-This paper outlines a two stage approach for digitally recording cultural heritage sites. This approach involves a 3D modeling stage and the integration of the 3D model into a 3D GIS for further management and analysis. The modeling stage is carried out using a new concept; Historic Building Information Modeling (HBIM) which has been developed at the Dublin Institute of Technology [12]. Historic Building Information Modeling is a system for modeling historic structures from laser scan and photogrammetric data using Building Information Modeling (BIM) software. The HBIM process involves a reverse engineering solution whereby parametric objects representing architectural elements are mapped onto laser scan or photogrammetric survey data. A library of parametric architectural objects has been designed from historic manuscripts and architectural pattern books. These parametric objects were built using an embedded scripting language within the BIM software called Geometric Descriptive Language (GDL). These objects are combined and mapped onto the survey data to build the entire model. After the 3D model has been created the next stage involves integrating the 3D model into a 3D GIS for further analysis. The international framework for 3D city modeling, CityGML has been adopted for this purpose. CityGML provides an interoperable framework for modeling 3D geometries, semantics, topology and appearance properties [13]. The aim of this research is to bridge the gap between parametric CAD modeling and 3D GIS while using benefits from both systems to help document and analyze cultural heritage sites.

ABSTRACT:In an extensive review of existing literature a number of observations were made in relation to the current approaches for recording and modelling existing buildings and environments: Data collection and pre-processing techniques are becoming increasingly automated to allow for near real-time data capture and fast processing of this data for later modelling applications. Current BIM software is almost completely focused on new buildings and has very limited tools and pre-defined libraries for modelling existing and historic buildings. The development of reusable parametric library objects for existing and historic buildings supports modelling with high levels of detail while decreasing the modelling time. Mapping these parametric objects to survey data, however, is still a time-consuming task that requires further research. Promising developments have been made towards automatic object recognition and feature extraction from point clouds for as-built BIM. However, results are currently limited to simple and planar features. Further work is required for automatic accurate and reliable reconstruction of complex geometries from point cloud data. Procedural modelling can provide an automated solution for generating 3D geometries but lacks the detail and accuracy required for most asbuilt applications in AEC and heritage fields.

ABSTRACT:In this paper the current findings to date of the Historic Building Information Model (HBIM) of the Four Courts in Dublin are presented. The Historic Building Information Model (HBIM) forms the basis for both structural and conservation analysis to measure the impact of war damage which still impacts on the building. The laser scan survey was carried out in the summer of 2014 of the internal and external structure. After registration and processing of the laser scan survey, the HBIM was created of the damaged section of the building and is presented as two separate workflows in this paper. The first is the model created from historic data, the second a procedural and segmented model developed from laser scan survey of the war damaged drum and dome. From both models structural damage and decay simulations will be developed for documentation and conservation analysis.

ABSTRACT:This paper outlines a new approach for generating digital heritage models from laser scan or photogrammetric data using Historic Building Information Modelling (HBIM). HBIM is a plug-in for Building Information Modelling (BIM) software that uses parametric library objects and procedural modelling techniques to automate the modelling stage. The HBIM process involves a reverse engineering solution whereby parametric interactive objects representing architectural elements are mapped onto laser scan or photogrammetric survey data. A library of parametric architectural objects has been designed from historic manuscripts and architectural pattern books. These parametric objects were built using an embedded programming language within the ArchiCAD BIM software called Geometric Description Language (GDL). Procedural modelling techniques have been implemented with the same language to create a parametric building façade which automatically combines library objects based on architectural rules and proportions. Different configurations of the façade are controlled by user parameter adjustment. The automatically positioned elements of the façade can be subsequently refined using graphical editing while overlaying the model with orthographic imagery. Along with this semi-automatic method for generating façade models, manual plotting of library objects can also be used to generate a BIM model from survey data. After the 3D model has been completed conservation documents such as plans, sections, elevations and 3D views can be automatically generated for conservation projects.

Historic Building Information Modelling (HBIM) is a new approach for modelling historic buildings which develops full Building Information Models (BIMs) from remotely sensed data. HBIM consists of a novel library of reusable parametric objects, based on historic architectural data and a system for mapping theses library objects to survey data. This chapter describes the development of a library of parametric objects for HBIM that can be used to model classical architectural elements. Steps towards automating the HBIM process are also described in this chapter. Using concepts from procedural modelling, a new set of rules and algorithms have been developed to automatically combine HBIM library objects and generate different building arrangements by altering parameters. This is a semi-automatic process where the required building structure and objects are first automatically generated and then refined to match survey data. The use of procedural modelling techniques with HBIM library objects introduces automation and speeds up the slow process of plotting library objects to survey data.