The
function of this exercise is to show you how to;
·
Import data from another Survey/Contouring Program
·
Form the Model and Contour the job.
·
Import road alignments designed in a CAD package.
·
Use
the alignments to interpolate profiles and sections.
Start
Ezicad and use File New to start a new job called ‘import’.
If you look at the adjacent
screen you will see that I have simply typed in ‘import’ and have not worried
about the ‘cdsdb’ that Ezicad appears with in the first place.
I
have also typed in a job description so I will have a little more information
to identify the job with, and I recommend that you get into this same habit of
always supplying at least a description with each new job you open.
Once
you select Open, the program will display a blank job screen ready for you to
proceed.
You
have been sent a file from your colleague who did the field survey, and in this
case she has told you that she has supplied you with a civilcad ASCII file
called ‘surface1.asc’.
In
real life you might equally have been given an SDRmap coordinate file, or
a MOSS Genio, or a Geocomp file.
What
is important here is to learn the process so that you can later apply it to
particular circumstances, and the process is essentially the same regardless of
the origin of the file you need to import.
The
first step in the process is to import the file called ‘surface1.asc’.
Pull
down the File menu, and select Import.
Use
the pull down File Type option to select a Civilcad ASCII File Ver 4.
Don’t be concerned what this
particular format is as it is largely irrelevant – you need to learn the
process so you can use your own data types later.
Use
the Browse button to look in the \Ezicad_Premium\tutor folder, and you should
see a file named ‘surface1.asc’ appear in the search window.
Pick
this file and then select OK.
Ezicad
will ask if you wish to import all or a range of the points in the file, and
you should make sure All is selected, and then press OK.
You
will see the action bar along the bottom fill in as the points are imported.
Next
Ezicad will inform you that it has found strings in the ASCII file, and ask if
you wish to import them. Select Yes.
Ezicad
will now ask you to provide a string folder to store these strings in.
The
folder name is of no great importance, as long as you use a name that makes
sense, and here, since the strings have originated in the field, I suggest a
folder name of ‘field’.
Once you have supplied the
name, the program will commence importing the strings, and when it is finished
you should see a mass of points appear in the center of the screen.
Use
Zoom Extents to zoom to the full screen view of the job, and you should now see
a screen like that at right.
At
this stage you need to form a contoured model, and while these steps should be
very familiar to you by now, I will repeat them to reinforce your memory.
Pull
down the Contour menu, Select Surface parameters and rest to pick up the
extents of the job. Now change the Major Contour interval to 2 metres, and the
Minor Interval to 0.5.

Pull
down Contour, Select Surface area, and select Extents. Next form the Model.
Calculate
and store the contours and you should see a screen similar to that at left.
There
is obvious work to do in removing long triangles on the left of the job, and
assorted other titivation, but that is of no interest to us here, and we move
on to importing the design layout from the CAD package.
It
is common to be given a CAD drawing which has the design layout that you need,
and you will need to import that information into Ezicad.
Please
NOTE that it is important to try and ‘control’ this information at the CAD
stage if you possibly can, because it can save you hours of subsequent ‘sorting
out’.
It
is usual for the architect or engineer who is doing the overall design to have
a reasonably complicated drawing with all manner of things shown, including underground
utilities, internal walls in buildings, overhead power lines, and fanciful
landscaping, not to mention wonderfully ornate borders and title blocks.
It
is also usual that you are really only interested in bringing a few of these
things into Ezicad.
If
the CAD operator has placed different things on different layers, then it can
make your task simple if you can ask the CAD operator to turn off all the
layers that do not interest you.
Even
better to get the CAD operator to actually ‘extract’ or copy the layers that do
interest you into a separate drawing, and then simply give you that ‘smaller’
drawing to process.
I
should also warn you that because of the way in which CAD packages construct
polylines, it is quite common for you to get double the number of points that
you actually need when the data arrives into Ezicad.
And,
as a final note of caution, if someone suggests that they give you a DXF,
please ask them if you can have the DWG file instead, as it is considerably
smaller in size and therefore quicker to process.
OK,
enough of the warnings and on with the job.
You
will have been supplied with a file called ‘lotdwg.dwg’ which is an Autocad®
drawing file in which one of your colleagues has designed a proposed layout for
a subdivision on the land you have modeled earlier.

Select
the File menu, and then choose Import DWG/DXF.
Use
the Browse option to get to the folder
\tutor, and you should see a file named ‘lotdwg’ presented.
Select
it and open it, and you will now be presented with a screen similar to that
adjacent.
The
first thing you need to do is to actually read through the drawing to determine
what information it contains, so select the “Read” button on the bottom of the
window.
Now
the screen will appear as seen below.

You
will see that a number of layers are listed as being contained in the drawing,
but only the one called ROAD is actually checked to indicate that it will be
imported. The other layers have been
turned off by the CAD operator as I suggested above.
If
the operator has not turned the layers off, and you can determine what ones are
relevant, you have the option of specifying which layers are actually imported
into the Ezicad model. Double click on the check box next to the layer name; to
toggle the displayed value form off to on and vice versa.
Now
that you have something to process, you need to give some more consideration to
the fields at the top of this screen.
It
is a good idea to start the point numbering for these new points at a
‘distinct’ number which is either an even hundred or an even thousand for ease
of manipulation. Here I suggest that you start from 1000, so enter it in the
relevant field.
You
need to enter a string folder to store the strings in, and a number to start
from, and in this case a folder of ‘dwg’ and a number of 1 will suffice.
Note:
future releases will automatically assign strings to folders with the name of
the layer the strings came from, but please enter the folder name to allow them
all to be stored together for the time being.
Press
the Save button and you will find that Ezicad reads through the drawing again,
and this time stores the points and strings into your job.
In
real life where you are likely to received considerably larger drawings that
the one here, please be patient while the program process the file as it can
take a little while.
Once
the screen re-appears, press the F8 key to turn off the triangles, and the F7
key to turn off the contours and you should be able to see the outline of a
cul-de sac.
Now select the Layers icon on
the toolbar, (or use the F10 key) to access the layers screen, and turn off all
layers except ROAD, which is the layer you imported from the drawing.
The
screen should now appear as seen at right, and you can see a clearer picture of
the strings and points you have imported.
If
you look closely at the points, you will see that a number of them appear to be
overwritten, and this is due to the ‘duplicate’ points that are often created
in CAD packages.
Pull down the Options Menu,
select QA Routines and then select Filter Duplicate Coordinates.
The
screen will be similar to that adjacent, and you need to uncheck the box ‘Keep
Points Used in Strings, since all of the offending points in this case are in
strings.
Next
you should check the button titled Delete Higher numbered one, since this is
the most effective method of dealing with CAD induced duplicates.
Press
the OK button and the program will go about its task.
Once
this is completed, you will see that the strings remain in place, but the
‘double’ points have disappeared.
You
can now use these strings to interpolate profiles and sections across the
surface.