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Import

The Import page allows you to add new data into an existing project. Unlike creating a new project, import operations are additive—existing project content remains available, enabling you to combine datasets for comparative analysis, multi-modality studies, or progressive workflows.

Import vs. New Project​

ActionBehavior
NewClears the current project and creates a fresh project from imported data
ImportAdds data to the current project alongside existing content

Use Import when you need to:

  • Combine multiple scans or datasets in a single project
  • Add reference surfaces or meshes to volumetric data
  • Merge data from another Volvicon project
  • Load additional data during an ongoing analysis

Available Import Types​

Import TypeDescription
3D ImagesVolume formats (MHD, NIfTI) with embedded metadata
3D Raw ImageRaw voxel data requiring manual parameter specification
Image StackOrdered 2D image sequences (BMP, JPG, PNG, TIF)
DICOM ImagesMedical imaging series with DICOM metadata
3D Images as MasksImport volume files directly as mask objects
Surface CAD/STL ModelsTriangle mesh and CAD geometry (IGES, STEP, STL, PLY)
Volume Mesh ModelsTetrahedral/hexahedral meshes for simulation
Another Volvicon ProjectMerge content from a second project file
Recent FilesQuick access to recently imported data files

Importing 3D Images​

Add structured volume files with embedded spacing and orientation metadata.

Workflow​

  1. Navigate to File → Import
  2. Select 3D Images from the left panel
  3. Click the large icon to open the file browser
  4. Select one or more volume files
  5. The data imports and appears in the Object Browser

Supported Formats​

  • MetaImage (MHD/MHA)
  • NIfTI (.nii, .nii.gz)
  • NRRD

Geometry Matching​

When importing volumes into a project with existing data, Volvicon compares dimensions, spacing, and origin to ensure spatial consistency.

Import Behavior

If geometry matches (within configured tolerance):

  • Import proceeds automatically

If geometry differs:

  • Import is blocked by default with a detailed error message
  • Enable Allow import of images with mismatched geometry in Preferences → Import to proceed
  • Enable Resample mismatched images to automatically align data with the active volume

See Preferences → Import Settings for geometry comparison and resampling configuration.

Importing 3D Raw Images​

Add raw voxel data that lacks embedded metadata.

Workflow​

  1. Navigate to File → Import → 3D Raw Image
  2. Click the large icon to open the Raw Image Import dialog
  3. Select the raw data file
  4. Configure parameters:
ParameterDescription
Dimensions (X, Y, Z)Number of voxels in each direction
Voxel Spacing (mm)Physical size of each voxel
Origin (mm)Position of the volume origin in world coordinates
Data TypeSigned/Unsigned 8/16/32-bit, Float32, Double64
EndiannessLittle or Big endian byte order
ComponentsNumber of components per voxel (1-3)
Header SizeBytes to skip at the beginning of the file
Use CompressionEnable for compressed raw files (ZRAW)
  1. Apply axis or intensity inversion if needed
  2. Click OK to import
warning

Verify that the specified dimensions match your file size. The dialog displays expected vs. actual byte counts to help identify configuration errors.

Importing Image Stacks​

Assemble a 3D volume from ordered 2D image sequences.

Workflow​

  1. Navigate to File → Import → Image Stack
  2. Click the large icon to open the Image Stack Import dialog
  3. Add images using:
    • Select Files: Individual file selection
    • Select Directory: Load all images from a folder
    • Drag and drop files directly into the dialog
  4. Arrange slice order:
    • Use Move Up/Down to adjust individual file positions
    • Use Reverse Order to flip the entire sequence
  5. Configure spacing:
    • Voxel Spacing X/Y/Z (mm)
    • Origin X/Y/Z (mm)
  6. Enable Show file preview to verify correct ordering
  7. Apply transforms if needed (Invert X/Y/Z Axis, Invert Intensity)
  8. Click OK to import

Supported Image Formats​

  • BMP, JPG/JPEG, PNG, TIF/TIFF
tip

Name image files with consistent numbering (e.g., slice_001.tif, slice_002.tif) to ensure correct automatic ordering when loading from a directory.

Importing DICOM Images​

Add medical imaging data with full DICOM metadata support.

Workflow​

  1. Navigate to File → Import → DICOM Images
  2. Click the large icon to open the DICOM Import dialog
  3. Browse to the directory containing DICOM files
  4. Click Load to scan for DICOM series
  5. Select the series to import from the table
  6. Configure options (anonymization, window/level)
  7. Click Open to import

For detailed DICOM import guidance, see DICOM Import.

Importing 3D Images as Masks​

Import volume files directly as mask objects instead of image volumes. This is useful when you have pre-segmented data or label maps from external sources.

Workflow​

  1. Navigate to File → Import → 3D Images as Masks
  2. Select the volume file containing mask/label data
  3. The data imports as a mask object in the project

Geometry Matching for Masks​

Mask imports follow the same geometry checking as volume imports. When importing masks with different geometry:

  • Nearest neighbor interpolation is used by default to preserve label integrity
  • Configure tolerance and resampling options in Preferences → Import Settings
Label Preservation

When resampling masks, use Nearest interpolation to prevent fractional label values that would corrupt segmentation data. This is the default setting.

Importing Surface Models​

Add triangle mesh geometry from CAD or 3D scanning sources.

Workflow​

  1. Navigate to File → Import → Surface CAD/STL Models
  2. Click the large icon to open the file browser
  3. Select one or more surface files
  4. The surfaces import and appear in the Object Browser

Supported Formats​

  • STL (ASCII and binary)
  • PLY
  • OBJ
  • IGES
  • STEP/STP

CAD Import Configuration​

For CAD formats (STEP, IGES), import behavior is controlled by preferences:

OptionDescriptionConfigure In
Geometry handlingPreserve non-manifold features, fix defectsPreferences → Import
Tessellation qualityLinear and angular deflection valuesPreferences → Import
Solid constructionBoolean operations, intersection handlingPreferences → Import
Multi-part behaviorMerge parts or import separatelyPreferences → Import

See Preferences → Surface and CAD File Import Options for detailed configuration.

Tessellation Quality

Lower deflection values produce higher quality surfaces but increase triangle count and processing time. Adjust in Preferences → Import based on your accuracy requirements.

Importing Volume Meshes​

Add tetrahedral or hexahedral meshes for simulation workflows.

Workflow​

  1. Navigate to File → Import → Volume Mesh Models
  2. Select the mesh file
  3. The mesh imports and appears in the Object Browser

Importing Another Volvicon Project​

Merge content from a separate Volvicon project into the current project.

Workflow​

  1. Navigate to File → Import → Another Volvicon Project
  2. Select the source project file
  3. All objects from the source project import into the current project
note

Imported objects retain their original names. Rename objects after import if naming conflicts occur.

Post-Import Considerations​

After importing data:

  1. Verify alignment: For multi-dataset projects, confirm data is properly registered using orthogonal views
  2. Check spacing consistency: Ensure voxel spacing matches across datasets for accurate measurements
  3. Rename objects: Assign meaningful names to imported objects for project organization
  4. Save the project: Commit imported data to the project file
tip

Use Properties to monitor memory usage when importing multiple large datasets. Close unnecessary objects or reduce resolution if memory becomes constrained. Symptom: Imported volume or mask does not align with existing project data in orthogonal views.

Cause: Geometry mismatch (different origin, spacing, or orientation).

Solution:

  1. Check the detailed error message for specific geometry differences
  2. Navigate to Preferences → Import tab
  3. Enable Allow import of images with mismatched geometry
  4. Enable Resample mismatched images to match the project's active volume
  5. Verify interpolation method is appropriate for your data type
  6. Re-import the data

Import Blocked: Geometry Mismatch​

Symptom: Error message displays dimension, spacing, or origin differences.

Cause: Imported image geometry differs from the active volume beyond configured tolerance.

Solution:

Option 1 - Adjust tolerance (if differences are small):

  1. Open Preferences → Import
  2. Decrease Spacing comparison precision or Origin comparison precision
  3. Retry import

Option 2 - Allow and resample:

  1. Open Preferences → Import
  2. Enable Allow import of images with mismatched geometry
  3. Enable Resample mismatched images
  4. Retry import

Option 3 - Prepare data externally:

  • Use external tools to resample data to match project geometry before import

Troubleshooting​

Imported Data Appears Misaligned​

  • Verify coordinate systems and origins are consistent across datasets
  • Check that spacing values are correct
  • Use registration tools to align data if needed

File Format Not Recognized​

  • Verify the file has a supported extension
  • Check that the file is not corrupted
  • For raw data, ensure you're using the correct import type

Memory Errors During Import​

  • Close other applications to free system memory
  • Import fewer datasets at a time
  • Consider importing at reduced resolution if supported