Browsing by Author "Julin, Arttu"
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Item 3D Point Cloud Data in Conveying Information for Local Green Factor Assessment(MDPI AG, 2021-11-11) Jaalama, Kaisa; Kauhanen, Heikki; Keitaanniemi, Aino; Rantanen, Toni; Virtanen, Juho-Pekka; Julin, Arttu; Vaaja, Matti Tapio; Ingman, Matias; Ahlavuo, Marika; Hyyppä, Hannu; MeMo; Geoinformatics; Department of Built EnvironmentThe importance of ensuring the adequacy of urban ecosystem services and green infrastructure has been widely highlighted in multidisciplinary research. Meanwhile, the consolidation of cities has been a dominant trend in urban development and has led to the development and implementation of the green factor tool in cities such as Berlin, Melbourne, and Helsinki. In this study, elements of the green factor tool were monitored with laser-scanned and photogrammetrically derived point cloud datasets encompassing a yard in Espoo, Finland. The results show that with the support of 3D point clouds, it is possible to support the monitoring of the local green infrastructure, including elements of smaller size in green areas and yards. However, point clouds generated by distinct means have differing abilities in conveying information on green elements, and canopy covers, for example, might hinder these abilities. Additionally, some green factor elements are more promising for 3D measurement-based monitoring than others,such as those with clear geometrical form. The results encourage the involvement of 3D measuring technologies for monitoring local urban green infrastructure (UGI), also of small scale.Item Applying photogrammetry to reconstruct 3D luminance point clouds of indoor environments(Earthscan, 2022-01-02) Kurkela, Matti; Maksimainen, Mikko; Julin, Arttu; Virtanen, Juho-Pekka; Männistö, Ilari; Vaaja, Matti Tapio; Hyyppä, Hannu; Department of Built Environment; MeMo; GeoinformaticsComputer-aided 3D modelling is the standard design method in the architecture, engineering, construction, owner, operator (AECOO) industry and in lighting design. Applying a photogrammetric process, a sequence of images is used to reconstruct the geometry of a space or an object in a 3D model. Likewise, a calibrated digital camera is utilized to measure the surface luminance values of an environment or an object. We propose a workflow in which the geometry and the luminance values are measured simultaneously by combining these two measurement methods. The pipeline has been assessed and validated through the application to a case study, the Aalto Hall (Aalto University, Espoo, Finland), in order to understand its potential.Item Auditing an urban park deck with 3D geovisualization—A comparison of in-situ and VR walk-along interviews(Elsevier GmbH, 2022-10) Jaalama, Kaisa; Rantanen, Toni; Julin, Arttu; Fagerholm, Nora; Keitaanniemi, Aino; Virtanen, Juho Pekka; Handolin, Hannu; Vaaja, Matti; Hyyppä, Hannu; Department of Built Environment; Geoinformatics; MeMoVirtual reality-based urban audit methods are gaining increasing attention; however, most virtual urban audit studies have focused on panoramic views. The 3D city model-based geovisualizations have remained until now rather unexplored in user studies for urban audits and for communicative urban planning. We explored the feasibility of a 3D geovisualization-based urban audit in virtual reality (VR) for assessing the perceived quality of an urban park deck in Helsinki, Finland. For this purpose, we created a photorealistic and geometrically accurate 3D model (Bryga 3D) based on photogrammetric and laser scanning data. Bryga 3D was implemented on a game engine to be viewed with a head-mounted VR display. Bryga 3D's ability to convey information in a subjective urban audit, that is, subjectively perceived affordances of a park deck, was tested in a walk-along interview study comparing auditing in situ and via the VR method. A comparison of the results with in-situ (n = 13) and VR interviews (n = 21) show that the perception of several tangible elements, such as spatial division, landforms, paths, and chairs when using Bryga VR was similar to when performed in situ. Perception of vegetation was weaker in VR in terms of its detailed quality, which somewhat affected the presented development ideas and assessment of the seasonal context. Also, weaker perception of the surroundings and city context affected the results in VR. However, considering that Bryga 3D presents an example of a highly automated 3D city modeling process conducted with minimal manual work, its results are encouraging for future attempts to advance such realizations for the purposes of communicative urban planning. 3D geovisualization-based virtual audits could be used when urban green space audits are not possible or when they are demanding to implement in situ.Item Augmented Reality and the Role of Optical Tracking(2017-04-28) Putkiranta, Pauli; Julin, Arttu; Insinööritieteiden korkeakoulu; Vermeer, MartinItem Automated building reconstruction from airborne laser scanning(2012) Julin, Arttu; Rönnholm, Petri; Davidsson, Jonne; Maankäyttötieteiden laitos; Insinööritieteiden korkeakoulu; School of Engineering; Haggrén, HenrikThe objective of this M.Sc. thesis was to investigate how aerial laser scanner data, and especially its point density, affects the performance of the automated building reconstruction. The literature review of this thesis focuses on giving an overview of a point cloud based automated building reconstruction as most of the existing literature is focused only on individual aspects of the topic. The aerial laser scanner data used in this work was acquired in the area of the city of Pietarsaari in spring 2012. The automated building reconstruction test was made with the point cloud processing software of Terrasolid Oy. A base map of class 1e was used as a reference data for validating the reconstruction results. In order to investigate the effects of the point density, five different datasets (10; 5; 2.5; 1.25 and 0.6 points / m2) were produced from the original point cloud by scaling down the point densities. The aerial laser scanning data consisted of three different test areas with distinct types of buildings: a residential area, an apartment building area and an industrial area. Results show that the average plane accuracy of the automatically reconstructed building models is below 50 cm when the point density is above 5.5 points / m2, which meets the standard error requirements for a measured point in a class 2 base map. Furthermore, the average height accuracy of the models meets the class 1e requirements in a flat terrain. Moreover, the results of this study indicate clearly that the point density affects the performance of automated building reconstruction. According to the measurements and a visual interpretation the quality of the reconstructed building models deteriorates as the point density decreases.Item Automated multi-sensor 3D reconstruction for the web(MDPI AG, 2019-05-08) Julin, Arttu; Jaalama, Kaisa; Virtanen, Juho Pekka; Maksimainen, Mikko; Kurkela, Matti; Hyyppä, Juha; Hyyppä, Hannu; Department of Built Environment; MeMoThe Internet has become a major dissemination and sharing platform for 3D content. The utilization of 3D measurement methods can drastically increase the production efficiency of 3D content in an increasing number of use cases where 3D documentation of real-life objects or environments is required. We demonstrated a developed, highly automated and integrated content creation process of providing reality-based photorealistic 3D models for the web. Close-range photogrammetry, terrestrial laser scanning (TLS) and their combination are compared using available state-of-the-art tools in a real-life project setting with real-life limitations. Integrating photogrammetry and TLS is a good compromise for both geometric and texture quality. Compared to approaches using only photogrammetry or TLS, it is slower and more resource-heavy but combines complementary advantages of each method, such as direct scale determination from TLS or superior image quality typically used in photogrammetry. The integration is not only beneficial, but clearly productionally possible using available state-of-the-art tools that have become increasingly available also for non-expert users. Despite the high degree of automation, some manual editing steps are still required in practice to achieve satisfactory results in terms of adequate visual quality. This is mainly due to the current limitations of WebGL technology.Item Browser Based 3D for the Built Environment(2018-12-13) Virtanen, Juho-Pekka; Hyyppä, Hannu; Kurkela, Matti; Vaaja, Matti; Puustinen, Tuulia; Jaalama, Kaisa; Julin, Arttu; Pouke, Matti; Kukko, Antero; Turppa, Tuomas; Zhu, Lingli; Ojala, Timo; Hyyppä, Juha; MeMo; Geoinformatics; Real Estate; University of Oulu; Finnish Geospatial Research Institute; Department of Built EnvironmentDigital 3D models have become a central tool for geo-information. For many participatory and collaborative applications, distributing these models easily is essential. Several technical solutions exist for creating online systems that facilitate the study of 3D models in the context of the built environment. First, we provide an overview on browser based interactive 3D visualizations through presenting a set of existing systems applied in Finland, and discussing their common properties and differences. Second, we experiment with an online 3D application development platform in order to obtain first-hand experience. The systems studied show a high potential for browser based 3D applications: interactive visualizations with multi-user characteristics and dynamic elements can be built by leveraging the 3D web technologies. Finally, we suggest a list of essential capabilities for online 3D visualization, covering the spectrum of possibilities available in modern web-based 3D.Item Change detection of urban vegetation from terrestrial laser scanning and drone photogrammetry(2023-08-21) Shafaat, Osamabin; Julin, Arttu; Kauhanen, Heikki; Insinööritieteiden korkeakoulu; Vaaja, MattiUrban areas experience continuous transformations, impacting the urban vegetation, particularly urban trees. The expansion of urban landscapes directly impacts green spaces and vegetation within cities. Urban vegetation plays a crucial role in improving the urban environment, benefiting residents' well-being, air quality, and temperature regulation. Monitoring changes in urban vegetation is therefore essential, considering the environmental and well-being aspects. This study focuses on change detection using terrestrial laser scanning (TLS) and drone photogrammetry, utilizing three-dimensional (3D) point cloud data. Change detection compares multi-temporal datasets to analyze variations in a geographic region. TLS and drone photogrammetry techniques have gained popularity for monitoring urban vegetation, as they enable the acquisition of detailed 3D information. Point cloud data captures 3D information, enabling detailed change detection and 3D visualization of urban vegetation. This enhances the level of detail and information provided by the methodologies. The objective is to estimate the growth of urban vegetation in a specific area within Helsinki's Malminkartano region during the spring and fall seasons of 2022 using multi-temporal TLS, UAV photogrammetry, and their integration. The research examines the suitability of different point cloud datasets acquired with different sensors and parameters for change detection analysis, identifying potential differences, challenges, and proposed solutions. Three distinct methods, namely C2C, C2M, and M3C2 are employed for point cloud comparison. The results highlighted that manual processing is required to make the point cloud datasets comparable, with significant issues related to differences in point density and resolution. The sparser UAV photogrammetry datasets pose limitations on detailed analysis for change detection. The visual results reveal that TLS datasets detect changes in urban vegetation up to 2m, while UAV photogrammetry and integrated datasets up to 2.8m. However, applying a threshold at a 95% confidence level, 80-90% of significant changes in TLS datasets are observed up to 0.5m, up to 1m in UAV datasets, and up to 0.5m in integrated datasets. These changes represent the growth of urban vegetation during the leaf-off and leaf-on seasons examined. Overall, the utilized datasets provide valuable insights into changes in urban vegetation within the study area.Item Characterizing 3d city modeling projects : Towards a harmonized interoperable system(2018-02-01) Julin, Arttu; Jaalama, Kaisa; Virtanen, Juho Pekka; Pouke, Matti; Ylipulli, Johanna; Vaaja, Matti; Hyyppä, Juha; Hyyppä, Hannu; Department of Built Environment; MeMo; Geoinformatics; University of Oulu; Finnish Geospatial Research Institute3D city models have become common geospatial data assets for cities that can be utilized in numerous fields, in tasks related to planning, visualization, and decision-making among others. We present a study of 3D city modeling focusing on the six largest cities in Finland. The study portrays a contradiction between the realized 3D city modeling projects and the expectations towards them: models do not appear to reach the broad applicability envisioned. In order to deal with contradiction and to support the development of future 3D city models, characteristics of different operational cultures in 3D city modeling are presented, and a concept for harmonizing the 3D city modeling is suggested.Item CityGML building model production from airborne laser scanning(2016-01-25) Jokela, Joonas; Rönnholm, Petri; Julin, Arttu; Insinööritieteiden korkeakoulu; Haggrén, Henrik3D city models have become an important tool in many applications across different fields. Usually these 3D city models only represent the geometrical attributes of the city, which enables easy visualization of cities. Yet, different thematic queries, analysis tasks, and spatial data mining are out of the reach of models that only offer us information about their geometry. CityGML 3D city models bring an addition of semantic information to the models. In this thesis, the process and different techniques of building reconstruction from airborne laser scanning are explained. CityGML standard will also be explained and what has to be done in order to go from 3D building models to CityGML. The main focus of this thesis was to study how well it is possible to automatically create CityGML 2.0 3D city models from data collected only by airborne laser scanning. CityGML has five different levels-of-detail indicating the level of precision of the building. LOD1 and LOD2 were the most important levels for this thesis, and so it was tested how well different software were able to export reconstructed building models in the CityGML format with these precision levels. These exports were checked against the official specification of CityGML to see how well they met the requirements. It was also explained what more would be needed for the process and data, in order to produce higher quality models in LOD3. Two different test areas were chosen with different building and roof types. One area included detached houses, some partly covered with vegetation, and another area included mainly apartment houses. The thesis shows that as of now, it is still quite challenging to automatically produce city models that are in line with the CityGML 2.0 standard. The model driven methods had problems when it came to building installations, such as chimneys. These could not be modelled with software that used model driven methods. Data driven methods on the other hand had problems when it came to the conversion from the building models to the CityGML format. Terrain and terrain intersection curve also turned out to be more difficult to model than anticipated. Most of the software used in this thesis were not able to automatically handle the addition of these elements. The elements were possible to add later on to the CityGML file but only with use of additional software tools.Item CREATING OPEN ONLINE APPLICATIONS WITH GEOSPATIAL INTERFACES - CASE STUDY “PALVELUTUTKA”(Finnish Society of Geodesy and Photogrammetry and Geoinformatics research group, Aalto University School of Engineering, 2021-11-19) Virtanen, Juho-Pekka; Julin, Arttu; Jaalama, Kaisa; Hyyppä, Hannu; MeMo; Department of Built EnvironmentThree-dimensional city models are an increasingly common data set maintained by many cities globally. At the same time, the focus of research has shifted from their production to their utilization in application development. We present the implementation of a demonstrator application combining the online visualization of a 3D city information model with the data from an application programming interface. By this, we aim to demonstrate the combined use of city APIs and 3D geospatial assets, promote their use for application development and show the performance of existing, openly available tools for 3D city model application development.Item Depth camera indoor mapping for 3D virtual radio play(2018-06) Virtanen, Juho-Pekka; Kurkela, Matti; Turppa, Tuomas; Vaaja, Matti; Julin, Arttu; Kukko, Antero; Hyyppä, Juha; Ahlavuo, Marika; Edén, Jessica; Haggren, Henrik; Hyyppä, Hannu; MeMo; Department of Built Environment; Finnish Geospatial Research Institute; Geoinformatics; Svenska YLEBy combining game engines with indoor mapping, it is possible to create interactive virtual environments that represent the real world. In this paper a virtual version of an audio installation in a historic building is produced, where the user freely explores the building and experiences a set of audio clips, creating a virtual radio play. A depth camera indoor mapping system, Matterport, captured a set of staged interiors. The aim was to evaluate the quality and usability of the indoor models and to demonstrate applying them in 3D application development. The quality of the models was evaluated by comparison with laser scanning, revealing limitations with Matterport: increasing the size of the measured area lowered the level of detail and accuracy of volumetric models. The quality of textures was not affected by this limitation, maintaining the appearance of models. To obtain optimised models for mobile 3D applications, a manual revision process was applied.Item Evaluating the quality of TLS point cloud colorization(MDPI AG, 2020-09) Julin, Arttu; Kurkela, Matti; Rantanen, Toni; Virtanen, Juho Pekka; Maksimainen, Mikko; Kukko, Antero; Kaartinen, Harri; Vaaja, Matti T.; Hyyppä, Juha; Hyyppä, Hannu; Department of Built Environment; MeMo; GeoinformaticsTerrestrial laser scanning (TLS) enables the efficient production of high-density colored 3D point clouds of real-world environments. An increasing number of applications from visual and automated interpretation to photorealistic 3D visualizations and experiences rely on accurate and reliable color information. However, insufficient attention has been put into evaluating the colorization quality of the 3D point clouds produced applying TLS. We have developed a method for the evaluation of the point cloud colorization quality of TLS systems with integrated imaging sensors. Our method assesses the capability of several tested systems to reproduce colors and details of a scene by measuring objective image quality metrics from 2D images that were rendered from 3D scanned test charts. The results suggest that the detected problems related to color reproduction (i.e., measured differences in color, white balance, and exposure) could be mitigated in data processing while the issues related to detail reproduction (i.e., measured sharpness and noise) are less in the control of a scanner user. Despite being commendable 3D measuring instruments, improving the colorization tools and workflows, and automated image processing pipelines would potentially increase not only the quality and production efficiency but also the applicability of colored 3D point clouds.Item Improving the utilization of close-range photogrammetry and terrestrial laser scanning for photorealistic urban 3D modeling(Aalto University, 2021) Julin, Arttu; Hyyppä, Hannu, Prof., Aalto University, Finland; Hyyppä, Juha, Prof., Finnish Geospatial Research Institute, Finland; Virtanen, Juho-Pekka, Aalto University, Finland; Rakennetun ympäristön laitos; Department of Built Environment; Research Institute of Measuring and Modeling for the Built Environment (MeMo); Insinööritieteiden korkeakoulu; School of Engineering; Vaaja, Matti T., Prof., Aalto University, Department of Built Environment, FinlandPhotorealistic urban 3D models have become valuable and much-requested tools for visualizing, managing, developing, and understanding growing and densifying urban environments in diverse use cases ranging from interactive digital twins to engaging XR experiences. Close-range photogrammetry and terrestrial laser scanning (TLS) can produce accurate, detailed, and photorealistic 3D models from complex urban environments. These close-range 3D measuring techniques are well acknowledged for their complementary benefits and high level of geometric accuracy. However, the quality of the model appearance has been rarely assessed for photorealism. Furthermore, the 3D model itself does not guarantee its utilization and usefulness, though the application platform plays a significant role in putting it into beneficial use. The dissertation developed ways to improve the utilization of close-range photogrammetry and TLS for photorealistic urban 3D modeling. First, relevant application platforms were identified by studying real-life urban 3D modelling activities. Second, automated multi-sensor urban 3D modeling was experimented for a photorealistic web-based application and the quality of the produced models (close-range photogrammetry, TLS, and a combination of them) was evaluated from the perspective of both model geometry and textures. Finally, the quality of TLS point cloud colorization was evaluated by analyzing the TLS instrument's capability to reproduce color and details in the scene. The results identified real-time 3D platforms (i.e., game engines and virtual globes) as the most relevant application platforms for utilizing photorealistic urban 3D models. Integrating close-range photogrammetry and TLS proved a good compromise for efficient model production between the superior texture quality of photogrammetry and the better geometric quality of TLS. Finally, a new method was developed for evaluating the quality of TLS point cloud colorization, which revealed quality differences among all tested commercial TLS instruments and settings. The dissertation research improved the utilization of and offered a deeper understanding of the efficiency and quality of close-range photogrammetry and TLS for photorealistic urban 3D modeling. For photorealistic use cases, it is crucial to understand the quality of a 3D model as a combination of geometry and appearance. Together, the close-range 3D measuring methods and real-time 3D platforms enable the efficient and beneficial creation and utilization of highly detailed, photorealistic, urban 3D models in both new and well-established fields.Item Interactive dense point clouds in a game engine(Elsevier Science B.V., 2020-05-01) Virtanen, Juho Pekka; Daniel, Sylvie; Turppa, Tuomas; Zhu, Lingli; Julin, Arttu; Hyyppä, Hannu; Hyyppä, Juha; Department of Built Environment; MeMo; Université Laval; National Land Survey of FinlandWith the development of 3D measurement systems, dense colored point clouds are increasingly available. However, up to now, their use in interactive applications has been restricted by the lack of support for point clouds in game engines. In addition, many of the existing applications for point clouds lack the capacity for fluent user interaction and application development. In this paper, we present the development and architecture of a game engine extension facilitating the interactive visualization of dense point clouds. The extension allows the development of game engine applications where users edit and interact with point clouds. To demonstrate the capabilities of the developed extension, a virtual reality head-mounted display is used and the rendering performance is evaluated. The result shows that the developed tools are sufficient for supporting real-time 3D visualization and interaction. Several promising use cases can be envisioned, including both the use of point clouds as 3D assets in interactive applications and leveraging the game engine point clouds in geomatics.Item INTERACTIVE GEO-INFORMATION IN VIRTUAL REALITY – OBSERVATIONS AND FUTURE CHALLENGES(Copernicus GmbH, 2020-09-03) Virtanen, Juho-Pekka; Julin, Arttu; Handolin, Hannu; Rantanen, Toni; Maksimainen, Mikko; Hyyppä, Juha; Hyyppä, Hannu; Department of Built Environment; MeMoVisualization applications are an increasingly significant component in the field of 3D geo-information. In them, the utilization of consumer grade virtual reality (VR) head mounted displays (HMD) has become a topical research question. It is notable, that in most presented implementations, the VR visualization is accomplished by a game engine. As game engines rely on textured mesh models as their conventional 3D asset format, the challenge in applying photogrammetric or laser scanning data is in producing models than are suitable for game engine use. We present an example of leveraging immersive visualization in geo-information, including the acquisition of data from the intended environment, processing it to a game engine compatible form, developing the required functions on the game engine and finally utilizing VR HMDs to deploy the application. The presented application combines 3D indoor models obtained via a commercial indoor mapping system, a 3D city model segment obtained by processing airborne laser scanning data, and a set of manually created 3D models. The performance of the application is evaluated on two different VR systems. The observed capabilities of interactive VR applications include: 1) intuitive and free exploration of 3D data, 2) ability of operate in different scales, and with different scales of data, 3) integration of different data types (such as 2D imaging and 3D models) in interactive scenes and 4) the possibility to leverage the rich interaction functions offered by the game engine platform. These capabilities could support several use cases in geo-informationItem Maalaserkeilauksen soveltaminen puuston arvonmäärityksessä(2017-08-28) Taivassalo, Tero; Vaaja, Matti; Julin, Arttu; Insinööritieteiden korkeakoulu; Haggrén, HenrikTutkimuksen tärkein tavoite on selvittää maalaserkeilauksen sovellettavuutta ja luotettavuutta metsän arvioinnissa. Diplomityön teoriaosan aiheina ovat puuston maalaserkeilaus ja yleisimpien metsän arviointimenetelmien perusteet. Työn soveltavassa osassa käytettiin maalaserkeilaimella mitattuja aineistoja, joiden avulla demonstroitiin arviointiprosessi kokonaisuudessaan. Työssä käytettiin kahden puun, koivun ja männyn, maalaserkeilauksen tuloksia. Puut oli mitattu sekä tyynellä että tuulisella säällä. Molempien puiden runkojen kokonaistilavuus laskettiin valituilla korkeustasoilla määritettyjen halkaisijoiden perusteella. Tuulen vaikutuksen selvittämiseksi tuloksia vertailtiin tuuliolosuhteiden mukaan. Työssä havaittiin, että maalaserkeilaukseen perustuvaan puun rungon tilavuuden määritysmenetelmään sisältyy merkittäviä epävarmuuksia. Rungon tilavuus voidaan määrittämään luotettavasti noin kahdeksan metrin korkeuteen asti, kun puun korkeus on 15 m. Puun rungon muodon määrittäminen vaikeutuu erityisesti oksista ja puun lehdistä aiheutuvien katveiden vuoksi. Koivun tilavuus on tuulisella säällä tehtyjen mittausten tuloksista määritettynä suurempi kuin tyynen sään aineistosta saadaan, mutta männyn tilavuudessa ero on päinvastoin. Koska määritettyjen halkaisijoiden epävarmuuksista aiheutuva runkojen kokonaistilavuuksien epävarmuus on ainakin samaa suuruusluokkaa kuin tuloksena saatu tuulen vaikutus määritettyihin tilavuuksiin, tuulen vaikutusta laserkeilausten aineistojen avulla määritettyyn runkojen kokonaistilavuuteen ei tässä työssä käytettävissä olleen mittausaineiston perusteella voida arvioida. Kuvitteellisen metsäkiinteistön puuston arvo laskettiin sekä summa-arvo- että tuottoarvomenetelmillä keilatuille puille määritettyjen tilavuuksien ja markkinahintojen perusteella. Tuulen vaikutus on ennakko-odotuksia heikompi. Tuulisen sään mittausaineistolla puuston arvoksi saadaan vain 1,7 prosenttia pienempi kuin tyynen sään aineistolla. Toisaalta koivujen kokonaisarvo on 5,0 prosenttia suurempi tuulisen kuin tyynen sään aineiston perusteella. Sen sijaan mäntyjen arvo on 4,2 prosenttia pienempi tuulisen kuin tyynen sään mittausaineistojen perusteella. Tuottoarvomenetelmällä puuston kokonaisarvoksi saadaan 4–8 prosenttia suurempi arvo kuin summa-arvomenetelmällä.Item Maalaserkeilausaineiston visualisointi virtuaalitodellisuudessa(2019-10-21) Kokkonen, Tia; Julin, Arttu; Insinööritieteiden korkeakoulu; Vaaja, MattiVirtuaalitodellisuuden tavoitteena on tarjota tietokoneella luotuja todentuntuisia ympäristöjä, jotka hyötyvät yksityiskohtaisista ja fotorealistisista 3D-malleista. Laserkeilauksella pystytään tuottamaan nopeasti ja tehokkaasti suuria määriä mittatarkkaa pistepilviaineistoa, jota voidaan tulevaisuudessa hyödyntää huomattavasti nykyistä tehokkaammin virtuaalitodellisuuden sovelluksissa. Tässä tutkimuksessa selvitettiin maalaserkeilatun pistepilviaineiston soveltuvuutta visualisointiin virtuaalitodellisuudessa. Tutkimus on jaettu kirjallisuuskatsaukseen ja tutkimusosioon. Kirjallisuustutkimuksessa esitellään maalaserkeilauksen ja virtuaalitodellisuuden perusperiaatteet, sekä käsitellään pistepilviaineistolle tyypillisiä ominaisuuksia ja sen visualisointiin liittyviä vaatimuksia. Tutkimusosiossa pistepilviaineistoa testattiin tyypiltään ja toimintatavaltaan kolmessa erilaisessa ohjelmistossa: Faro SCENE LT pistepilviaineiston katseluohjelmistossa, selainpohjaisessa 3D-mallien julkaisualustassa Sketchfabissa ja Unity pelimoottoriin saatavilla olevan pistepilvien katseluun tarkoitetun Point Cloud Free Viever –lisäosan avulla. Tutkimusosiossa tehtyjen havaintojen perusteella ilmeni, että kaikkia pistepilven ominaisuuksia ei saatu tutkittujen ohjelmistojen avulla hyödynnettyä tai käyttöönotettua ja valittujen ohjelmistojen toiminallisuuksissa oli merkittäviä eroja niiden erilaisista käyttötarkoituksista johtuen. Yleisesti voitiin kuitenkin todeta, että kaikki ohjelmistot mahdollistavat pistepilvien visualisoinnin virtuaalitodellisuudessa. Tutkimustyön aikana huomattiin teknologioiden jatkuva kehitys VR-laitteiden ja -sovellusten nopeina muutoksina, sekä kuinka vähän aiheesta löytyy tieteellistä tutkimusta vielä. Virtuaalitodellisuuden sovelluksia tullaan hyödyntämään nykyistä laajemmin monilla eri tieteenaloilla, joten pistepilvien tuottamiseen käytettävät 3D-mittaustekniikat sekä aineistojen käsittelyyn tarvittavat ohjelmistot tulevat myös kehittymään entistä nopeammin lähitulevaisuudessa.Item Near Real-Time Semantic View Analysis of 3D City Models in Web Browser(MDPI AG, 2021-03) Virtanen, Juho-Pekka; Jaalama, Kaisa; Puustinen, Tuulia; Julin, Arttu; Hyyppä, Juha; Hyyppä, Hannu; Department of Built Environment; MeMo; Real Estate3D city models and their browser-based applications have become an increasingly applied tool in the cities. One of their applications is the analysis views and visibility, applicable to property valuation and evaluation of urban green infrastructure. We present a near real-time semantic view analysis relying on a 3D city model, implemented in a web browser. The analysis is tested in two alternative use cases: property valuation and evaluation of the urban green infrastructure. The results describe the elements visible from a given location, and can also be applied to object type specific analysis, such as green view index estimation, with the main benefit being the freedom of choosing the point-of-view obtained with the 3D model. Several promising development directions can be identified based on the current implementation and experiment results, including the integration of the semantic view analysis with virtual reality immersive visualization or 3D city model application development platforms.Item Nighttime Mobile Laser Scanning and 3D Luminance Measurement : Verifying the Outcome of Roadside Tree Pruning with Mobile Measurement of the Road Environment(MDPI AG, 2020-07) Maksimainen, Mikko; Vaaja, Matti T.; Kurkela, Matti; Virtanen, Juho-Pekka; Julin, Arttu; Jaalama, Kaisa; Hyyppä, Hannu; Department of Built Environment; MeMo; GeoinformaticsRoadside vegetation can affect the performance of installed road lighting. We demonstrate a workflow in which a car-mounted measurement system is used to assess the light-obstructing effect of roadside vegetation. The mobile mapping system (MMS) includes a panoramic camera system, laser scanner, inertial measurement unit, and satellite positioning system. The workflow and the measurement system were applied to a road section of Munkkiniemenranta, Helsinki, Finland, in 2015 and 2019. The relative luminance distribution on a road surface and the obstructing vegetation were measured before and after roadside vegetation pruning applying a luminance-calibrated mobile mapping system. The difference between the two measurements is presented, and the opportunities provided by the mobile 3D luminance measurement system are discussed.
