sgio.ensure_node_ids

sgio.ensure_node_ids(mesh) → None

Ensure mesh has node IDs in point_data.

If mesh.point_data does not contain 'node_id' (or it is empty), generates sequential node IDs starting from 1.

This is a Phase 4 utility intended to make node IDs always present so format-specific writers/readers can rely on them.

Parameters:

mesh (SGMesh) – Mesh object to ensure has node IDs.

Raises:

ValueError – If mesh.point_data['node_id'] exists but its length does not match the number of points.