Method for detecting correspondence of a built structure with a designed structure

A computer program product, including a non-transitory computer readable medium, having program instructions stored thereon that when operated on a computer, cause the computer to carry out the method steps of:

• receiving an unorganized point cloud (PC) of the built structure, the unorganized PC containing a data set with a plurality of data points, each of which has an RGB value associated therewith;
• receiving an Industry Foundation Classes (IFC) model of the designed structure, the IFC model including an IFC schema file classifying all object types and object characteristics in the IFC model, the object characteristics including a model object RGB value unique to each IFC object's entity type;
• integrating the unorganized PC with the IFC model;
• identifying objects in the unorganized PC by determining the data points in the unorganized PC that correspond to an object in the IFC model, comprising the step of applying a ray casting object recognition technique from a scan origin on defined trajectories;
• and
• in which the ray casting object recognition technique includes the steps of:
• (i) targeting, for each data point, by casting a ray in that direction along a direction vector computed from the scan origin towards that data point;
• (ii) capturing, by the ray travelling through 3D space until it intersects with any object geometry representing the IFC model;
• (iii) defining, by checking an intersection result, whether a hit depth length of the ray after intersection minus the depth length of the ray between its origin and target point is below the maximum tolerance value, epsilon (ε);
• and (iv) storing data points, objects and ray depths within a maximum tolerance value, epsilon (ε);
• and
• generating a semantic point cloud, the semantic point cloud comprising the data points from the unorganized PC, and for those data points in the semantic point cloud that correspond to an object in the IFC model, overwriting the RGB value of the data point with the model object RGB value from the IFC model.

A system for detecting correspondence of a built structure with a designed structure comprising a processor and a memory, the system further comprising:

• means for receiving an unorganized point cloud (PC) of the built structure, the unorganized PC containing a data set with a plurality of data points, each of which has an RGB value associated therewith;
• means for receiving an Industry Foundation Classes (IFC) model of the designed structure, the IFC model including an IFC schema file classifying all object types and object characteristics in the IFC model, the object characteristics including a model object RGB value unique to each IFC object's entity type;
• means for integrating the unorganized PC with the IFC model;
• means for identifying objects in the unorganized PC by determining the data points in the unorganized PC that correspond to an object in the IFC model, comprising means for applying a ray casting object recognition technique from a scan origin on defined trajectories;
• and
• in which the means for applying the ray casting object recognition technique includes:
• (i) means for targeting, for each data point, by casting a ray in that direction along a direction vector computed from the scan origin towards that data point;
• (ii) means for capturing, by the ray travelling through 3D space until it intersects with any object geometry representing the IFC model;
• (iii) means for defining, by checking an intersection result, whether a hit depth length of the ray after intersection minus the depth length of the ray between its origin and target point is below the maximum tolerance value, epsilon (ε);
• and (iv) means for storing data points, objects and ray depths within a maximum tolerance value, epsilon (ε);
• and
• means for generating a semantic point cloud, the semantic point cloud comprising the data points from the unorganized PC, and for those data points in the semantic point cloud that correspond to an object in the IFC model, having the RGB value of the data point overwritten with the model object RGB value from the IFC model.