MapInfo Pro

MapInfo Monday: Constructing a Building on a Property

  • 1.  MapInfo Monday: Constructing a Building on a Property

    Posted 04-19-2021 05:54
    Edited by Peter Møller 09-19-2022 04:08

    Happy #MapInfoMonday,

    And what a nice morning. Here in Denmark, it seems Spring has arrived again this year - hopefully for good this time.​

    Today I will show you how you can construct a building that needs to lie a given distance from a property boundary and given distance from an existing building. I will use some of the CAD-like tools from MapCAD again for sure.

    The sketch

    First, let's look at the sketch that I created for the new building.

    As you can see the new building is located 4 meters from the eastern boundary. The south-western corner of the building is 7.5 meters from the corner of the existing building. And finally, the size of the new building is 9.25 by 16.95 meters.

    That's all we need to know to be able to construct the building in MapInfo Pro.

    The Layers

    For the job, I have a couple of useful layers.

    I have a table with measurements which basically are lines that I have drawn on top of existing segments to see the length of these. That's the segments from the property boundary and some of the existing buildings.

    I also have a table with the property polygons and a table with the existing buildings. Both layers are vector layers which means I can snap and trace these objects.

    Constructing the new building

    The new building should lie parallel to the eastern property boundary. This also means that the two ends of the building are perpendicular to the property boundary.

    I start by making a copy of the measurement line that follows the eastern property boundary. I select it and use Ctrl+C and Ctrl+V to copy and paste a copy of this line into the measurement layer. I could have used a different layer instead of the measurement layer.

    With this new line selected, I select the Rotate Object (MapCAD) tool from the Transform dropdown on the Spatial tab. My goal is to rotate this line 90 degrees to get a line that is perpendicular to the existing property boundary. I click on the map near the position of the end of the building on the property boundary. The exact position isn't that important. This is the point I want to rotate the line around.

    The dialog Rotation Angle appears and I change the angle to 90 degrees and click on the Left button. The selected line is now rotated 90 degrees to the left as you can see in the image below.

    I click the OK button to accept the new line.

    The next step is to create the right side of the new building. I make another copy of the measurement line following the eastern property boundary.

    With the new line selected, I select the Move Along tool from the Transform dropdown. 

    I specify the direction I want to move the selected line by dragging a line that snaps to the right end of the rotated line and releasing the mouse button when the cursor snaps to the left end of the rotated line.

    In the shown Move along dialog, I change the distance to 4 meters and hit the OK button.

    Below you can see the measurement line after it has been moved 4 meters into the property.

    To create the other side of the new building, I create a copy of the measurement line inside the property and use the Move Along tool again to move it another 9.25 meters into the property. I use the rotated measurement line again to make sure the distance is measured perpendicular to the property boundary.

    Now we need to calculate where the lower-left corner of the new building should be. It should be 7.5 meters from the nearest corner of the existing building. To find that location, I insert a point at the corner of the existing building and use Buffer Objects from the Buffer dropdown to create a 7.5-meter buffer from that corner.

    Here are the settings I used to create the buffer from the corner of the building. I used a smoothness of 60 segments for the full circle. For this type of construction, you might want to consider using an even higher resolution.

    I can now create new nodes on the left side of the building using the buffer I created. The node at the most northern intersection is where the corner of the new building should be.

    I select the measurement line illustrating the left side of the new building and set this as the target object using Ctrl+T. I select the buffer object and use Overlay Nodes onto Target from the Nodes dropdown to add nodes where the buffer object intersects the measurement line.

    I can use the Move Along tool to move the perpendicular measurement line to that intersection. I move the left end of the measurement line to the intersection. Make sure you snap to the left end of the measurement line and to the intersection too.

    I use Overlay Nodes again to create nodes at the intersections of the three measurement lines making up the new building so far. I select all three lines, set them as targets using Ctrl+T, select all three lines again and use Overlay Nodes onto Target to create new nodes at the intersections.

    I then select these measurement lines one at a time, make sure Reshape has been activated (using Ctrl+R for instance) and I then delete the nodes below and to the right, that I don't need anymore.

    The last few steps are to use Move Along to move the southern end of the building 16.95 meters to the north. Remember to make a copy of it first.

    And finally, move the end nodes of the two sides to the ends of the end measurements line to form a rectangle.

    As always with MapInfo Pro, there is mostly a couple of ways to get to your end goal. If you need to be able to draw the new building, you wouldn't have to shorten these lines. You just need to make sure that you have a node at the intersections that you can snap to.

    You can also use the Line Intersection tool from the Modify dropdown to shorten lines at - or extend lines to - another existing line or segment.

    I hope this gave you some ideas on how you can use the features from MapCAD to construct new features in MapInfo Pro.

    Stay tuned for more tips & tricks next week!

    Peter Horsbøll Møller
    Principal Presales Consultant | Distinguished Engineer
    Precisely | Trust in Data