“Torino 1911” Project: A Contribution of a Slam-Based Survey to Extensive 3d Heritage Modeling

Abstract

In the framework of the digital documentation of complex environments the advanced Geomatics researches offers integrated solution and multi-sensor strategies for the 3D accurate reconstruction of stratified structures and articulated volumes in the heritage domain. The use of handheld devices for rapid mapping, both image- and range-based, can help the production of suitable easy-to use and easy-navigable 3D model for documentation projects. These types of reality-based modelling could support, with their tailored integrated geometric and radiometric aspects, valorisation and communication projects including virtual reconstructions, interactive navigation settings, immersive reality for dissemination purposes and evoking past places and atmospheres. The aim of this research is localized within the “Torino 1911” project, led by the University of San Diego (California) in cooperation with the PoliTo. The entire project is conceived for multi-scale reconstruction of the real and no longer existing structures in the whole park space of more than 400,000 m<sup>2</sup>, for a virtual and immersive visualization of the Turin 1911 International “Fabulous Exposition” event, settled in the Valentino Park. Particularly, in the presented research, a 3D metric documentation workflow is proposed and validated in order to integrate the potentialities of LiDAR mapping by handheld SLAM-based device, the ZEB REVO Real Time instrument by GeoSLAM (2017 release), instead of TLS consolidated systems. Starting from these kind of models, the crucial aspects of the trajectories performances in the 3D reconstruction and the radiometric content from imaging approaches are considered, specifically by means of compared use of common DSLR cameras and portable sensors.

Using Drones and 3D Modeling to Survey Tibetan Architectural Heritage: A Case Study with the Multi-Door Stupa

“…Future development should include solving the problem of the missing interior model, potentially using a hand-held mobile laser scanning (MLS) system. According to [43], the accuracy and resolution (at the centimeter level) of this approach supports efficient and robust data acquisition given varying light conditions and visitor presence. Once the two models (UAV-derived and MLS-derived) are finely registered, the complete stupa model will open doors to further elaborations such as section drawing (with known thicknesses of walls and floors) and finding the center of gravity for structural analysis purposes.…”

Hybrid 3D Models: When Geomatics Innovations Meet Extensive Built Heritage Complexes

“…In these types of scenarios, many operative solutions are commonly deployed by endorsed workflows, as introduced, to overcome multiscale and multiresolution issues in outdoor and indoor spaces and some innovative mapping solutions have already been tested [2]. Surely, the multisensors approaches should be validated from a partial to a global viewpoint, to optimize the effectiveness of each sensor data contribution to their integration, finalized to overcome their singular applicability limits and that are aimed at making an experimental workflow effective.…”

“…Another type of laser-based sensor is the ZEB Revo Real Time (RT) by GeoSLAM ( Figure 4); contrary to the motionless TLS system, it is a portable MMS working with a Hokuyo UTM-30LX-F scanner technology and using the SLAM algorithm and an Inertial Measurement Unit (IMU) [33]. This type of sensor is promising because of its 'go-anywhere' definition and that it is currently already quite investigated in the literature [2,17,[34][35][36][37][38][39][40][41][42].…”

“…The entire analysis underlines the potentiality of the integration and fusion of different solutions and it is a crucial part of the 'Torino 1911' project whose main purpose is mapping and virtually reconstructing the 1911 Great Exhibition settled in the Valentino Park in Turin (Italy). each of the aforementioned techniques is connected with pro and cons, it is well affirmed that the right way to carry out a correct survey, which could be considered to be an important research issue, is the 'hybridization' of the approach, in the sense of a combination or fusion of data to obtain a complete, usable, and users-driven 3D digital model.Starting from the work that is reported in [2], where the main issues connected to the use of a Simultaneous Localization and Mapping (SLAM)-based system for surveying complex built heritage were discussed, the objective of the research that is presented in the next sections is to extend and evaluate the contribution of the multisensor approach; mostly referring to the connected techniques for carrying out suitable 3D models for the documentation of extensive built heritage complexes. The different techniques that are employed for data acquisition and processing will be discussed and the adopted strategy, with the accompanying advantages and disadvantages, will be addressed to define a good strategy for obtaining a complete 3D digital model.…”

“…Starting from the work that is reported in [2], where the main issues connected to the use of a Simultaneous Localization and Mapping (SLAM)-based system for surveying complex built heritage were discussed, the objective of the research that is presented in the next sections is to extend and evaluate the contribution of the multisensor approach; mostly referring to the connected techniques for carrying out suitable 3D models for the documentation of extensive built heritage complexes. The different techniques that are employed for data acquisition and processing will be discussed and the adopted strategy, with the accompanying advantages and disadvantages, will be addressed to define a good strategy for obtaining a complete 3D digital model.…”