structured quad mesh with transition zone - Computational Science

I wonder which software can be used to generate the mesh like below. Anybody has an idea?

Definition of the extended quadtree transition patterns. From left to

A Level Set Model for Structured Mesh Representation of Fibrous Preforms used in Composites Manufacturing

Computer Graphics Group

Computational study of the mechanical influence of lacunae and perilacunar zones in cortical bone microcracking - ScienceDirect

Meshing Your Geometry: When to Use the Various Element Types

Modeling and simulation of microstructure in metallic systems based on multi-physics approaches

Hybrid structured-unstructured mesh of computation field. (a) Static

Computational Thermal Multi-phase Flow for Metal Additive Manufacturing

Evidence for chiral superconductivity on a silicon surface

Propagating Design Updates to Structured Analysis Meshes - ScienceDirect

JMSE, Free Full-Text

Structured Meshes