Adjunct senior researcher
Publications
2014
![[PDF]](https://vis.uib.no/wp-content/plugins/papercite/img/pdf.png)
[Bibtex] @ARTICLE {Natali14Rapid,
author = "Mattia Natali and Julius Parulek and Daniel Patel",
title = "Rapid Modelling of Interactive Geological Illustrations with Faults and Compaction",
journal = "Proceedings of Spring Conference on Computer Graphics (SCCG)",
year = "2014",
abstract = "In this paper, we propose new methods for building geological illustrations and animations. We focus on allowing geologists to create their subsurface models by means of sketches, to quickly communicate concepts and ideas rather than detailed information. The result of our sketch-based modelling approach is a layer-cake volume representing geological phenomena, where each layer is rock material which has accumulated due to a user-defined depositional event. Internal geological structures can be inspected by different visualization techniques that we employ. Faulting and compaction of rock layers are important processes in geology. They can be modelled and visualized with our technique. Our representation supports non-planar faults that a user may define by means of sketches. Real-time illustrative animations are achieved by our GPU accelerated approach.",
pdf = "pdfs/Natali14Rapid.pdf",
images = "images/Natali2014Rapid0.png, images/Natali2014Rapid1.png",
thumbnails = "images/Natali2014Rapid0.png, images/Natali2014Rapid1.png",
url = "http://dx.doi.org/10.1145/2643188.2643201",
project = "geoillustrator"
}![[DOI]](https://vis.uib.no/wp-content/plugins/papercite/img/external.png){kind=small}
![[VID]](https://vis.uib.no/wp-content/papercite-data/images/video.png)
[Bibtex] @ARTICLE {Natali14Sketch,
author = "Mattia Natali and Tore Grane Klausen and Daniel Patel",
title = "Sketch-Based Modelling and Visualization of Geological Deposition",
journal = "Computers \& Geosciences",
year = "2014",
volume = "67C",
pages = "40--48",
abstract = "We propose a method for sketching and visualizing geological models by sequentially defining stratigraphic layers, where each layer represents a unique erosion or deposition event. Evolution of rivers and deltas is important for geologists when interpreting the stratigraphy of the subsurface, in particular for hydrocarbon exploration. We illustratively visualize mountains, basins, lakes, rivers and deltas, and how they change the morphology of a terrain during their evolution. We present a compact representation of the model and a novel rendering algorithm that allows us to obtain an interactive and illustrative layer-cake visualization. A user study has been performed to evaluate our method.",
vid = "vids/Natali2014Sketch.mp4",
images = "images/Natali2014Sketch0.png, images/Natali2014Sketch1.png",
thumbnails = "images/Natali2014Sketch0.png, images/Natali2014Sketch1.png",
doi = "10.1016/j.cageo.2014.02.010",
url = "http://www.sciencedirect.com/science/article/pii/S0098300414000508",
project = "geoillustrator"
}2013
[Bibtex] @ARTICLE {Lidal13Geological,
author = "Endre M. Lidal and Mattia Natali and Daniel Patel and Helwig Hauser and Ivan Viola",
title = "Geological storytelling",
journal = "Computers \& Graphics",
year = "2013",
volume = "37",
number = "5",
pages = "445--459 ",
abstract = "Developing structural geological models from exploratory subsea imaging is difficult and an ill-posed process. The structural geological processes that take place in the subsurface are both complex and time-dependent. We present Geological Storytelling, a novel graphical system for performing rapid and expressive geomodeling. Geologists can convey geological stories that externalize both their model and the reasoning process behind it through our simple, yet expressive sketch-based, flip-over canvases. This rapid modeling interface makes it easy to construct a large variety of geological stories, and our story tree concept facilitates easy management and the exploration of these alternatives. The stories are then animated and the geologists can examine and compare them to identify the most plausible models. Finally, the geological stories can be presented as illustrative animations of automatically synthesized 3D models, which efficiently communicate the complex geological evolution to non-experts and decision makers. Geological storytelling provides a complete pipeline from the ideas and knowledge in the mind of the geologist, through externalized artifacts specialized for discussion and knowledge dissemination among peer-experts, to automatically rendered illustrative 3D animations for communication to lay audience. We have developed geological storytelling in collaboration with domain experts that work with the modeling challenges on a daily basis. For evaluation, we have developed a geological storytelling prototype and presented it to experts and academics from the geosciences. In their feedback, they acknowledge that the rapid and expressive sketching of stories can make them explore more alternatives and that the 3D illustrative animations assist in communicating their models.",
images = "images/Lidal13Geological01.jpg, images/Lidal13Geological02.png",
thumbnails = "images/Lidal13Geological01.jpg, images/Lidal13Geological02.png",
issn = "0097-8493",
doi = "http://dx.doi.org/10.1016/j.cag.2013.01.010",
url = "http://www.sciencedirect.com/science/article/pii/S0097849313000125",
keywords = "Sketch-based modeling; Externalization of mental processes; Storytelling; 3D model synthesis; Animation; Alternatives exploration; Geology; Structural geological models",
project = "geoillustrator"
}@INPROCEEDINGS {Natali13Modeling,
author = "Mattia Natali and Endre M. Lidal and Julius Parulek and Ivan Viola and Daniel Patel",
title = "Modeling Terrains and Subsurface Geology",
booktitle = "EuroGraphics 2013 State of the Art Reports (STARs)",
year = "2013",
pages = "155--173",
abstract = "The process of creating terrain and landscape models is important in a variety of computer graphics and visualization applications, from films and computer games, via flight simulators and landscape planning, to scientific visualization and subsurface modelling. Interestingly, the modelling techniques used in this large range of application areas have started to meet in the last years. In this state-of-the-art report, we present two taxonomies of different modelling methods. Firstly we present a data oriented taxonomy, where we divide modelling into three different scenarios: the data-free, the sparse-data and the dense-data scenario. Then we present a workflow oriented taxonomy, where we divide modelling into the separate stages necessary for creating a geological model. We start the report by showing that the new trends in geological modelling are approaching the modelling methods that have been developed in computer graphics. We then give an introduction to the process of geological modelling followed by our two taxonomies with descriptions and comparisons of selected methods. Finally we discuss the challenges and trends in geological modelling.",
pdf = "pdfs/Natali13Modeling.pdf",
images = "images/Natali13Modeling.png",
thumbnails = "images/Natali13Modeling.png",
proceedings = "EuroGraphics 2013 State of the Art Reports (STARs)",
url = "http://diglib.eg.org/EG/DL/conf/EG2013/stars/155-173.pdf",
doi = "10.2312/conf/EG2013/stars/155-173",
location = "Girona, Spain",
project = "geoillustrator"
}![[YT]](https://vis.uib.no/wp-content/papercite-data/images/youtube.png)
[Bibtex] @ARTICLE {Patel-2013-ICS,
author = "Daniel Patel and Veronika \v{S}olt{\'e}szov{\'a} and Jan Martin Nordbotten and Stefan Bruckner",
title = "Instant Convolution Shadows for Volumetric Detail Mapping",
journal = "ACM Transactions on Graphics",
year = "2013",
volume = "32",
number = "5",
pages = "154:1--154:18",
month = "sep",
abstract = "In this article, we present a method for rendering dynamic scenes featuring translucent procedural volumetric detail with all-frequency soft shadows being cast from objects residing inside the view frustum. Our approach is based on an approximation of physically correct shadows from distant Gaussian area light sources positioned behind the view plane, using iterative convolution. We present a theoretical and empirical analysis of this model and propose an efficient class of convolution kernels which provide high quality at interactive frame rates. Our GPU-based implementation supports arbitrary volumetric detail maps, requires no precomputation, and therefore allows for real-time modi?cation of all rendering parameters.",
pdf = "pdfs/Patel-2013-ICS.pdf",
images = "images/Patel-2013-ICS.jpg",
thumbnails = "images/Patel-2013-ICS.png",
youtube = "https://www.youtube.com/watch?v=lhGWgew3HXY,https://www.youtube.com/watch?v=XrhYjgQxfb0",
doi = "10.1145/2492684",
keywords = "shadows, volumetric effects, procedural texturing, filtering",
project = "geoillustrator",
url = "http://dl.acm.org/citation.cfm?id=2492684"
}@INPROCEEDINGS {Lidal13Rapid,
author = "Endre Lidal and Daniel Patel and Morten Bendiksen and Tor Langeland and Ivan Viola",
title = "Rapid Sketch-based 3D Modeling of Geology",
booktitle = "Proceedings of EnvirVis Short Papers 2013",
year = "2013",
abstract = "We present and compare two different approaches for performing rapid 3D geological modeling. The ad-hoc approach is based on a composition of many specialized modeling functions, while the generic approach provides one powerful, generic modeling function. Our experiences after developing these two approaches are that the solution space of 3D geological modeling is more extensive than we initially expected and most likely larger than for other modeling domains such as architecture. Further, more research is needed to investigate whether it is possible to �nd one well de�ned toolset of sketching metaphors that is able to cover all of geological modeling.",
pdf = "pdfs/Lidal13Rapid.pdf",
images = "images/Lidal13Rapid01.png",
thumbnails = "images/Lidal13Rapid01_thumb.png",
project = "geoillustrator"
}2012
[Bibtex] @INPROCEEDINGS {Solteszova12Stylized,
author = "Veronika \v{S}olt{\'e}szov{\'a} and Ruben Patel and Helwig Hauser and Ivanko Viola",
title = "Stylized Volume Visualization of Streamed Sonar Data",
booktitle = "Proceedings of Spring Conference on Computer Graphics (SCCG 2012)",
year = "2012",
pages = "13--20",
month = "May",
abstract = "Current visualization technology implemented in the software for 2D sonars used in marine research is limited to slicing whilst volume visualization is only possible as post processing. We designed and implemented a system which allows for instantaneous volume visualization of streamed scans from 2D sonars without prior resampling to a voxel grid. The volume is formed by a set of most recent scans which are being stored. We transform each scan using its associated transformations to the view-space and slice their bounding box by view-aligned planes. Each slicing plane is reconstructed from the underlying scans and directly used for slice-based volume rendering. We integrated a low frequency illumination model which enhances the depth perception of noisy acoustic measurements. While we visualize the 2D data and time as 3D volumes, the temporal dimension is not intuitively communicated. Therefore, we introduce a concept of temporal outlines. Our system is a result of an interdisciplinary collaboration between visualization and marine scientists. The application of our system was evaluated by independent domain experts who were not involved in the design process in order to determine real life applicability.",
pdf = "pdfs/Solteszova12Stylized.pdf",
vid = "vids/Solteszova12Stylized.mp4",
images = "images/Solteszova12Stylized01.png, images/Solteszova12Stylized02.png, images/Solteszova12Stylized03.png",
thumbnails = "images/Solteszova12Stylized01_thumb.png, images/Solteszova12Stylized02_thumb.png, images/Solteszova12Stylized03_thumb.png",
note = "Second best paper and second best presentation awards",
location = "Smolenice castle, Slovakia",
project = "illustrasound,medviz,illvis"
}@INPROCEEDINGS {Natali12Rapid,
author = "Mattia Natali and Ivan Viola and Daniel Patel",
title = "Rapid Visualization of Geological Concepts",
booktitle = "SIBGRAPI 2012 (XXV Conference on Graphics, Patterns and Images)",
year = "2012",
editor = "C. Freitas, L. Silva, R. Scopigno, and S. Sarkar",
address = "Ouro Preto, MG, Brazil",
month = "August",
abstract = "We describe a sketch-based system for constructing an illustrative visualization of the subsurface. An intuitive and rapid modelling tool is defined, which takes as input user's strokes and creates a 3D layer-cake model of the earth. Our tool enables users to quickly express and communicate their ideas directly using a 3D model. For sketching, we have created geometric operators that capture the domain specific modelling requirements.We have devised sketching operators for expressing folding and faulting processes. This makes it possible to produce a large span of scenarios. Moreover, for communicating layer properties such as rock type and grain size, our system allows for associating user defined texture to each layer which can be deformed with a few sketch strokes.",
images = "images/Natali12Rapid01.png, images/Natali12Rapid02.png",
thumbnails = "images/Natali12Rapid01_thumb.png, images/Natali12Rapid02_thumb.png",
url = "http://www.decom.ufop.br/sibgrapi2012/",
doi = "10.1109/SIBGRAPI.2012.29",
project = "geoillustrator"
}