view using different blending modes:

Mode	Description
Composite	Standard volume rendering with transfer function control
Maximum projection	Display maximum intensity values along viewing rays (MIP)
Minimum projection	Display minimum intensity values along viewing rays (MinIP)
Average	Display average intensity values along viewing rays
Additive	Additive blending for accumulation effects

info

Isosurface and Average modes are only available when using GPU ray casting.

Interpolation

Select the sampling method for volume rendering:

Mode	Description
Nearest neighbor	Fast, no interpolation between voxels (blocky appearance)
Linear	Smooth interpolation between adjacent voxels (default)

Opacity and Transfer Functions

For volume rendering, define how intensity values map to opacity:

• Scalar Opacity: Control transparency based on voxel intensity
• Gradient Opacity: Enhance edges by increasing opacity at intensity transitions

Shading

Enable lighting effects for improved depth perception. Shading parameters include:

Parameter	Description
Ambient	Base illumination level (0-100%)
Diffuse	Directional light response (0-100%)
Specular	Highlight intensity (0-100%)
Power	Shininess/highlight focus

Shading Presets:

• Ambient
• Dull
• Smooth
• Shiny
• Bright
• Custom

Visibility Controls

Option	Description
Visible	Toggle volume visibility in all views
Visible in 2D	Show/hide in slice views only
Visible in 3D	Show/hide in 3D view only

Workflow

1. Select the volume you want to configure.
2. Open Render Properties from the Image tab.
3. Adjust Window/Level to display the intensity range of interest.
4. Select a color lookup table if needed.
5. Configure 3D rendering mode based on your visualization needs.
6. Adjust opacity settings for volume rendering.
7. Changes apply immediately to the views.

Presets

Save commonly used render configurations as presets for quick application to other volumes:

1. Configure all render properties as desired.
2. Click Save Preset and provide a name.
3. Apply saved presets to other volumes using the preset dropdown.

info

Render properties are saved with the project file and restored when the project is reopened.