scholarly journals Morphable 3D-Mosaics: A Hybrid Framework for Photorealistic Walkthroughs of Large Natural Environments

2008 ◽  
Vol 2008 ◽  
pp. 1-17
Author(s):  
Nikos Komodakis ◽  
Georgios Tziritas
Keyword(s):  
Natural Environments ◽  
Large Complex ◽  
Outdoor Scenes ◽  
Hybrid Framework ◽  
Interactive Frame ◽  
Visual Reconstruction ◽  
Sparse Set ◽  
3D Mosaics

This paper presents a hybrid (geometry- & image-based) framework suitable for providing photorealistic walkthroughs of large, complex outdoor scenes at interactive frame rates. To this end, based just on a sparse set of real stereoscopic views from the scene, a set ofmorphable 3D-mosaicsis automatically constructed first, and then, during rendering, a continuous morphing between those 3D-mosaics that are nearby to the current viewpoint is taking place. The morphing is both photometric, as well as geometric, while we also ensure that it proceeds in a physically valid manner, thus remaining transparent to the user. The effectiveness of our framework has been demonstrated in the 3D visual reconstruction of the Samaria Gorge in Crete, which is one of the largest and most beautiful gorges in Europe.

scholarly journals Hyperspectral environmental illumination maps: Characterizing directional spectral variation in natural environments

2019 ◽  
Author(s):  
Takuma Morimoto ◽  
Sho Kishigami ◽  
João M.M. Linhares ◽  
Sérgio M.C. Nascimento ◽  
Hannah E. Smithson
Keyword(s):  
Imaging System ◽  
Incident Angle ◽  
Incident Light ◽  
Natural Environments ◽  
Spectral Variation ◽  
Spectral Content ◽  
Outdoor Scenes ◽  
Directional Variation ◽  
Indoor Scenes ◽  
Spectral Channels

AbstractObjects placed in real-world scenes receive incident light from every direction, and the spectral content of this light may vary from one direction to another. In computer graphics, environmental illumination is approximated using maps that specify illumination at a point as a function of incident angle. However, to-date, existing public databases of environmental illumination maps specify only three colour channels (RGB). We have captured a new set of 12 environmental illumination maps (eight outdoor scenes; four indoor scenes) using a hyperspectral imaging system with 33 spectral channels. The data reveal a striking directional variation of spectral distribution of lighting in natural environments. We discuss limitations of using daylight models to describe natural environmental illumination.

scholarly journals Ecologically Sound Procedural Generation of Natural Environments

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Benny Onrust ◽  
Rafael Bidarra ◽  
Robert Rooseboom ◽  
Johan van de Koppel
Keyword(s):  
Virtual Worlds ◽  
Statistical Data ◽  
Plant Distribution ◽  
Natural Environments ◽  
Ecological Data ◽  
Vegetation Model ◽  
Web Based ◽  
Procedural Generation ◽  
Interactive Visualizations ◽  
Interactive Frame

Current techniques for the creation and exploration of virtual worlds are largely unable to generate sound natural environments from ecological data and to provide interactive web-based visualizations of such detailed environments. We tackle this challenge and propose a novel framework that (i) explores the advantages of landscape maps and ecological statistical data, translating them to an ecologically sound plant distribution, and (ii) creates a visually convincing 3D representation of the natural environment suitable for its interactive visualization over the web. Our vegetation model improves techniques from procedural ecosystem generation and neutral landscape modeling. It is able to generate diverse ecological sound plant distributions directly from landscape maps with statistical ecological data. Our visualization model integrates existing level of detail and illumination techniques to achieve interactive frame rates and improve realism. We validated with ecology experts the outcome of our framework using two case studies and concluded that it provides convincing interactive visualizations of large natural environments.

Effect of Iron Limitation on the Ultrastructure of Agmenellum Quadruplicatum

1981 ◽  
Vol 39 ◽  
pp. 410-411
Author(s):  
L. P. Hardie ◽  
D. L. Balkwill ◽  
S. E. Stevens
Keyword(s):  
Growth Medium ◽  
Green Alga ◽  
Natural Habitat ◽  
Iron Limitation ◽  
Natural Environments ◽  
Blue Green Alga ◽  
Marine Cyanobacterium ◽  
Natural Systems ◽  
Thin Sectioning ◽  
Agmenellum Quadruplicatum

Agmenellum quadruplicatum is a unicellular, non-nitrogen-fixing, marine cyanobacterium (blue-green alga). The ultrastructure of this organism, when grown in the laboratory with all necessary nutrients, has been characterized thoroughly. In contrast, little is known of its ultrastructure in the specific nutrient-limiting conditions typical of its natural habitat. Iron is one of the nutrients likely to limit this organism in such natural environments. It is also of great importance metabolically, being required for both photosynthesis and assimilation of nitrate. The purpose of this study was to assess the effects (if any) of iron limitation on the ultrastructure of A. quadruplicatum. It was part of a broader endeavor to elucidate the ultrastructure of cyanobacteria in natural systemsActively growing cells were placed in a growth medium containing 1% of its usual iron. The cultures were then sampled periodically for 10 days and prepared for thin sectioning TEM to assess the effects of iron limitation.

Using Personal Cell Phones for Ecological Momentary Assessment

2013 ◽  
Vol 18 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Emmanuel Kuntsche ◽  
Florian Labhart
Keyword(s):  
Data Collection ◽  
Ecological Momentary Assessment ◽  
Communication Systems ◽  
Cell Phones ◽  
Personal Digital Assistants ◽  
Natural Environments ◽  
Mobility Patterns ◽  
Standard Data ◽  
Ecological Momentary ◽  
Momentary Assessment

Ecological Momentary Assessment (EMA) is a way of collecting data in people’s natural environments in real time and has become very popular in social and health sciences. The emergence of personal digital assistants has led to more complex and sophisticated EMA protocols but has also highlighted some important drawbacks. Modern cell phones combine the functionalities of advanced communication systems with those of a handheld computer and offer various additional features to capture and record sound, pictures, locations, and movements. Moreover, most people own a cell phone, are familiar with the different functions, and always carry it with them. This paper describes ways in which cell phones have been used for data collection purposes in the field of social sciences. This includes automated data capture techniques, for example, geolocation for the study of mobility patterns and the use of external sensors for remote health-monitoring research. The paper also describes cell phones as efficient and user-friendly tools for prompt manual data collection, that is, by asking participants to produce or to provide data. This can either be done by means of dedicated applications or by simply using the web browser. We conclude that cell phones offer a variety of advantages and have a great deal of potential for innovative research designs, suggesting they will be among the standard data collection devices for EMA in the coming years.

Assessing flood risk and detecting changes of salt water inflow in a coastal micro-tidal brackish marsh using GIS

2008 ◽  
Vol 37 (3) ◽  
Author(s):  
Jacek Urbański ◽  
Agata Ślimak
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Flood Risk ◽  
Salt Water ◽  
Brackish Marsh ◽  
Distance Functions ◽  
Water Inflow ◽  
Small Range ◽  
Natural Environments ◽  
Baltic Coast

Assessing flood risk and detecting changes of salt water inflow in a coastal micro-tidal brackish marsh using GISIn order to assess changes in salt water inflow and potential flood risks due to sea level rise in a micro-tidal Beka brackish marsh on the Polish Baltic Coast GIS was used. Such wetlands are important elements of coastal zone natural environments. Creating a geodatabase within a GIS system makes it possible to carry out broad analyses of complex systems, such as coastal wetlands. The results indicate that a 40 cm sea-level rise would considerably increase the frequency of flooding in the investigated area, in part because of the small range of the annual sea level oscillations there. A map of the index of changes in saltwater inflow, created with the help of cost-weighted distance (functions), shows that changes which have occurred along the shore, consisting of filling in the drainage channel outlets, have likely had a significant impact on the vegetation of the area.

Aesthetic and Historical Values - Their Difference and Why It Matters

2020 ◽  
Vol 29 (5) ◽  
pp. 519-535
Author(s):  
Levi Tenen
Keyword(s):  
Natural Environments ◽  
Aesthetic Value ◽  
Environmental Preservation ◽  
Historical Significance ◽  
Recent Scholarship ◽  
In Virtue Of

Aesthetic and historical values are commonly distinguished from each other. Yet there has not been sustained discussion of what, precisely, differs between them. In fact, recent scholarship has focused on various ways in which the two are related. I argue, though, that historical value can differ in an interesting way from aesthetic value and that this difference may have significant implications for environmental preservation. In valuing something for its historical significance, it need not always be the case that there is a reason to want people to experience the entity. Valuing something for its aesthetic merit, by contrast, does imply a reason to want people to experience the entity. I suggest that in virtue of this difference, some historical values may offer better justification for preserving natural environments than do aesthetic considerations.

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