Making the Third Dimension (3D) Explicit in Hedonic Price Modelling: A Case Study of Xi’an, China

Recent rapid population growth and increasing urbanisation have led to fast vertical developments in urban areas. Therefore, in the context of the dynamic property market, factors related to the third dimension (3D) need to be considered. Current hedonic price modelling (HPM) studies have little explicit consideration for the third dimension, which may have a significant influence on modelling property values in complex urban environments. Therefore, our research aims to narrow the cognitive gap of the missing third dimension by assessing both 2D and 3D HPM and identifying important 3D factors for spatial analysis and visualisation in the selected study area, Xi’an, China. The statistical methods we used for 2D HPM are ordinary least squares (OLS) and geographically weighted regression (GWR). In 2D HPM, they both have very low R2 (0.111 in OLS and 0.217 in GWR), showing a very limited generalisation potential. However, a significant improvement is observed when adding 3D factors, namely view quality, sky view factor (SVF), sunlight and property orientation. The obtained higher R2 (0.414) shows the importance of the third dimension or—3D factors for HPM. Our findings demonstrate the necessity to include such factors into HPM and to develop 3D models with a higher level of details (LoD) to serve more purposes such as fair property taxation.

Download Full-text

TESTING THE IMPACT OF 2D GENERALISATION ON 3D MODELS – EXPLORING ANALYSIS OPTIONS WITH AN OFF-THE-SHELF SOFTWARE PACKAGE

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-4-w10-119-2018 ◽

2018 ◽

Vol XLII-4/W10 ◽

pp. 119-126

Author(s):

E. Muñumer Herrero ◽

C. Ellul ◽

J. Morley

Keyword(s):

3D Models ◽

3D Analysis ◽

Spatial Analyses ◽

3D City Models ◽

The Third ◽

The Past ◽

Processing Times ◽

Third Dimension ◽

The Impact ◽

City Models

Abstract. Popularity and diverse use of 3D city models has increased exponentially in the past few years, providing a more realistic impression and understanding of cities. Often, 3D city models are created by elevating the buildings from a detailed 2D topographic base map and subsequently used in studies such as solar panel allocation, infrastructure remodelling, antenna installations or even tourist guide applications. However, the large amount of resulting data slows down rendering and visualisation of the 3D models, and can also impact the performance of any analysis. Generalisation enables a reduction in the amount of data – however the addition of the third dimension makes this process more complex, and the loss of detail resulting from the process will inevitably have an impact on the result of any subsequent analysis.While a few 3D generalization algorithms do exist in a research context, these are not available commercially. However, GIS users can create the generalised 3D models by simplifying and aggregating the 2D dataset first and then extruding it to the third dimension. This approach offers a rapid generalization process to create a dataset to underpin the impact of using generalised data for analysis. Specifically, in this study, the line of sight from a tall building and the sun shadow that it creates are calculated and compared, in both original and generalised datasets. The results obtained after the generalisation process are significant: both the number of polygons and the number of nodes are minimized by around 83% and the volume of 3D buildings is reduced by 14.87%. As expected, the spatial analyses processing times are also reduced. The study demonstrates the impact of generalisation on analytical results – which is particularly relevant in situations where detailed data is not available and will help to guide the development of future 3D generalisation algorithms. It also highlights some issues with the overall maturity of 3D analysis tools, which could be one factor limiting uptake of 3D GIS.

Download Full-text

Sky View Factors from Synthetic Fisheye Photos for Thermal Comfort Routing—A Case Study in Phoenix, Arizona

Urban Planning ◽

10.17645/up.v2i1.855 ◽

2017 ◽

Vol 2 (1) ◽

pp. 19-30 ◽

Cited By ~ 42

Author(s):

Ariane Middel ◽

Jonas Lukasczyk ◽

Ross Maciejewski

Keyword(s):

Thermal Comfort ◽

Urban Form ◽

Urban Areas ◽

Meteorological Data ◽

Routing Algorithm ◽

Google Earth ◽

Urban Environments ◽

Tree Planting ◽

Outdoor Thermal Comfort ◽

View Factor

The Sky View Factor (SVF) is a dimension-reduced representation of urban form and one of the major variables in radiation models that estimate outdoor thermal comfort. Common ways of retrieving SVFs in urban environments include capturing fisheye photographs or creating a digital 3D city or elevation model of the environment. Such techniques have previously been limited due to a lack of imagery or lack of full scale detailed models of urban areas. We developed a web based tool that automatically generates synthetic hemispherical fisheye views from Google Earth at arbitrary spatial resolution and calculates the corresponding SVFs through equiangular projection. SVF results were validated using Google Maps Street View and compared to results from other SVF calculation tools. We generated 5-meter resolution SVF maps for two neighborhoods in Phoenix, Arizona to illustrate fine-scale variations of intra-urban horizon limitations due to urban form and vegetation. To demonstrate the utility of our synthetic fisheye approach for heat stress applications, we automated a radiation model to generate outdoor thermal comfort maps for Arizona State University’s Tempe campus for a hot summer day using synthetic fisheye photos and on-site meteorological data. Model output was tested against mobile transect measurements of the six-directional radiant flux density. Based on the thermal comfort maps, we implemented a pedestrian routing algorithm that is optimized for distance and thermal comfort preferences. Our synthetic fisheye approach can help planners assess urban design and tree planting strategies to maximize thermal comfort outcomes and can support heat hazard mitigation in urban areas.

Download Full-text

Adding the third dimension—A new tool for constructing 3D models of the airway from 2D bronchoscopic video

International Journal of Pediatric Otorhinolaryngology ◽

10.1016/j.ijporl.2009.05.009 ◽

2009 ◽

Vol 73 (9) ◽

pp. 1202-1207 ◽

Cited By ~ 3

Author(s):

Matthew Bromwich ◽

Shanmugam Murugappan ◽

J. Paul Willging

Keyword(s):

3D Models ◽

The Third ◽

Third Dimension

Download Full-text

Geometrical Assessment of Sunlit and Shaded Area of Urban Trees Based on Aligned Orthographic Views

Atmosphere ◽

10.3390/atmos12080968 ◽

2021 ◽

Vol 12 (8) ◽

pp. 968

Author(s):

Marcel Gangwisch ◽

Dominik Fröhlich ◽

Andreas Christen ◽

Andreas Matzarakis

Keyword(s):

Urban Areas ◽

Longwave Radiation ◽

Strong Relationship ◽

Urban Environments ◽

Urban Trees ◽

View Factor ◽

Urban Architecture ◽

Solar Altitude ◽

Radiation Fluxes ◽

Microscale Model

To quantify the ecosystem services of trees in urban environments, it is necessary to assess received direct solar radiation of each tree. While the Sky View Factor (SVF) is suitable for assessing the total incoming short- and longwave radiation fluxes, its information is limited to specific points in space. For a spatial analysis, it is necessary to sample the area for SVF. A new geometrical method, Area View Factor (AVF), for the calculation of sunlit areas is proposed. AVF is the ratio of the unhidden, projected surface of an object to the whole projected surface of an object in a complex environment. Hereby, a virtual, orthographic camera is oriented in accordance to the sun’s position in the 3D model domain. The method is implemented in the microscale model SkyHelios, utilizing efficient rendering techniques to assess AVF of all urban trees in parallel. The method was applied to Rieselfeld in Freiburg, Germany. The assessed sunlit area is compared to the SVF at the top of each tree and solar altitude angle, revealing a strong relationship between sunlit areas to solar altitude angles. This study shows that AVF is an efficient methodology to assess received direct radiation of urban trees. Based on AVF, it is possible to identify urban areas with shaded and sunlit trees, but it can also be applied to other objects in complex environments. Therefore, AVF is applicable for urban architecture or energetic research questions.

Download Full-text

Automatic Procedural 3d Modelling of Buildings

Tehnički glasnik ◽

10.31803/tg-20180713143638 ◽

2018 ◽

Vol 12 (3) ◽

pp. 166-173

Author(s):

Robert Župan ◽

Stanislav Frangeš

Keyword(s):

Large Scale ◽

3D Visualization ◽

Three Dimensional ◽

3D Models ◽

Automatic Generation ◽

Urban Environments ◽

Second Step ◽

Complex Geometries ◽

The Third ◽

New Procedures

The problem of modelling, especially of large-scale virtual urban environments such as city areas is today very challenging for cartographers. Cities are difficult to model in detail because of their often complex geometries. This paper describes the applied and tested new procedures for the development of a test three-dimensional urban area model using the Esri CityEngine software, which is based on procedural modelling. This process involves three steps. The first step is to collect the available data, as well as the Digital Model Relief data. The second step is to create a Computer Generated Architecture (CGA) file that contains a set of rules used by the software for an automatic generation of the model. The third step is to create and visualize 3D models in the CityEngine software because it can be programmed, for example, according to the rules of cartographic visualization. The Level of Detail (LOD) 2 was reconstructed. Several potential uses of such 3D visualization are also described.

Download Full-text

CITY RECONSTRUCTION FROM AIRBORNE LIDAR: A COMPUTATIONAL GEOMETRY APPROACH

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-iv-4-w8-19-2019 ◽

2019 ◽

Vol IV-4/W8 ◽

pp. 19-26

Author(s):

J.-P. Bauchet ◽

F. Lafarge

Keyword(s):

Computational Geometry ◽

Urban Areas ◽

3D Models ◽

Urban Environments ◽

Airborne Lidar ◽

Polygonal Meshes ◽

Building Reconstruction

Abstract. We introduce a pipeline that reconstructs buildings of urban environments as concise polygonal meshes from airborne LiDAR scans. It consists of three main steps: classification, building contouring, and building reconstruction, the two last steps being achieved using computational geometry tools. Our algorithm demonstrates its robustness, flexibility and scalability by producing accurate and compact 3D models over large and varied urban areas in a few minutes only.

Download Full-text