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This tutorial covers how to convert the 2D polylines
to 3D polylines assigning "Z" values to them and displaying the
"Z" values by using GeoTools Polyline
Toolset and Annotation commands.
1. Open the drawing named lesson1.dwg
which is located in your GeoTools Tutorials folder. This folder is
located in the folder where you have installed GeoTools.
2. You should see a drawing (see Image 4-1) of a pipeline layout, represented by
set of 2D-polylines. Make Save As of this drawing in any of your desired
folder.
Image 4-1
3. First we will convert the 2D-polylines to
3D-polylines,
Converting 2D-Pline to
3D Pline
1.Click on the menu GeoTools=>Polyline Toolset 1=> 2D-to-3D. or type GT_CH2D3D at the command
prompt.
Image 4-2
2. This will pop-up the GeoTools Standard
selection dialog box as shown below in (Image 4-3)
Image 4-3

3. Then from the standard selection dialog box (shown above in Image 4-3) you
can select the objects in various ways i.e.
a) You can click
on the button Scan entire drawing. this will scan the entire
drawing for selecting the 2D-polylines.
b) Or you can use Scan selected
objects for selecting the required objects and while selecting you can
also use the Properties of object to select. for example we will
select all the 2D-Polylines which are drawn on layer PIPE
4. So for selecting the polylines drawn on layer Pipe
under Current Selection Values in option Layers
type Pipe* and with crossing polygon select the polylines. In this
way it will ensure that only polylines from "Pipe" layer are
selected.
5. Lastly click on the button Apply
to convert the selected 2D-polylines to 3D-polylines.
After performing the above steps the 2D-polylines are converted to
3D-polylines with Zero "Z" elevation, so our next process will be to
add the "Z" elevation to the 3D-polyline.
Adding the "Z" elevation to the 3D-polyline.
1. Click
on the menu, GeoTools=>Polyline Toolset 2 =>
Express
Pedit. or type GT_XV at the command prompt.
Image 4-7
2. Select the 4th polyline from the top as shown in the above (Image 4-7) and
then => type "Z" at the
command prompt to add
the Z elevation to the vertex. And to move around the vertex type "N"
or "P", and add the following "Z" values, for the
selected polyline at the specified vertices.
i) 292.0 ii) 294.5 iv) 300.0 vi) 305 ix) 312.6 xii) 316.5 xiv) 320.0
3. Repeat the step number 2. for all the polylines.
After performing the above steps "Z" elevation, is assigned to the
3D-polylines at specified vertices (known elevation loactions). But in between vertices still
have "Zero" elevation. We will now populate all the in-between vertices using linear interpolation
method
Ensuring non zero "Z" elevation to
all the vertices
1. Click
on the menu, GeoTools=>Polyline Toolset 1 =>
Assign
Interpolated Z values. or type GT_Pl_Inter at the command
prompt, you will get a dialog box as shown below. (Image 4-5)
Image 4-5
2. To generate output file of interpolation
check the box "Create interpolation output file" and
specify the location of output file by clicking on the button "Output
filename", then click on OK
3. After clicking on OK button
Standard selection dialog box will appear as shown above in (Image 4-3), to
select all polylines click on "Scan entire drawing"
button.
4. Finally click on Apply button this will fill in all the zero
[0.0] elevation vertices with non-zero values based on a linear distance
interpolation between the next non-zero vertex elevation found.
Labeling the "Z"
values at each vertex
1. Click
on the menu, GeoTools=> Annotation =>
or type GT_Vxlabel at the command prompt, you
will get a dialog box as shown below. (Image 4-4)
Image 4-4

2. Do the following settings in vertex labelling dialog box
a) Under Annotate using choose the option "Z (Vertex
Elevation)" ,
b) Under Prefix Options choose Prefix
with X=, Y=, Z=, specify value "1" in text boxes of Horizontal and Vertical
text offset from the vertex.
c) Specify
the required text
height, rotation angle in the respective boxes
d) Click on
the Select button to specify the layer for vertex labeling. The
layer you select will be shown in the Label layer box
e) Once all
the options are set click on OK button
3. Then the standard selection dialog box will appear, click on Scan
Selected Objects button to select the polylines you
want to label the "Z" co-ordinates.
4. Finally click on Apply button to
label the selected polylines with "Z"
co-ordinates as shown below in the (Image 4-6).
Image 4-6
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