Primitives

Primitives are geometric shapes used in Volvicon to define regions of interest (ROIs), create geometric references, and assist with analysis. They serve as tools for isolating specific areas of your data and performing geometric operations.

Primitive Types

Volvicon provides the following primitive shapes, accessible from the Measure ribbon tab under Primitives:

Point-Based Primitives

These primitives are defined by a center point and size parameters:

Primitive	Description	Use Case
Point	Single location marker	Seed points, markers
Circle	2D circular region	Circular ROI on slices
Sphere	3D spherical region	Spherical ROI, seed regions
Ellipsoid	3D ellipsoidal region	Non-uniform spherical ROI
Plane	Infinite flat surface	Clipping, cross-sections
Cube	Equal-sided 3D box	Cubic ROI
Cuboid	Rectangular 3D box	Rectangular ROI, cropping

Line-Based Primitives

These primitives are defined by two endpoints:

Primitive	Description	Use Case
Line	Straight segment between two points	Distance reference, profiles
Cylinder	Cylindrical volume along an axis	Tubular structures, bore analysis
Capsule	Cylinder with hemispherical ends	Rounded tubular regions
Tube	Hollow cylinder	Pipe analysis, annular regions
Cone	Conical volume	Tapered structures
Arrow	Directional indicator	Annotations, directions

Curve-Based Primitives

Primitive	Description	Use Case
Spline	Smooth curve through control points	Curved paths, organic shapes

Primitive Tools

The Measure ribbon tab provides these primitive-related tools:

Tool	Description
Primitives	Add geometric primitives to the project
Primitive Fitting	Automatically fit primitives to geometry (surfaces, edges)
Measurement between Primitives	Calculate distances and angles between two primitives

Region of Interest (ROI)

Primitives are commonly used as ROIs to:

• Crop – Limit processing to a specific region
• Isolate – Extract a portion of the data
• Measure – Calculate statistics within the region
• Segment – Apply segmentation tools only inside the ROI
• Clip – Hide parts of 3D renderings

ROI Operations

Operation	Description
Crop to ROI	Create a new volume containing only the ROI region
Mask from ROI	Create a mask matching the primitive shape
Statistics in ROI	Calculate mean, min, max within the region
Clip rendering	Hide geometry outside the ROI in 3D view

Primitive Properties

All primitives have these properties:

Property	Description
Position	Center location (X, Y, Z)
Size/Radius	Dimensions of the shape
Orientation	Rotation angles or axis direction
Color	Display color
Opacity	Transparency level
Visibility	Show or hide
Name	User-defined label

Working with Primitives

Creating Primitives

1. Go to the Measure ribbon tab
2. Click Primitives and select a primitive type
3. Click and drag in a view to place and size
4. Adjust properties in the Properties panel

Primitive Fitting

Use Primitive Fitting to automatically fit primitives to existing geometry:

1. Select a surface or edge
2. Click Primitive Fitting
3. Choose the primitive type to fit
4. The primitive is positioned and sized to match the geometry

Measurement between Primitives

To measure relationships between primitives:

1. Create two primitives
2. Click Measurement between Primitives
3. Select the two primitives
4. View distance, angle, or other geometric relationships

Common Workflows

Task	Primitive	Steps
Crop volume to region	Cuboid	Create cuboid → Crop to ROI
Isolate spherical sample	Sphere	Position sphere → Extract region
Analyze cylindrical bore	Cylinder	Align with bore → Measure diameter
Create cross-section	Plane	Position plane → View slice
Mark reference points	Point	Place points → Use for alignment

Related Topics

• Measurements – Measuring with primitives
• Masks – Creating masks from primitives