# Metafor

ULiege - Aerospace & Mechanical Engineering

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doc:user:geometry:user:points

# Points

## Definition

Geometrical Points (e.g. vertices) are created thanks to an object called PointSet of the Geometry using the member function define(). Once created, they are stored in the PointSet. Points are the geometrical entities of the lowest level. They are used to define later Curves.

pt = pointset.define(number, x, y [, z])

with

 number user number (unique among Points and $\ge 1$) x, y, z coordinates of this point ($z=0$ by default)

## Example

Definition of the 4 vertices of a square of length $L=5$. The python variable $L$ is used here to parametrize the positions of the points.

L=5
pointset = geometry.getPointset()

p1 = pointset.define(1, 0, 0)
p2 = pointset.define(2, L, 0)
p3 = pointset.define(3, L, L)
p4 = pointset.define(4, 0, L)

The following command prints the created points as a list:

print pointset

which produces the following output:

PointSet        of size 4 (hash=off)
Point #1 nDB=[1] (pos in DB) p=[0 0 0]
Point #2 nDB=[2] (pos in DB) p=[5 0 0]
Point #3 nDB=[3] (pos in DB) p=[5 5 0]
Point #4 nDB=[4] (pos in DB) p=[0 5 0]  

## Note

Temporary points can be used to define Axes or Trihedra:

pt = Point(1, x, y, z)

Since this Point was not defined using pointset.define(), it will not be found in the PointSet.