# Build a model of blocks¶

## What is a model of blocks ?¶

A block (or a hexahedron) is a volume defined by:
• 8 vertices

• 12 edges

A model of blocks is a set of blocks.

And for each quadrangle of a model of blocks, this quadrangle is:
• or a free face

• or a face shared between 2 blocks

## How to find a model of blocks ?¶

In this version of HEXABLOCK component, the user must find himself the model of blocks that is adapted for his geometry.

## How to create a model of blocks ?¶

When the user find the model of blocks necessary for his geometry to be meshed with hexahedra, HEXABLOCK component has a lot of tool to build this model of blocks:

• basic functions:
• create one hexahedron

• create a hexahedra with 2, 3, 4 or 5 quadrangles

• remove hexahedra

• grid building:
• cartesian grid

• cylindrical grid

• spherical grid

• predefined model of blocks:
• for cylinder

• for pipe

• for two intersected cylinders

• for two intersected pipes

• for hemisphere

• for ring

• powerfull functions:

• make hexahedra by revolution of quadrangles

• cut an edge to slice hexahedra

• replace an hexadron by a pattern

• by transformation:
• translation

• rotation

• scale

• by symetry:
• with a point

• with a line

• with a plane

• by merging:
• of two vertices

• of two edges

• by disconnection:
• of two vertices

• of two edges

## Example of simple model of blocks¶

An exemple of a model with 12 blocks