Level of expertise required for this Chapter: Intermediate; specifically for LUPMIS @ TCPD
Following functions are available under Drawing > Lines to draw lines:
The advantage of drawing lines with 'Drawing Tools' is that you can define a line in precise terms, for example observed by surveyors in the field. The line starts from a 'start point', which is entered either
As point in Map Maker (‘digitizing a point/symbol’), or
From a point DRA file (previously digitized point), or
From UTM x and y coordinates, entered as numbers.
You then enter the distance / bearing values or the UTM x / y values of each point, which defines the line. But don't mix distance/bearing with x/y. You can define upto 10 points. If you need more entry points, contact TCPD / LUPMIS-HQ.
Define start point > Enter all legs (with distance in meters and bearing, or in UTM with x and y) > Execute
Display of the result, with links to Internet map display:
On Internet OpenStreetMap the points look like this:
All entered distance / bearings / UTM values are listed in a box in the middle of the form and then again after processing.
You can also create multiple identical line in a similar way. They will be located to the right (E, ‘number of lines in the row’) and above (N, ‘number of rows’) of the original line. In addition, you enter the distances to the right and up.
In the sample below, 5 copies to the right and 4 copies up were specified. Be aware, that it produces an entire grid of the original feature and all copies have the same distance and bearing values, as you originally entered.
b) Continue line
A line can ‘continue’ in a given angle to the last ‘leg’. The angle, direction and length of the continuation line have to be entered.
Sample below shows a continuation of the line (in red) in a relative angle of 135° in anti-clockwise direction from the original line.
You can define an 'offset', if you want to start the 'continuation line' before the endpoint of the original line (circle 2 below).
c) Continue line to North
You can also 'continue' a line with a defined angle against North (option 'Continue line (N)'):
This is the less powerful, but easier version of the previous function 'Continue line'. If you want to set a 'splay', you best use this function (with 3 points: 1 at the corner, 2 and 3 to indicate the direction of the sides of the parcel, and the offset value, i.e. the cutting distance from the corner).
After you have defined the 'splay line', have the layer with the parcel in the live layer (not this splay line!) and Select the parcel to be cut > Edit > Show Selection Manager > Selection Manager window: Actions > Basic operations > Cut with file > Cutter file > Select this splay line file > OK.
There is a similar function, which produces a 'curved' (or round) splay line under ' Arcs'.
e) 90 deg angle
If you want to draw a right angle (90°) in an easy way, you can use this tool. You specify the reference line with 2 points: Number 1 anywhere on the line, number 2 where the right angle should be placed. You also define the length of the new line.
f) Center line
If you have two lines of similar (not necessarily same) length, you can have a center line between the two original lines.
The two lines should be in two separate DRA files.
A tangent is the straight line, which 'touches' an arc (or circle) at a given point. It always has a right angle to the radius at the given point.
All you have to do, is to enter 3 points, which define the arc (or circle). The 2nd point is the point, through which the tangent runs. You also specify the length (to each direction) of the tangent line.
h) Parallel by Distance
If you need parallels to a line in a defined distance from this line, you use this tools. You define the original line with 2 points anywhere on the line, and the distance of the new parallel(s) to the original line.
As an option, you can select, if you want parallels on both sides, or only one parallel on one side.
i) Parallel Through Point
This is similar to the tool 'Parallel' above, but you don't enter the distance to the original line in meters, but a point, through which the new parallel should run through.
j) Perpendicular Bisector
A bisecting line cuts half-way through a line between 2 points. You enter the 2 points, between which the bisector should pass, and the length of the bisecting lines on each side (to point 3 and 4, see sample below).
k) Angle Bisector
An angle bisector is the angle, which cuts half through an existing angle. You define 3 points: Number 1 is the intersection point (centre of the angle), the other two points indicate the angle (direction only).
You also define, how long the bisecting line should be.