VTK Format Boundary

The VTK boundary supports scalar image handoff and surface-oriented output. For scalar image paths, use the same native facade as the other lossless formats:

let image = ritk_io::read_image_native("volume.vtk")?;
ritk_io::write_image_native("volume_copy.vtk", &image)?;

Surface output uses explicit mesh and polydata writer APIs exported by ritk-io, including write_mesh_as_vtk and the OBJ, PLY, STL, VTP, and glTF helpers. A surface writer does not infer image spacing from a raw point list; construct the mesh in the intended physical frame before exporting it.

Direction-aware volume handoff

ritk-snap::LoadedVolume uses [depth, row, column] axes and keeps its direction cosine matrix beside the decoded samples. The VTK boundary converts that contract to a zero-copy [ritk_vtk::VtkImageVolume] in VTK order [x, y, z] = [column, row, depth]:

let volume = ritk_vtk::VtkImageVolume::try_from(&loaded_volume)?;
assert_eq!(volume.dimensions(), [columns, rows, depth]);
let samples = volume.scalars();

The carrier preserves origin, spacing, direction, channel count and x-fastest interleaved samples while sharing the source allocation. Call to_vtk_image_data only at an existing serializer or filter boundary that requires VTK’s owned Vec<f32> attribute arrays; that operation is explicit and retains the direction matrix on the carrier.

Example Summary