VTK RectilinearGrid#

.vtr read + write eager

Summary of the specification#

.vtr is one of the VTK XML serial formats. A <VTKFile type="RectilinearGrid"> root wraps a piece whose extent is declared as six integer indices, and whose geometry is three independent coordinate arrays — one per axis — rather than an explicit point list. Data arrays live in <PointData> and <CellData> and may be stored inline as ASCII, inline as base64, or appended as a single raw block referenced by byte offset, optionally zlib-compressed.

Specification at a glance#

root	<VTKFile type=”RectilinearGrid” version=”1.0” byte_order=”…”>
geometry	<Coordinates> with three <DataArray>, one per axis
extent	WholeExtent / Extent as six integers: x0 x1 y0 y1 z0 z1
storage	format=”ascii” \| “binary” (base64) \| “appended” with offsets
compression	optional vtkZLibDataCompressor header

Read the full VTK RectilinearGrid specification ↗

Reading#

import polyxios as px

mesh = px.read("model.vtr")
mesh.vertices          # (n, 3)
mesh.element_types     # element groups found in the file

Writing#

px.write(mesh, "out.vtr")

This codec takes no format-specific options.

Quirks worth knowing#

The implied point grid is expanded to explicit vertices on read, so a rectilinear file behaves like any other mesh downstream.
Appended and base64 payloads are decoded eagerly — the XML container has no seekable layout for mmap, so lazy=True has no effect.