# 3D grid: definition (structure)

## Definition

A 3D grid is defined by:

- a name (and a comment)
- a type
- a coordinate system for definition
- an origin (in a coordinate system for definition)
- specific characteristics belonging to a type
- a coordinate system for definition
- attributes of color and visibility

## Name

The name to identify the 3D grid is set by the user during the creation of this one.

A comment (optional) can be added to the name.

## Type of 3D grids

The different types of 3D grids and the characteristics useful for their description are presented in the table below.

Type | Characteristics | |
---|---|---|

All types | 3D grid origin coordinates | coordinate system for definition |

Type | Characteristics | ||
---|---|---|---|

Cube |
length of the cube edge number of elements along the length |
||

Parallelepiped |
dimension along positive X dimension along negative X number of elements along X |
dimension along positive Y dimension along negative Y number of elements along Y |
dimension along positive Z dimension along negative Z number of elements along Z |

Cylinder |
radius number of elements along the radius |
number of elements along θ |
dimension along positive Z dimension along negative Z number of elements along Z |

Part of cylinder |
internal radius external radius number of elements along the radius |
minimal θ maximal θ number of elements along θ |
minimal φ maximal φ number of elements along φ |

Sphere |
radius number of elements along the radius |
number of elements along θ | number of elements along φ |

## Length and angle units

Length and angle units are those associated with the coordinate system.