Scan to BIM processes: Heritage accuracy versus BIM semantic

The contemporary process that leads digital surveying of Cultural Heritage to the creation of informed models in a BIM environment follows paths that are now codified for most; however, processes to improve the workflows both in terms of accuracy of results and speed of process still arise. The main cause lies in the lack of interoperability between modelling software NURBS oriented if related to parametric BIM-oriented software. The possibilities of interfacing one with the other have grown exponentially. On one side BIM oriented software look for more accuracy in defining shape objects even if complex or irregular; on the other NURBS modellers look for solving lack of information, necessary for any informed model. Our research question grows in this area and concerns three ways of reconstructing a Neo-Gothic tower to be imported into a parametric modeler for its BIM definition from an accurate point cloud. Workflows are compared to define accuracy, information addable, speed of creation.