# Using Dynamo for Automatic Reconstruction of BIM Elements from Point Clouds
## 4 Results  
The physical characteristics of the Old Lifeguard Station of Fuseta building were analyzed on a case-by-case basis to define the modeling approach used for each element. It was chosen to prioritize automatic and semi-automatic modeling approaches for the most part. The manual modeling approach was used only in cases where there were physical  
Figure 17: Diagram of the solution developed for the floor and roof automation modeling algorithm. Figure 18: (**a**) The algorithm developed with Dynamo for automatic detection and modeling of floor and roof. (**b**) Point cloud used. (**c**) BIM elements created in Revit using the Dynamo algorithm. limitations of the element, a lack of necessary points in the point cloud, or a pre-defined modeling strategy within the BIM workflow. Thus, the final model of the building had elements created with the three types of methods: automatic, semi-automatic, and manual approaches (Figure 19). The building contains two types of structural concrete columns, one type located at the base of the building and the other on the main floor that supports the roof slab. The base and the support columns of the access ramp have rectangular profiles with chamfered corners. The columns on the main floor have a rectangular profile without chamfers. The algorithm developed for the columns can be used for both cases and allows the operator to choose which type of family should be used for the 3D reconstruction. A generic rectangular column was chosen for the main floor columns, and for the octagonal columns, a particular family was created. The building has 68 columns; 45 of them were created automatically with Dynamo script, and 5, located at the base of the access ramp, had to be created manually because they did not have enough points in the point cloud for the algorithm to recognize their shape and reproduce their geometry. Other than these columns, 18 were embedded columns and were not considered because they would need to be manually inserted using external data other than the point cloud. All columns were created as a native BIM element of the Revit software in its structural column category, and in all cases they were made with an automatic method. It was possible to position the element with its proper inclinations, deviations, and rotations. Figure 19: BIM model of the Old Lifeguard Station of Fuseta building created with automatic, semi-automatic, and manual approaches. The building's structural beam system is characterized by having three types of concrete beams of rectangular sections, one type located at the base of the building close to the ground, another type supporting the main floor slab and the access ramp, and a third located inside the building that supports the roof slab. The beams close to the ground, like the base columns, have a rectangular chamfered profile; the main floor support beams also have a rectangular profile but with chamfers only on their lower corners; and the building's internal beams are rectangular without chamfers. Specific families were created for the beams with a chamfer; a standard family of a rectangular profile from Revit was used for the type without a chamfer. In total, 127 beams were modeled, 90 of which were modeled with the automatic approach, 19 with the semi-automatic approach, and another 18 with the manual approach. The same algorithm was used for automatic and semi-automatic modeling; the difference between the approaches occurred in cases where the algorithm could not accurately identify the actual dimension of the beam profile, which was corrected manually afterward. These inaccuracies occurred only in the beams that were partially buried in the ground, which compromised the automatic detection of the dimension of the profiles, but this fact did not affect the identification of the correct position and height of the insertion of the beams.