The Build tools are a set of tools that help in creating new
objects from existing ones.
Make rights-of-way / pavements / ramp
line : GT_ROWMAKER
GT_ROWMAKER command can be used to create right-of-ways by offsetting a
road center line on both sides by a specified distance. It can be used
with both 2D and 3D polylines, as well as polylines with arcs and Spline objects.
Width of right-of-way: Specify the width of the right-of-way.
Select R-O-W layer: Select the layer into which the newly created
ROWs must be placed.
Draw center from road R-O-W
line : GT_CENTLINE
GT_CENTLINE command is used to create road center lines from
right-of-ways. The user must draw zig-zag lines across the right-of-way
along its entire length. The mid-point of the segment of the zig-zag line
that intersects the right-of-way is taken as the road center line point
and the line joining a series of such center line points forms the road
Digitize Road Center Lines from Rights-Of-Way:
Pick Start point of line: <do so>
First zig-zag point: <do so>
Generate/Jump/Manual/Undo/eXit:<Next zig-zag point>: <pick a point
or Type G, J, M, U or X>
starting the GT_CENTLINE command, you are asked to pick the start point of
the road center line. Pick a point as shown in the illustration above. A
sub-menu appears which provides the following options:
Manual option allows the road centerline points to be manually digitized.
This option should be used when it is easier to specify the road
center-line point by a direct pick rather than by the zig-zag method.
Generate/Jump/Manual/Undo/eXit <Next zig-zag point>:
The default option is to pick the next zig-zag point. In the illustration
above, the zig-zag lines are shown by the red lines. GT_CENTLINE
determines where each zig-zag line exactly intersects the right-of-way and
calculates the mid-point between them as the road center line point.
Generate [G]: The Generate option is used to display the road
centerlines drawn so far.
Jump [J]: The Jump option is used to temporarily suspend the
digitization of a zig-zag point. This is an on/off toggle. This option is
typically used when you want to skip certain areas and would like to move
the zig-zag point to another place to continue the digitizing.
Undo option allows the last digitized centerline point to be undone.
X option exits the GT_CENTLINE command and creates the road centerline
digitized so far.
Offset 3D polylines.
line : GT_3DOFFSET
The GT_3DOFFSET command is used to offset 3d
polylines in the same manner as 2d polylines. 3D polyline can be offset both
horizontally and vertically. This can be a very useful in several civil
engineering design situations that require the offsetted polyline to be elevated
or lowered by a fixed amount relative to the source polyline.
Draw centroidal marks inside closed polylines.
line : GT_CREATECENTROID
command is used to create centroidal marks inside closed polylines, splines and circles.
Layer to create in:
Source: Creates the centroidal marks in the source layer( i.e the layer
in which the closed polylines reside).
Current: Create all the centroidal marks in the current layer
Specify: Choosing this option allows specifying the layer in which the
centroidal marks will be created.
Select: Clicking on Select button pops up the Select Layer dialog
Object to create: Specifies the type of object to create.
ACAD Point: An AutoCAD/BricsCAD point object is created at the centroidal location
of each closed polyline.
Running Text Number: A Text string is created which is incremented by 1
each time for the next polygon being annotated with centroidal marks.
Fixed Text string: A fixed text string value is used for the annotation
of the centroidal mark. The value of this text string is specified in the edit
box provided for it.
Start Number: Specify the start number to be used for the annotation, if
the Running Number Text option was chosen.
Format Width: Specify the required format width. This will prefix Zero
before the running number text such that the string length is atleast equal to
the format width specified.
Fixed Text string value: Specify the value of the fixed text string to
use for annotations.
Text Height: Enter the height for marking the Text string or Running
Ensure that the centroidal point always falls physically inside polygon:
If this option is checked and if the centroidal falls outside the polygon, it
will be moved to a location physically inside the polygon.
The GT_CREATECENTROID command has an option to run without the dialog box
selector. To enable this, you much check the option within the dialog box which says "Hide dialog box and run GT_CREATECENTROID in command-line mode next time". This setting is not saved in registry and revets back to dialog box mode when your CAD is re-started.
Mulitple variable measure command
line : GT_MVMEASURE
GT_MVMEASURE command allows multiple and variable distances to be measured
along lines and polylines.
Cumulative - From beginning of line: Select this option to mark the
user specified distance on the polyline.
Each segment: Select this option to mark the user specified
distance relative to and following the previous segment.
Place blocks at measured points: This option allows you to select a
block from the current drawing which will be placed at the measured point
Break at measured points: This option breaks the polyline at each
of the measured positions.
Align block with object: Check this option to align the block with
the slope of the line at each point.
Place at first and last point also: Checking this option
automatically places a block or point at the first and last vertices of
Factor: Specify the required scale factor for the block
Join nearest ends of lines / polylines.
line : GT_JNE
command is used to join the nearest ends of two selected lines and/or polylines
with a connecting line and optionally join all the three into one single
Select first object: (do so)
Select second object: (do so)
Join all segments together? [ Yes/No ] <Yes>:
Build common edges along closed adjacent polygons
line : GT_EDGEBUILDER
GT_EDGEBUILDER command is a tool useful for building edges along adjacent,
closed polylines. A typical scenario in GIS data preparation or modeling
involves creating intersection-to-intersection edges on a network of
closed polygons adjacent to each other. The GT_EDGEBUILDER command is an
attempt to fulfill this need in an easy way.
Like in every GeoTools command, it is best to start with data that is as
clean and accurate as possible. BEFORE you start this command, it is
essential that all duplicate segments from the selection are removed and
cleaned using the GT_DISTANGWEED command.
Interpolate point elevation from neighboring polylines - manual pick
line : GT_PTINTERMANUAL
GT_PTINTERMANUAL command is useful to assign point elevations by
interpolating the elevations of neighboring polylines.
Interpolate point elevation from neighboring polylines - automatic
line : GT_PTINTERAUTOMATIC
GT_PTINTERAUTOMATIC command is useful to assign point elevations by
interpolating the elevations of neighboring polylines automatically by
scanning specified layers.
Create closed polylines from a mass of networked polylines
line : GT_CCPOLY
The GT_CCPOLY command is used to create closed polylines from a mass of
inter-networked polylines, lines, arcs and circles. It is nothing but an
automated version of the BPOLY command and it applies BPOLY at regular intervals
in X and Y directions along a rectangular grid and creates closed polylines
(resulting from BPOLY) from the adjoining boundary set. The program uses a
parameter called 'Scan Window Size' to determine the BPOLY sampling interval.
Needless to say, the GT_CCPOLY can be quite slow in its operation because it has
no intelligent way to know how many unique closed polylines would be created.
Since the BPOLY sampling is done at each regular interval, the program takes
more time if the sampling interval is smaller and vice versa. Nevertheless, the
program can be useful in many cases. Use it appropriately by specifying a scan
window size that works with optimum speed and accuracy.
At selected points:
Scan Window Size: Enter the amount of search (scan) size
Zoom Window size: Enter the amount of zoom size.
Select Layer for closed polylines : Clicking on this button pops up
the dialog box for selecting the layers of closed polylines
Select Layer for polygon
edges : Clicking on
this button pops up the dialog box for selecting the layers of
Create a mathematical relative contour offset between two polylines
line : GT_CONTOUROFFSET
The GT_CONTOUROFFSET command
can be used to create an offset polyline in between two given contour polylines.
This command will ask the user for two polylines representing two contours and
will create an intermediate "offset" polyline at the correct
interpolated elevation between the two polylines.
The location of vertices for the offset polyline will be determined on the basis
of configurable parameters like 'Offset Percent' (percentage distance between
the two polylines) or an absolute distance from a point on the first polyline
and measured towards a similar point on the second polyline.
The algorithm used to determine the offset polyline positions is not yet perfect
to handle polylines of all geometric shapes. Often, the command may create
offset polylines which are completely unacceptable as an interpolated offset. We
would like you to be aware of these limitations.
To overcome some of these bugs, you may run the command again reversing the
order of pick for the first and second polylines. This may sometimes produce
Alternatively, you can also try to apply either of the two algorithms that the
program uses. If one algorithm does not work for one set of polylines, the other
might work or produce better results.
To determine a match point on the second polyline, the program uses a technique
which is based on proportionally equivalent distance matching between and along
the two polylines.
Algorithm to use:
Method 1: Select this option to use the primary algorithm
Method 2: Select this option to use the alternative algorithm, if the
primary algorithm does not work.
Percentage: If you select this option, the offset polyline will be
created at the specified percentage distance between the first polyline and
Distance: If you select this option, the offset polyline will be created
at the specified distance from the first polyline towards the second polyline.
At Each vertex: The offset polyline created will have only as many
vertices as the first source polyline.
At sampling interval: If you select this option, the first polyline will
be sampled according to this interval and for each of these sampled points, the
corresponding offset polyline points will be generated.
Sampling interval: Enter the distance along the first source polyline to
create sampling points, which will then be used to create offset polyline
Percentage distance from first polyline: Enter the percentage distance
from first polyline at which to create the offset polyline points.
Actual distance from first polyline: Enter the actual distance from first
polyline at which to create the offset polyline points.
Place points at user defined spacing along linear
line : GT_NETNODES
The GT_NETNODES command is used to place nodes (points) along a linear network of
connected lines and/or polylines. This command performs a simple trace through the
entire network and places points in such a way that that no two points are closer to
each other than the specified distance which is measure along the network (and is NOT
the straight line distance) between the two points. Please be aware that the command
expects that the network is topologically correct, cleaned and that the end points of
the lines are EXACTLY touching each other.
interval for placing nodes : Specify the distance at which the
nodes (points) have to marked.
Search window size : Specify the size for the search window
as per the drawing unit.
Select layer to place nodes : Clicking on
this button will pop-up the select layer dialog box for placing the nodes
(points) in required layer.
: Build Tools
Drape a 3D polyline across a set of intersecting linear objects
The GT_DRAPEPOLY command can be used to drape a set
of 3d polylines (source objects) over a set of intersecting linear objects
(target objects). Upon draping, this command creates vertices all along the
source objects (3d polylines) where they intersect the target linear objects.
source objects: (do
so) - allows a filtered selection of 3d polylines only
target objects: (do
so) - allows a filtered selection of linear objects like lines, polylines
(both 2d and 3d), arcs and splines.
GT_DRAPEPOLY runs, there will be new vertices created on the source
polylines at every point where they intersect the target objects. If the
intersecting objects are 3d, their 3d intersection value will be computed
: Build Tools
: GeoTools Build Split larger polygons into smaller ones
The GT_POLYAREASPLIT command is useful for those who want to proportion large closed polygons into smaller closed polygons cut to an exact target area. This is a useful tool in land acquisition and property parcel planning and sub-division activities.
The GT_POLYAREASPLIT command mimics the manual process of trial & error to arrive at the closest area value. You first pick a closed polyline which represents the larger polygon that needs to be splitted. Next, you must provide two two guide lines, one stationary and another that is moved in small increments in a direction that increases the area. The entire process can be interactive or automatic. As soon as target area is reached, the program stops.