AVS-UCD#

.avs read + write eager

Summary of the specification#

AVS Unstructured Cell Data begins with a five-integer counts line: numbers of nodes, cells, node data values, cell data values and model data values. Node records follow — an id and three coordinates each — then one line per cell giving its id, material id, a cell type keyword (tri, quad, tet, hex, prism, pyr, line, pt) and its node ids. Optional data sections at the end declare component counts and labels before the per-node or per-cell values.

Specification at a glance#

counts line	nnodes ncells ndata_node ndata_cell ndata_model
node line	id x y z
cell line	id mat_id type n1 n2 …
cell types	pt line tri quad tet pyr prism hex
data sections	component counts, then labelled value blocks

Read the full AVS-UCD specification ↗

Reading#

import polyxios as px

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

Writing#

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

This codec takes no format-specific options.

Quirks worth knowing#

The per-cell material id is preserved as an element tag, so material groups survive a round trip.
Node and cell data sections are read into named vertex and element attributes.
1-based node ids are remapped to 0-based indices; the originals are kept as vertex tags.