Command ConPoint
Menu: Info > Construct point
Description:
Constructs a point and shows the coordinates. The command refers to the
fundamental point processor that is used whenever a point is to be
constructed. The supported construction methods are
The command doesn't terminate until a point has been constructed.
The x and y coordinates can be entered as text in the Command Line Menu. The
interpretation method of coordinates can be specified via
#menu(Settings):
- Absolute coordinates always refer to the user coordinate
system.
- Relative coordinates refer to the location of the last
constructed point.
The current coordinate interpretation method is shown in the Command
line prompt.
The mouse or any other pointing device can be used to construct points by
digitizing. A digitized point can be interpreted in three different ways.
The Digitize mode can be set via #menu(Settings) or
#menu(Locate):
- Digitize means that the digitized point is used as the
constructed point. This method is only appropriate if the required
accuracy is very low. The digitizing Cursor is shown below.
- Grid means that the digitized point snaps to the nearest
Grid point in the respective window. The Grid can be defined via
SetRectangularGrid.
If the Grid is off or not defined then the constructed point is exactly
the digitized point. The respective Cursor is shown below.
- Pick means refering to the coordinates of existing
geometry. Control points near the cursor are highlighted and can be
picked reliably. The Cursor has the shape of a square. If more than one
Control point are inside the square then any of these points is accepted
without any user intervention.
Any combination of three different types of geometry can be intersected.
- Lines are constructed via
ConLine. The line is not bound by
its end points and has an infinite length.
- Circles are constructed via
ConCircle.
- Components must exist already. They are graphically
identified by picking.
If multiple intersection points exist then the user must intervene by
digitizing a bias point near the requested construction point.
Projects a point (1) onto a
line (2).
The idea of this construction method is to start at an absolute point
and to add a sequence of vectors until the point is constructed. The default
start point is the origin. It is assumed that the last vector was the unit
vector in x direction. This assumption is important because some of the
operations refer to the previous vector.
Whenever a vector is constructed its length is given as a default value
where it can be edited via the keyboard before commiting. For instance, the
vector could be normalized by entering a length of 1 or its length could be
scaled by 0.5.
- From Point: Sets a new absolute point as
start point of the
vector addition. Any previously performed operations are discarded.
- To Point: A vector from the current point to an absolute
point is constructed. Before adding the
vector the user can edit its length.
- Vector: A vector is
constructed. Before adding the vector the user can edit its length.
- Left: Constructs a vector by rotating the previous vector
by 90 degrees. Before adding the vector the user can edit its length.
- Right: Constructs a vector by rotating the previous vector
by -90 degrees. Before adding the vector the user can edit its length.
- Back: Constructs a vector by rotating the previous vector
by 180 degrees. Before adding the vector the user can edit its length.
- Forth: Constructs a vector that corresponds exactly to the
previous vector. Before adding the vector the user can edit its length.
- Done: Terminates the recursive vector addition.
Example:
