Intersection (of non-intersecting linesegments)

You first
have to select two line segments. The tool will always lets
you select two segments. If you select a third one, it
deletes the first segment selection. Please bear in mind that
you have appropriate snapping settings values. You can select
segments either from lines or polygons.

You can
now create an intersection point that will be drawn in
a memory layer. It will create also a line that joins the two
points furthest away with the intersection point.

Arc
Intersection

This tool
lets you calculate an arc intersection from two distances to
two points. You have to select two points. If you select a
third one, the first selection will be canceled. Please bear
in mind that you have appropriate snapping settings values
and the "on the fly" crs transformation should not be
enabled.

When you
have selected two points you can calculate the arc
intersection by entering the distance (in meters) to the two
selected points. The intersection point(s) will be drawn in a
memory layer.

Orthogonal Line

This one
is for creating a orthogonal line (and the intersection
point) from a point to a linesegment. You first have to
select a vertex (which has to be in the current layer) and
then the segment from a background layer. The selector will
toggle between vertex and segment selections. Please bear in
mind that you have appropriate snapping settings

When you
have selected a vertex and a segment you can create the
orthogonal line and the intersection point. These two objects
will be drawn in a memory layer.

Rectangular Points

This
function lets draw points from orthogonal measurements to a
base line. You first have to select the line segment.

If you
selected the base line you can simply enter the abscissa (x)
and the ordinate (y). The origin is always the left point of
base line. But you can invert the origin by checking the
checkbox.

Orthogonal Traverse

With this
function you can draw/calculate an orthogonal traverse
between two points which you have to select first.

After
selecting the two points you can calculate the orthogonal
traverse by entering the distances you measured in one line,
e.g. "3.5 -2.46 -12.33 4.5". This describes an orthogonal
traverse with four distances. If you want to turn left you
have to use negative values.

Show Azimuth

With this
function you can calculate the azimuth
between two points which you have to select first.

After
selecting the two points you can calculate the azimuth just by
pushing the button.

Rotate Feature

This function is
for rotating features. You first have to select the feature you want to rotate
and a vertex which will be the centre of rotation. The vertex does not have
to be on the current layer.

After
selecting the feature and the vertex you can enter the angle of
rotation (in degrees).

Parallel Line

With this function you can create parallel lines. First
you have to select a single line segment.

After
selecting the line segment you can either create a parallel line by entering a fixed length or selecting a vertex point.

Circular Arc

This function creates a
segmentized circular arc. You first have to select three points which will define the circular arc;
the starting point, one point on the circular arc and the end point.

After
selecting the three points you can create the segmentized circular arc. You can choose the
method of the segmentation (pitch or angle) and the tolerance in *CadTool - Settings.*

Modify Circular Arc

You can modify the circular arc you created with the
function above. This tool is only available if there is a linestring layer in editing mode. You can either move one of the arc points - which will change the diameter of the circular arc - or
move the starting/end point. The latter method will define the circular arc with the moving point, the mean arc point and the
other starting/end point.

Circular Arc Digitizing

This function is only available if there is a polygon or a linestring layer in editing mode otherwise
the button is greyed out. You have to hold the ctrl key pressed when adding the three arc points (starting point, arc points, end point).
After adding the third one it will draw the circular arc.
There will no attribute window pop up.

Spline Digitizing

This function is only available if there is a polygon or a linestring layer in editing mode. Digitized points are interpolated using Hermite spline with optional *tightness*. The spline is converted to linestring using *tolerance*. Both *tightness* and tolerance may be changed in settings.

Orthogonal Digitizing

This function is only available if there is a polygon or a linestring layer in editing mode otherwise
the button is greyed out. You have to press the ctrl key to draw lines or polygons with square angles.
To close a polygon you have 2 alternatives:

- You can release the ctrl key before closing the polygon with a right mouse click. You have to draw by eye when you want a square angle.
- When you have the ctrl key pressed when closing the polygon, the first point of the polygon will be moved till the last angle is square.

Cad
Console

The cad
console supports some commands:

- ortho
*on/off*: Toggles ortho mode on and off so you don't need to push the ctrl-button all the time. - ortho
*abscissa ordinate*: Adds an orthogonal vertex point with abscissa = abscissa and ordinate = ordinate. - polar
*angle distance*: Adds a polar vertex point with angle = angle and distance = distance. The angle is always relative to the last segment. - length
*length/off*: Sets the digitizer to a restricted digitizing length for the following segments. - close line: Close the digitized line.
- close poly: Close the digitized polygon.
- exit: Exits the cad console.