This chapter introduces PHIGURE functions which allow configuration of vectors visualization from:
Three types of criterias can be defined for visualization of vectors field :
Selection criteria :
This criteria allows selection of vectors inside a given volume (or surface for 2D). This criteria is used to improve legibility of very dense vector fields.
In 2D, vectors which origin point is in a given rectangle or which the distance from this point to a specific line is lower than d may be selected.
In 3D, vectors which origin point is in a given parallelepiped or which the distance from this point to a specific plane is lower than d may be selected.
Elimination criteria :
After selecting vectors with previous criteria, some of them may be unselected as follows:
An attribute to avoid overlapping of vectors can be set. This attribute checks a selected vector relating to bounding box of its neighbours.
Representation criteria :
This criteria allows definition of appearence of vectors. Color, length, ending point and shape of the vector can be set.
The color may be :
- constant,
- relating to modulus (define the same way as for contouring colors : a list of values is associated to a list of colors),
- given by a user's function which returns a color index,
- given by a user's function which returns a generalized color.
The length may be:
- constant,
- relating to modulus,
- relating to a maximum modulus (this allows a maximum length to be used),
- given by a user's function.
The size of the ending part may be:
- constant,
- relating to modulus,
- given by a user's function.
The different shapes are :
- a line,
- a line with a ending chevron,
- a line with a ending triangle,
- a line with a ending cone,
- a cylinder,
- a cylinder with a ending cone.
Following functions apply for vectors field :