In this lesson I will draw several closed contours that represent the walls of the ground floor. To begin with, I will zoom in on the appropriate part of the drawing and turn off a few Layers. The easiest way to do this is to use the Layer Off function, so I’ll click on this icon and then select the elements that I don’t need right now. This category includes interior walls, furniture, doors, roofs, a staircase with a railing and a few other small things. Since I have removed the unnecessary elements from the screen in this way, I can press Enter and terminate this function.

As you can see, the walls are currently represented by simple lines, and I need a closed contour to create a 3D model, which can be obtained most easily by using the Boundary function. Before I move on to drawing new elements, I will create another Layer and name it 3D-Walls. After that, instead of the default white, I can choose a red color and activate a new Layer with one stroke. AutoCAD will automatically place it at the top of the list, because the rule that numbers are placed before letters also applies here.

Now I can zoom in on the top left corner of the plan and run the Boundary command. In the box that follows, there is an option that allows me to select the object type, which can be a region or a polygon line. Since my drawing mostly consists of simple lines, I will opt for the second option and immediately move on to the next step. I am now expected to select a point that is inside the future element, so to that end I will click on the Pick Points button and place the cursor between these two lines. If I press the left mouse button after that, a new element will automatically appear on the screen that accurately describes the edges of the future wall. Now all I have to do is press Enter and complete this function. At first glance it looks like nothing happened, but if I use the Regen function and refresh the drawing view, you’ll see that a new element has now appeared in the left corner. It has a closed contour form which means it can easily be turned into a 3D object.

I can create the other contours in the same way, and since the inner point selection button is still active, it is enough to press Enter and simply mark the corresponding points with the mouse. If I then move to another part of the drawing and continue to select, AutoCAD will warn me that it is not able to accurately determine the edges of the future contour. This means that the Boundary function can only handle the elements that are currently on the screen, so I have to press Enter and complete this cycle. Since I’ve moved in the meantime, I can repeat the same process and continue adding new contours.

It seems to him that there will be problems in this part, because the line representing the edge of the wall is not complete. I’m going to run the Boundary function anyway and pick a point inside the wall. As I suspected, a box will appear on the screen in which the program informs me that it is not able to determine the exact shape of the future contour. In that case, I have no choice but to terminate the Boundary function and correct this defect. I will simply delete this shorter segment and then run the Fillet command and connect the remaining lines. If I then go back to the contouring function and select the same point, the whole process will be completed successfully.

The next segment is a bit more complicated because the wall stretches almost the entire length of the inner courtyard. Regardless, the Boundary function will do its job flawlessly so I can go ahead and add a few more new contours right away. Each of them represents an independent poly line, so creating 3D objects shouldn’t be a problem. Unfortunately, the facade wall is currently off-screen, so I need to complete the currently active command, move the view of the entire drawing, and then continue creating new contours. That means I’m just a few mouse clicks and one screen refresh away from finishing this lesson.