This research is primarily focused on utilizing available airborne LiDAR data and spatial data from the OpenStreetMap (OSM) database to generate 3D models of buildings for a large-scale urban area. ...The city center of Ljubljana, Slovenia, was selected for the study area due to data availability and diversity of building shapes, heights, and functions, which presented a challenge for the automated generation of 3D models. To extract building heights, a range of data sources were utilized, including OSM attribute data, as well as georeferenced and classified point clouds and a digital elevation model (DEM) obtained from openly available LiDAR survey data of the Slovenian Environment Agency. A digital surface model (DSM) and digital terrain model (DTM) were derived from the processed LiDAR data. Building outlines and attributes were extracted from OSM and processed using QGIS. Spatial coverage of OSM data for buildings in the study area is excellent, whereas only 18% have attributes describing external appearance of the building and 6% describing roof type. LASTools software (rapidlasso GmbH, Friedrichshafener Straße 1, 82205 Gilching, GERMANY) was used to derive and assign building heights from 3D coordinates of the segmented point clouds. Various software options for procedural modeling were compared and Blender was selected due to the ability to process OSM data, availability of documentation, and low computing requirements. Using procedural modeling, a 3D model with level of detail (LOD) 1 was created fully automated. After analyzing roof types, a 3D model with LOD2 was created fully automated for 87.64% of buildings. For the remaining buildings, a comparison of procedural roof modeling and manual roof editing was performed. Finally, a visual comparison between the resulting 3D model and Google Earth’s model was performed. The main objective of this study is to demonstrate the efficient modeling process using open data and free software and resulting in an enhanced accuracy of the 3D building models compared to previous LOD2 iterations.
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.
At the beginning of any crisis, including pandemics, it is very important to provide timely information to expert headquarters at the local and global level so that they can make daily decisions ...about measures and behavior of the population. Support for this can be a combination of analytical and statistical data together with the locations from which these data were collected. Part of the cartographic visualization deals precisely with the ways of designing and visual presentation based on which it would be clear to the user where the biggest hotspots and the biggest changes are compared to the previous period. The paper describes the origin and proposal of the original dashboard for monitoring the COVID pandemic in Croatia. The dashboard contains and combines thematic data and displays it with the layout and design carefully determined. The goal is for the data to be implemented as soon as it is available to the public. Similar works available on the Internet are also shown. The entire course of making the dashboard for the COVID pandemic and dissemination data is described, as well as data sources, software, problems encountered and solutions.
In this paper we combined layers created from several terrain rendering techniques, namely a shaded relief rendered in the free and open-source 3D computer graphics software Blender, a hillshade ...created in the free and opensource Geographic Information System (GIS) software QGIS, a hypsometric coloured Digital Elevation Model (DEM) and a draped digital orthophoto. Following a recent trend in the cartographic community towards using Blender, we tried to improve the standard relief visualization in common GIS software by blending it with a shaded relief rendered in Blender. Using different QGIS blending modes and opacity values we achieved different graphic visualizations. To compare and evaluate the suitability of different rendering techniques we chose national park Risnjak located in Croatia because of its specific and diverse terrain landforms. After comparing different input layers and parameter sets, we selected the blending combination which is best suited for visualizing terrain characteristics of all Croatian national parks. The result is a shaded relief created for every national park which is combined from a shaded relief rendered in Blender, a hillshade created in QGIS, a hypsometric coloured DEM and a draped digital orthophoto.
Sjenčanje reljefa u švicarskom stilu učinkovita je i vizualno atraktivna metoda za predstavljanje treće dimenzije reljefa na dvodimenzionalnoj karti. Takva metoda korištena je za predstavljanje ...terena na prirodan, istančan i intuitivan način. Važan element kod takvog načina sjenčanja reljefa je upotreba prilagođene ljestvice boja i efekta atmosferske perspektive. U prvom dijelu ovoga rada opisan je grafički i tehnički razvoj, te osnovna načela sjenčanja reljefa u švicarskom stilu. Drugi dio rada prikazuje proces izrade sjenčanog reljefa izvedenog iz digitalnog modela reljefa korištenjem isključivo funkcionalnosti dostupnih unutar slobodnog geoinformacijskog sustava otvorenog koda QGIS. Nadahnuti djelovanjem švicarskog kartografa Eduarda Imhofa na području vizualizacije reljefa, izrađena je digitalna karta Švicarske primjenjujući tehnike klasične švicarske škole. Proces izrade karte sastoji se od nekoliko koraka pri čemu najvažniji dio čine izrada pojedinih slojeva karte dobivenih iz digitalnog modela reljefa (jednosmjerno sjenčanje, višesmjerno sjenčanje, zračna perspektiva), izrada hipsometrijske ljestvice boja po uzoru na karte švicarskih kartografa, pronalazak optimalnih vrijednosti parametara pojedinih slojeva karte, te završna grafička obrada karte.
This paper compares the indicators of spatial development for the road network of Croatia towards chosen countries in Europe and on a county level in Croatia. It also shows the number of traffic ...accidents per counties and links it with indicators of spatial development. The paper presents the results of the research of spatial distribution of traffic accidents in Croatia by counties. An example of a hazardous site identification on the A6 motorway is provided by the accident data report. All the comparisons and analyzes are presented graphically in the form of charts and cartography-related views in the MapViewer 7 software. The result shows that there are significant differences between counties. It is often the case that similar values relate to counties derived from similar level of development and similar number of population. From the results it is concluded that the number of traffic accidents is more dependent on the population than on road network length in relation to the surface of the county. To invest in remediation of hazardous sites, it is necessary to consider more factors than repeated traffic accidents.
This paper describes the process of creating a useful geographic information system (GIS) viewer on the web that shows the map of the old town of Šibenik, which is located in the heart of Dalmatia. ...Spatial and attribute data is the core of every geoinformation system so therefore a database with objects of interest (cultural and historical sights in the old town centre) was created. The main goal of the project was to develop a GIS viewer for tourist purposes, but also to provide basic information about the current situation of building for investors and conservators. The rules of cartographic generalization, visualization and digital cartography were taken into account. The paper will describe theoretical and practical aspects of creating a geoinformation system. The theoretical part explains basic terms such as web cartography, web maps, databases and geoinformation systems. The practical part shows the working process which goes from collecting the data and processing it into the database, to creating the map and publishing it on the Internet.
Visual Analytics of Forest and other Roads Density Zupan, Robert; Franges, Stanislav; Vinkovic, Adam ...
IOP conference series. Earth and environmental science,
01/2019, Volume:
221, Issue:
1
Journal Article
Peer reviewed
Open access
This paper compares the indicators of spatial development for the road network of Croatia towards chosen countries in Europe and on a county level in Croatia. It also shows the number of traffic ...accidents per counties and links it with indicators of spatial development. The paper presents the results of the research of spatial distribution of traffic accidents in Croatia by counties. An example of a hazardous site identification on the A6 motorway is provided by the accident data report. All the comparisons and analyzes are presented graphically in the form of charts and cartography-related views in the MapViewer 7 program. From the results it can be seen that there are significant differences between the counties and it is often the case that similar values for the counties derived from similar level of development and similar number of population. From the results it is concluded that the number of traffic accidents is more dependent on the population than the length of the road network in relation to the surface of the county. To invest in remediation of hazardous sites, it is necessary to consider more factors than repeated traffic accidents.
Određivanje površina s karata Frančula, Nedjeljko; Lapaine, Miljenko; Župan, Robert ...
Geodetski list,
12/2021, Volume:
75 (98), Issue:
4
Paper
Open access
Danas, kada je većina prostornih podataka u digitalnom obliku, površine poligona moguće je određivati s karata izrađenima u bilo kojoj kartografskoj projekciji jer digitalni oblik omogućuje da se pri ...mjerenju eliminiraju deformacije projekcije. Pri određivanju površina s karata Google Mapsa i Google Eartha dobivaju se vrijednosti oslobođene deformacija zbog kartografske projekcije. I neki GIS softveri (npr. QGIS, ArcGIS online, Global Mapper) kao rezultat mjerenja daju površine na elipsoidu. Uz to QGIS omogućuje i računanje površine u kartografskoj projekciji karte bez uzimanja u obzir deformacije zbog projekcije. CAD softveri (npr. AutoCAD Map) i kartografski softveri (npr. OCAD) kao rezultat mjerenja daju površinu u kartografskoj projekciji karte bez uzimanja u obzir deformacije nastale zbog projekcije. U svakom od navedenih softvera određena je površina Grenlanda na karti preuzetoj s OpenStreetMapa u web-Mercatorovoj projekciji. Ako se površina računa u kartografskoj projekciji u kojoj je izrađena karta, pa bila to i ekvivalentna projekcija, stranice graničnog poligona moraju biti dovoljno kratke da se može smatrati da se geodetska linija preslikala kao dužina i uz to treba uzeti u obzir deformacije zbog projekcije.
Our ultimate goal is to probe the nature of the collimator of the outflows in the pre-planetary nebula CRL 618. CRL 618 is uniquely suited for this purpose owing to its multiple, bright, and ...carefully studied finger-shaped outflows east and west of its nucleus. We compare new Hubble Space Telescope images to images in the same filters observed as much as 11 yr ago to uncover large proper motions and surface brightness changes in its multiple finger-shaped outflows. The expansion age of the ensemble of fingers is close to 100 yr. We find strong brightness variations at the fingertips during the past decade. Deep IR images reveal a multiple ring-like structure of the surrounding medium into which the outflows propagate and interact. Tightly constrained three-dimensional hydrodynamic models link the properties of the fingers to their possible formation histories. We incorporate previously published complementary information to discern whether each of the fingers of CRL 618 are the results of steady, collimated outflows or a brief ejection event that launched a set of bullets about a century ago. Finally, we argue on various physical grounds that fingers of CRL 618 are likely to be the result of a spray of clumps ejected at the nucleus of CRL 618 since any mechanism that form a sustained set of unaligned jets is unprecedented.
PDF
