3D grid: about
Definition
A 3D grid is a volume support, on which the user can evaluate a spatial quantity.
Use
A 3D grid is used for:
 plotting of scalar spatial quantities as colorshading isovalues
 plotting of scalar spatial quantities as arrows
 exportation of values
Shapes of 3D grids
3D grids can be of the following shapes: cube, rectangular parallelepiped, sphere, cylinder or a part of cylinder.
3D grid and infinite box
The spatial support of the 3D grid type can be extended beyond the bounded study domain.
Mesh
The mesh of a 3D grid is based on a userdefined discretization: computation points are regularly spaced in the volume of the support.
Cube
A 3D grid of the cube type is characterized by a position, a dimension and a discretization.
An example of the definition of a cubeshaped 3D grid is presented below.
Definition of the "Cube" 3D grid  

The position is defined by:


The dimension is defined by an edge length L of the cube 

The discretization are defined by a number of elements along the cube edge 
Parallelepiped
A 3D grid of the parallelepiped type is characterized by a position, dimensions and discretizations.
An example of the definition of a parallelepipedshaped 3D grid is presented below.
Definition of the "Parallelepiped" 3D grid  

The position is defined by:


The dimensions are defined by:


The discretization are defined by a number of elements along the three main axes (X, Y, Z) 
Cylinder
A 3D grid of the cylinder type is characterized by a position, dimensions and discretizations.
An example of the definition of a cylindershaped 3D grid is presented below.
Definition of the "Cylinder" 3D grid  

The position is defined by:


The dimensions are defined by:


The discretization are defined by: 






Part of cylinder
A 3D grid of the type of a part of cylinder is characterized by a position, dimensions and discretizations.
An example of the definition of a 3D grid of a part of cylinder (a part of a full cylinder) is presented below.
Definition of the "Part of Cylinder" 3D grid  

The position is defined by:


The dimensions are defined by:


The discretization are defined by: 






Angle unit of coordinate system  Angle θ 

degree  0< θ  ≤ 360 
radian  0< θ  ≤ 2 π 
Sphere
A 3D grid of the sphere type is characterized by a position, dimensions and discretizations.
An example of the definition of a sphereshaped 3D grid is presented below.
Definition of the "Part of Cylinder" 3D grid  

The position is defined by:


The dimensions are defined by a radius 

The discretization are defined by: 





