Townscaping: Development of Dynamic Virtual City Augmented 3D Sketch Design Tools

Radar sensors are widely used in intelligent transportation systems. The performance of radar sensors in practical setups depends on many factors, such as sensor specifications, choice of locations, height and orientations of sensor installation. Currently, most of these choices are made by a rule of thumb. In many cases, trial and error changes of settings are required and several rounds of on-site measurements and adjustments are incurred, which are both inefficient and costly. To overcome these problems, this paper reports a 3D virtual radar system that can accurately predict and evaluate the performance of actual radar sensors using a standard computer. The proposed system builds upon a 3D virtual model of real world. It allows users to freely enter specifications for radar sensors and the underlying algorithm can efficient calculate and represent graphically in the 3D model by the coverage area of the chose radar sensors at the specified location in the virtual world. Comparison with experimental data obtained using hardware testbeds shows the result obtained by the virtual radar system is accurate.

In recent years virtual environments (VEs) have become more and more popular and widespread due to the requirements of numerous application areas in particular in the 3D city visualization domain. Virtual reality (VR) systems, which make use of tracking technologies and stereoscopic projections of three-dimensional synthetic worlds, support better exploration of complex datasets. However, due to the limited interaction space usually provided by the range of the tracking sensors, users can explore only a portion of the virtual environment (VE). Redirected walking allows users to walk through large-scale immersive virtual environments (IVEs) such as virtual city models, while physically remaining in a reasonably small workspace by intentionally injecting scene motion into the IVE. With redirected walking users are guided on physical paths that may differ from the paths they perceive in the virtual world. The authors have conducted experiments in order to quantify how much humans can unknowingly be redirected. In this chapter they present the results of this study and the implications for virtual locomotion user interfaces that allow users to view arbitrary real world locations, before the users actually travel there in a natural environment.

Abstract. With recent government initiatives for smart cities, 3D virtual city models are in demand for managing and monitoring the urban infrastructure. 3D building models forms an important component of 3D virtual city model. LiDAR remote sensing has revolutionized the way the third dimension can be precisely mapped and proved to be an important source of data for 3D models. The model thus generated should be in an open data format to be used across various applications. CityGML is an open data model framework that enables storage and exchange of 3D models which can be used for diversified applications. The main objective of this research is to develop a methodological workflow to create 3D building models in CityGML standard from airborne LiDAR point cloud. Initially building points were isolated from the airborne LiDAR data using point cloud processing algorithms. 3D building models with levels of detail (LoD1 and LoD2) were generated from the building points in CityGML standard using commercial (ArcGISPro) well as open source packages (3dfier, Citygml4j). Results prove that the models developed using open source packages are comparable to that provided by commercial packages.

Museums and the Web is an annual conference sponsored by Archives and Museum Informatics.The 99 conference provided us with an opportunity to reflect on how museums are being transformed by the Web as well as to understand the challenges that they are being presented with by the demand for parallel virtual programming

BACKGROUND: The employment of 3-dimensional (3D) virtual models of the organs and tumors, obtained from conventional 2-dimensional (2D) imaging (i.e. computed tomography scan and magnetic resonance imaging) have already demonstrated an outstanding potential in urology, especially in renal surgery. OBJECTIVES: The aim of this systematic review is to provide an updated focus on the results obtained from the preoperative employment of 3D virtual imaging reconstructions in nephron sparing oncological surgery. METHODS: A systematic literature search was conducted in April 2022 using Medline (via PubMed), Embase (via Ovid), Scopus, and Web of Science. The search strategy used PICO criteria and article selection was conducted in accordance with the PRISMA guidelines. The risk of bias and the quality of the articles included were assessed. A dedicated data extraction form was used to collect the data of interest. RESULTS: The initial electronic search identified 471 papers, of which 13 ultimately met the inclusion criteria and were included in the review. 11 studies reported outcomes of virtual models, 2 studies focused on printed 3D models. In these studies, the application of 3D models for preoperative planning has been reported to increase the selective clamping rate and reducing the opening of collecting system, blood loss and loss of renal function. CONCLUSIONS: 3D virtual models seem to provide some surgical benefits for preoperative planning especially for complex renal masses. In the future the continuous evolution of this technology may further increase its field of application and its potential clinical benefit.

In order to generate 3D worlds in an automated way it is important to solve the problem of integrating existing 2D and 3D data automatically. We explain some of the issues of this problem in this paper. We also introduce mechanisms for automated generation of integrated 3D geo-data sets, as well as a prototype that implements these. It is necessary to distinguish the different problems and methods for the generation of buildings and other integrated data and the developed algorithms we work on a strategy for the dynamic generation of 3D tour animations through a virtual city and landscape model that is optimized for a specific tour. We introduce components that allow the generation of a virtual 3D-tour through our demonstration region - the city of Heidelberg - by the automated integration of 2D and 3D data sources to a 3D model. The user is presented with an interactive animation of a 3D scene of a dynamically calculated tour through the hybrid 3D model of Heidelberg focusing on the area around the tour.

Study the conversions through 2D conceptual process to 3D materialized processing of automobile design, help the designer to understand more for communication with the CAS modeler. Based on the case of electric vehicle design for Hunan University, in terms of the aesthetic attributes theory and the key feature line extraction method, a questionnaire survey was conducted to study the similarities between the sketch of designer and the CAS models. The results were calculated from 4 different perspectives, which focused on the weight of features in each view, the consistency of expression attributes, the credibility of the expression of design sketch, and the design interpretation of CAS modelers. The results show there is ambiguity in the designer’s sketch, and variability in the 3D modeler’s interpretation. The difference in modeling idea between different modelers is caused by four main reasons. The research found that a certain range of ambiguity in design sketch and variability in 3D materialized processing based on 3D modeling parallelism show a positive effect on the possibility of design solution space. The study of design thinking between different design roles will be able to help design innovation.

The rapid evolution of the metaverse is driving the development of new digital design tools that integrate Computer-Aided Design (CAD) and Building Information Modeling (BIM) technologies. Core technologies such as Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR) are increasingly combined with BIM to enhance collaboration and innovation in design and construction workflows. However, current BIM–VR integration often remains limited to isolated tasks, lacking persistent, multi-user environments that support continuous project collaboration. This study proposes a BIM-based Virtual World (VW) framework that addresses these limitations by creating an immersive, real-time collaborative platform for the Architecture, Engineering, and Construction (AEC) industry. The system enables multi-user access to BIM data through avatars, supports direct interaction with 3D models and associated metadata, and maintains a persistent virtual environment that evolves alongside project development. Key functionalities include interactive design controls, real-time decision-making support, and integrated training capabilities. A prototype was developed using Unreal Engine and supporting technologies to validate the approach. The results demonstrate improved interdisciplinary collaboration, reduced information loss during design iteration, and enhanced stakeholder engagement. This research highlights the potential of BIM-based Virtual Worlds to transform AEC collaboration by fostering an open, scalable ecosystem that bridges immersive environments with data-driven design and construction processes.

Due to the huge difference in the representation of sketches and 3D models, sketch-based 3D model retrieval is a challenging problem in the areas of graphics and computer vision. Some state-of-the-art approaches usually extract features from 2D sketches and produce multiple projection views of 3D models, and then select one view of 3D models to match sketch. It's hard to find “the best view” and views from different perspectives of a 3D model may be completely different. Other methods apply learning features to retrieve 3D models based on 2D sketch. However, sketches are abstract images and are usually drawn subjectively. It is difficult to be learned accurately. To address these problems, we propose cross-domain correspondence method for sketch-based 3D model retrieval based on manifold ranking. Specifically, we first extract learning features of sketches and 3D models by two-parts CNN structures. Subsequently, we generate cross-domain undirected graphs using learning features and semantic labels to create correspondence between sketches and 3D models. Finally, the retrieval results are computed by manifold ranking. Experimental results on SHREC 13 and SHREC 14 datasets show the superior performance in all 7 standard metrics, compared to the state-of-the-art approaches.

In recent virtual reality systems, users can now experience various types of content through precise interaction with virtual world by incorporating HMD’s and interacts with the virtual world by projecting the user actions in real world beyond audiovisual viewing. Recently, virtual reality technology is also actively applied in the field of arts. This paper proposes a novel immersive virtual 3D body painting system which provides various drawing tools and paint effects used in conventional body painting works for producing high-quality works by giving insights through the stages of either concept design or pre-production. We analyzed the drawing effect of airbrush and painting brush through collaboration with body painting experts and provide excellent drawing effect through GPU-based real-time rendering. Our system also provides users with the management functions such as save/load, undo they need to create works in virtual reality.

Development of three-dimensional cardiac models from computed tomography angiography

The use of empirical design aids seems to have decreased over the last two decades. Some influences in this decline have been the emphasis of rigorous theoretical building science techniques, elaborate computer facilities and inexpensive pocket calculators. Unfortunately no design studio or drawing office library can provide a designer in the conceptual stages of his design with the appropriate data to feed into his computer or calculator for the building he has hardly begun to synthesize. Provided he is not using some entirely new construction system, there is probably some empirical design guide that could help enormously during these early formative stages. The writer believes that both students and architects in practice urgently need design aids for all aspects of building science during the conceptual stages of design. Further if architects are to retain a place in the design of buildings and their environment they will have to design more effectively and efficiently particularly in aspects related to energy efficiency of buildings. Having the basic “grammar” of the design sound in the sketch designs goes a long way to an energy efficient cost effective and architecturally satisfying final design. As empirical design aids have been largely discarded they need to be retrieved and often metricated, or in some cases new aids developed. A central “collection point” for such aids might be a useful start for those interested.

An important security aspect of Virtual Worlds (in particular Virtual Worlds oriented towards commercial activities) is controlling participants’ adherence to the social norms (rules of behavior) and making them follow the acceptable interaction patterns. Rules of behavior in the physical world are usually enforced through a post factum punishment, while in computer-controlled environments like Virtual Worlds we can simply block the actions that are inconsistent with the rules and eliminate rule violations as such. In order to facilitate enforcing the rules in such automatic manner and allow for frequent rule changes, the rules have to be expressed in a formal way, so that the software can detect both the rules and the actions that can potentially violate them. In this chapter the authors introduce the concept of Virtual Institutions that are Virtual Worlds with normative regulation of interactions. For development of such systems the authors employ the Virtual Institutions Methodology that separates the development of Normative Virtual Worlds into two independent phases: formal specification of the institutional rules and design of the 3D interaction environment. The methodology is supplied with a set of graphical tools that support the development process on every level, from specification to deployment. The resulting system is capable of enforcing the social norms on the Virtual Worlds’ participants and ensuring the validity of their interactions.

A declarative approach to procedural modeling of virtual worlds

Background/Objectives: The possibilities of endovascular and minimally invasive treatment of visceral and renal artery aneurysms require precise procedure planning. Accurate visualization of vascular pathologies is crucial in this regard. Expanding diagnostic imaging with real 3D models is one of these methods. The objective of our study was to evaluate the utility of 3D printing and virtual 3D models in visualizing visceral and renal artery aneurysms. Methods: A group of 30 patients with true aneurysms of the visceral and renal arteries was selected based on computed tomography angiography (CTA). Aneurysm morphology, diameters, arterial diameters, and anatomical vessel variants were analyzed. Imaging data were processed and 3D-printed using Fused Filament Fabrication (FFF) technology. The resulting 3D models were measured, and dimensional deviations were compared to radiological images. Results: The cohort included 51 aneurysms across arteries supplying abdominal organs, with splenic artery aneurysms (49%) and renal artery aneurysms (25.5%) predominating. Half of the patient group had multiple aneurysms, and 36.7% exhibited anatomical arterial variants. Forty-three 3D models of visceral and renal artery aneurysms were generated, accurately depicting isolated vascular pathologies and the course of visceral arteries in regions of interest. Measurement analysis confirmed that the 3D-printed models showed a mean dimensional deviation of 0.24 mm compared to radiological images. Conclusions: 3D-printed and virtual models enhance the analysis of vascular pathologies, significantly improving the assessment of pathological changes and visualization of anatomical details, especially in hilar aneurysms and aneurysm branches.