Near Real-Time Semantic View Analysis of 3D City Models in Web Browser

Billen

2022

Transactions in GIS

Twinning elements of reality gains a growing interest in support of decision‐making, learning, and simulations: a single and shared model should provide a unique integrative basis for managing assets of any replica of the real world. From a technical viewpoint, sharing and opening information requires both an exchange format and a high degree of freedom and flexibility. It should allow an important number of users to manage this information, to modify it, etc. Storing and manipulating spatial information concerning the urban built context currently focuses on ensuring consistency thanks to relational databases and predefined schemas. Following a paradigm shift from a relational database to a NoSQL database, a schema validation middleware is proposed to improve the flexibility of storage by conceding a share of its consistency. The flexibility improvements thus provide users a common basis that is able to evolve all along the lifecycle of their models and applications as required for twinning things. It allows users and their applications to take advantage of new storage features such as common: versioning, partitioning, prioritization, applications profiles, etc. The middleware and their new capabilities are illustrated thanks to the CityJSON encoding and its simplified schema for a document‐oriented database.

Section: Related Workmentioning

confidence: 99%

From consistency to flexibility: Handling spatial information schema thanks to a middleware in a 3D city modeling context

Billen

2022

Transactions in GIS

“…Its improved support of levels of detail and metadata make it a good substitute for CityGML (Nys, Poux, & Billen, 2020). However, its usage is still limited to specific applications and data encoding (Kumar, Ledoux, & Stoter, 2018; Nys, Billen, & Poux, 2020; Virtanen et al., 2021). Besides, the new support of 3D models in QGIS should improve its usability thanks to the development of a CityJSON plugin (Vitalis, Arroyo Ohori, & Stoter, 2020).…”

Section: Related Workmentioning

confidence: 99%

From consistency to flexibility: A simplified database schema for the management of CityJSON 3D city models

Billen

2021

Transactions in GIS

The use of 3D city models is now common practice; many large cities have their own digital model. Resilient and sustainable management of these models is necessary in many cases, where an application could evolve over its life cycle. The complexity of generic modelling standardization is often a limitation for a light and user-friendly usage and further developments. This paper aims to propose an alternative providing a simplified database schema implemented in a document-oriented storage. Thanks to the use of the NoSQL store, the focus is on flexibility of the data schemas and thus its clarification. In order to aim attention at the compactness in web development, CityJSON has been chosen for the encoding of the 3D city models. Finally, a full-stack application (persistent storage, consistent edition and visualization of 3D city models) has been developed to handle the simplified schema and illustrates its capabilities in two practical use cases.

“…Recently, the new CityJSON facilitates the evolution of advance decision-making processes. For instance, its lightness and ease to maintain are demonstrated in flood simulations and complex semantic view analysis (Kumar et al, 2018;Virtanen et al, 2021). Still, its core module (v1.0.1) has not been much extended for now, with one exception on topological representation (Stelios Vitalis et al, 2019).…”

Section: Related Workmentioning

confidence: 99%

An Extension of Cityjson to Support Point Clouds

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

Kharroubi

Poux

et al. 2021

Abstract. The combination between dense point clouds and 3D vector objects permits new cartographic representation of urban information. This paper proposes an extension for the CityJSON encoding to support point clouds. Following the 3.0 CityGML specifications, attributes and features are added to the core module of v1.0.1 CityJSON. Two solutions are proposed: inline complex geometries and external link to a remote file. The extended schema can be illustrated in four scenarios: detailed features visualization, fall-back solution in features reconstruction processes, simulating urban climate represented as vector fields, and true-to-life representation solution for complex elements such as solitary vegetation objects. It permits 3D city modelers to handle points clouds in a native way reducing files size and avoiding redundancy. All developments and documentation are available open-source.