SoftPlan has 4 different Reference Points available. Understanding how these work can make your life much easier. Reference Points can be used to align drawings when you Overlay them or Assemble them for 3D. They can also be used as a means for assuring an exact placement when you merge two drawings together.
The four Reference Point types are Reference Circle, Reference Triangle, Reference X, and Reference Square. Any of these can be used but you must use the same type on each drawing you want to overlay, merge, or assemble. If 'Drawing A' uses a Triangle Reference Point and 'Drawing B' uses the Square Reference Point and you perform one of the above mentioned functions then the reference points will have no effect.
The Reference Circle has a special property that the others do not. The Reference Circle will also affect the elevation of your assembled floors. If your lower floor has varying wall heights then when you assemble your floors the lowest point of your second floor will be at the elevation of the tallest wall on the first floor. By using the Reference Circle you can define at what elevation the second floor should be.
This image illustrates a second floor. By using File ⇒ Overlay we can see the first floor below it. But we have a problem. The two floors are not in the same location so they do not line up. By placing the same reference point in the same location on each floor we can align the floors without having to actually move the drawings.
If we view the plan in 3D we can see that the floors are not stacked correctly. Another problem that might not be so noticeable from this angle is that the second floor elevation is not correct. This is because some walls on the first floor are taller than others. As stated earlier, when there are multiple wall heights then the lowest point on the upper floor will be at the same elevation as the highest point on the lower floor.
Let's correct the alignment by using Reference Points. I'm going to use the Reference Triangle first. As you can see in this image the floors are now aligned because I placed the Reference Triangle at the same location on both the lower and upper plans.
But we still have a problem. The second floor does not sit down on the first floor because the first floor has different wall heights. The problem is that even though the Reference Triangle will align the plans to a common location it does not affect the elevation height. So what are we to do?
Let's delete the Reference Triangles and replace them with Reference Circles. Since the Reference Circle also affects floor stacking it will cause the second floor to drop down to the proper elevation.
But wait, the second floor is still raised above the first floor. If the Reference Circle is suppose to give the second floor the proper elevation then why didn't it work? For the Reference Circle to correct the second floor elevation it must be located on a shorter wall in the first floor. When I placed the Reference Circle it was placed on a taller wall. So let's try again.
This time use the Reference Circle and place it at a location on the shorter walls of the first floor.
Now the floors are aligned and because we used the Reference Circle on a lower wall of the first floor the elevations are correct.
If all of your walls are the same height then any of the Reference Points will work equally well for aligning your floors. But if you are using multiple wall heights then you need to use the Reference Circle and make sure it is placed at a location where the walls are shorter on the first floor.
Bill is the owner and maintainer of SoftPlanTuts.com