@article{birsak-2017-dpe, title = "Dynamic Path Exploration on Mobile Devices", author = "Michael Birsak and Przemyslaw Musialski and Peter Wonka and Michael Wimmer", year = "2018", abstract = "We present a novel framework for visualizing routes on mobile devices. Our framework is suitable for helping users explore their environment. First, given a starting point and a maximum route length, the system retrieves nearby points of interest (POIs). Second, we automatically compute an attractive walking path through the environment trying to pass by as many highly ranked POIs as possible. Third, we automatically compute a route visualization that shows the current user position, POI locations via pins, and detail lenses for more information about the POIs. The visualization is an animation of an orthographic map view that follows the current user position. We propose an optimization based on a binary integer program (BIP) that models multiple requirements for an effective placement of detail lenses. We show that our path computation method outperforms recently proposed methods and we evaluate the overall impact of our framework in two user studies.", month = may, doi = "10.1109/TVCG.2017.2690294", issn = "1077-2626", journal = "IEEE Transactions on Visualization and Computer Graphics", number = "5", volume = "24", pages = "1784--1798", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/birsak-2017-dpe/", } @article{Birsak2018-SA, title = "String Art: Towards Computational Fabrication of String Images", author = "Michael Birsak and Florian Rist and Peter Wonka and Przemyslaw Musialski", year = "2018", abstract = "In this paper we propose a novel method for the automatic computation and digital fabrication of artistic string images. String art is a technique used by artists for the creation of abstracted images which are composed of straight lines of strings ten- sioned between pins distributed on a frame. Together the strings fuse to a perceptible image. Traditionally, artists craft such images manually in a highly sophisticated and tedious design process. To achieve this goal fully automatically we propose a computational setup driven by a discrete optimization algorithm which takes an ordinary picture as input and converts it into a connected graph of strings that tries to reassemble the input image best possibly. Furthermore, we propose a hardware setup for automatic digital fabrication of these images using an industrial robot that spans the strings. Finally, we demonstrate the applicability of our approach by generating and fabricating a set of real string art images.", month = apr, journal = "Computer Graphics Forum (Proc. EUROGRAPHICS 2018)", volume = "37", number = "2", doi = "10.1111/cgf.13359", pages = "accepted", pages = "263--274", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/Birsak2018-SA/", } @bachelorsthesis{gersthofer-2016-sosob, title = "Reduced-Order Shape Optimization Using Offset Surfaces in Blender", author = "Lukas Gersthofer", year = "2018", abstract = "The advance of 3D printers’ capabilities and their sinking costs led to a huge trend of personal and commercial fabrication. But those advances were restricted to the hardware side meaning that there was a lack of software to optimize the digital models before printing. This was necessary because physical properties like mass, center of mass or moments of inertia, were neglected in the design of digital 3D models. Those properties play an important role in the behavior of a real-world object. Examples of an objects behavior are the ability to stand in a specific pose, float in the water or stably rotate around a certain axis. In the last few years methods have been presented to optimize digital models by altering specific regions of their volume in order to change their physical properties and therefore to prepare them for printing. A recently presented method forms the basis of this thesis. Due to its flexibility and performance it is well suited to be integrated into current 3D modeling applications. The algorithm was implemented as a C/C++ library which can be integrated in almost every application. Afterwards this library was integrated into the open source 3D modeling application Blender as a modifier. ", month = feb, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "geometry processing, shape optimization, blender plugin", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/gersthofer-2016-sosob/", } @article{leimer_2017_rbpesc, title = "Relation-Based Parametrization and Exploration of Shape Collections", author = "Kurt Leimer and Lukas Gersthofer and Michael Wimmer and Przemyslaw Musialski", year = "2017", abstract = "With online repositories for 3D models like 3D Warehouse becoming more prevalent and growing ever larger, new possibilities have emerged for both experienced and inexperienced users. These large collections of shapes can provide inspiration for designers or make it possible to synthesize new shapes by combining different parts from already existing shapes, which can be both easy to learn and a fast way of creating new shapes. But exploring large shape collections or searching for particular kinds of shapes can be difficult and time-consuming tasks as well, especially considering that online repositories are often disorganized. In our work, we propose a relation-based way to parametrize shape collections, allowing the user to explore the entire set of shapes based on the variability of spatial arrangements between pairs of parts. The way in which shapes differ from each other is captured automatically, resulting in a small number of exploration parameters. Furthermore, a copy-and-paste system for parts allows the user to change the structure of a shape, making it possible to explore the entire collection from any initial shape.", month = oct, issn = "0097-8493", journal = "Computers & Graphics", volume = "67", pages = "127--137", keywords = "3d database exploration, Model variability, Shape analysis, Shape collections", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/leimer_2017_rbpesc/", } @bachelorsthesis{aichner-2016-sadf, title = "Interactive Shape-Aware Deformation of 3D Furniture Models", author = "Lea Aichner", year = "2016", abstract = "Resizing of 3D models can be very useful when creating new models or when reusing old ones. However, naive resizing can create serious visual artifacts which destroy the characteristics of an object. In this thesis an algorithm that protects the features of 3D models during resizing is introduced. It is specialized for furniture models because it should be applied to a furniture configurator. We observed that the distortion that occurs during scaling is not distributed uniformly across the object. Our algorithm automatically detects the vulnerable parts of a model and then stretches only the non- vulnerable ones. Furthermore, the algorithm takes into account that when scaling a mesh in a specific direction, the texture has to be adapted as well in order to prevent representation errors.", month = nov, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "geometry processing, shape modeling, shape-aware deformation", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/aichner-2016-sadf/", } @article{steiner_2016_isad, title = "Integrated Structural-Architectural Design for Interactive Planning", author = "Bernhard Steiner and Elham Mousavian and Fatemeh Mehdizadeh Saradj and Michael Wimmer and Przemyslaw Musialski", year = "2017", abstract = "Traditionally, building floorplans are designed by architects with their usability, functionality, and architectural aesthetics in mind, however, the structural properties of the distribution of load-bearing walls and columns are usually not taken into account at this stage. In this paper we propose a novel approach for the design of architectural floorplans by integrating structural layout analysis directly into the planning process. In order to achieve this, we introduce a planning tool which interactively enforces checks for structural stability of the current design, and which on demand proposes how to stabilize it if necessary. Technically, our solution contains an interactive architectural modeling framework as well as a constrained optimization module where both are based on respective architectural rules. Using our tool, an architect can predict already in a very early planning stage which designs are structurally sound such that later changes due to stability reasons can be prevented. We compare manually computed solutions with optimal results of our proposed automated design process in order to show how much our proposed system can help architects to improve the process of laying out structural models optimally.", month = dec, doi = "10.1111/cgf.12996", issn = "1467-8659", journal = "Computer Graphics Forum", number = "8", volume = "36", pages = "80--94", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/steiner_2016_isad/", } @misc{leimer-2016-rpe, title = "Relation-Based Parametrization and Exploration of Shape Collections", author = "Kurt Leimer and Michael Wimmer and Przemyslaw Musialski", year = "2016", abstract = "With online repositories for 3D models like 3D Warehouse becoming more prevalent and growing ever larger, new possibilities have opened up for both experienced and inexperienced users alike. These large collections of shapes can provide inspiration for designers or make it possible to synthesize new shapes by combining different parts from already existing shapes, which can be both easy to learn and a fast way of creating new shapes. But exploring large shape collections or searching for particular kinds of shapes can be difficult and time-consuming tasks as well, especially considering that online repositories are often disorganized. In our work, we propose a relation-based way to parametrize shape collections, allowing the user to explore the entire set of shapes by controlling a small number of parameters.", month = jul, publisher = "ACM", location = "Anaheim, CA, USA", isbn = "978-1-4503-4371-8", event = "ACM SIGGRAPH 2016", booktitle = "ACM SIGGRAPH 2016 Posters", Conference date = "Poster presented at ACM SIGGRAPH 2016 (2016-07-24--2016-07-28)", note = "34:1--34:1", pages = "34:1 – 34:1", keywords = "3D database exploration, shape analysis, shape collections", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/leimer-2016-rpe/", } @article{musialski_2016_sosp, title = "Non-Linear Shape Optimization Using Local Subspace Projections", author = "Przemyslaw Musialski and Christian Hafner and Florian Rist and Michael Birsak and Michael Wimmer and Leif Kobbelt", year = "2016", abstract = "In this paper we present a novel method for non-linear shape optimization of 3d objects given by their surface representation. Our method takes advantage of the fact that various shape properties of interest give rise to underdetermined design spaces implying the existence of many good solutions. Our algorithm exploits this by performing iterative projections of the problem to local subspaces where it can be solved much more efficiently using standard numerical routines. We demonstrate how this approach can be utilized for various shape optimization tasks using different shape parameterizations. In particular, we show how to efficiently optimize natural frequencies, mass properties, as well as the structural yield strength of a solid body. Our method is flexible, easy to implement, and very fast.", journal = "ACM Transactions on Graphics", volume = "35", number = "4", issn = "0730-0301", doi = "10.1145/2897824.2925886", pages = "87:1--87:13", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/musialski_2016_sosp/", } @mastersthesis{leimer-2016-coan, title = "Co-Analysis and Parameterization of 3D Shape Collections for Shape Synthesis", author = "Kurt Leimer", year = "2016", abstract = "With online model repositories growing larger every day, both experienced and inexperienced modelers are presented with new possibilities for content creation. One such possibility is the creation of new shapes by combining parts of already existing shapes. The advantages of this shape synthesis method are that it takes less time than traditional modeling approaches and that it can be used even by inexperienced users. This thesis introduces a framework for this type of shape synthesis that consists of four stages, incorporating a new way for parameterization and exploration of shape collections. Using a modular and extensible approach, the co-analysis stage groups parts of shapes into categories based on their function, creating a correspondence between parts of different shapes. By analyzing relations between pairs of parts and how their spatial arrangements vary across the collection, a small number of parameters is found in the parameterization stage. Starting with an initial shape, these parameters can then be used to browse the collection in the exploration stage, either by altering the parameters directly or by interacting with the shape itself. Finally, in the synthesis stage a new shape can be created by exchanging parts of the initial shape with corresponding parts of the shapes found during the exploration.", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "computer graphics, 3D shape segmentation, 3D shape co-analysis, 3D shape processing", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/leimer-2016-coan/", } @mastersthesis{hafner-2015-eigf, title = "Optimization of Natural Frequencies for Fabrication-Aware Shape Modeling", author = "Christian Hafner", year = "2015", abstract = "Given a target shape and a target frequency, we automatically synthesize shapes that exhibit this frequency as part of their natural spectrum while resembling the target shape as closely as possible. We propose three shape parametrization methods that afford meaningful degrees of freedom in the design of instruments such as marimbas and bells. The design space is based on the representation of a solid as the volume enclosed by an outer surface and an inner offset surface. In order to evaluate the natural frequency spectrum of a solid, we employ finite element modal analysis and evaluate the suitability of different element types. We propose a fabrication method for the production of optimized instruments by an amateur craftsperson using sand or rubber molds. The efficiency of our method is demonstrated by the production of a simple tin bell and a more complicated bell in the shape of a rabbit. We achieve agreement with the predicted pitch frequencies of 2.8% and 6% respectively. These physical results are supplemented by a number of computational results that explore the optimization of harmonic ratios and the influence of mesh resolution and mesh smoothness on the accuracy of the finite element model.", month = sep, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "physically based modeling, computer graphics, digital fabrication, 3D shape optmization, 3D shape processing", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/hafner-2015-eigf/", } @article{musialski-2015-souos, title = "Reduced-Order Shape Optimization Using Offset Surfaces", author = "Przemyslaw Musialski and Thomas Auzinger and Michael Birsak and Michael Wimmer and Leif Kobbelt", year = "2015", abstract = "Given the 2-manifold surface of a 3d object, we propose a novel method for the computation of an offset surface with varying thickness such that the solid volume between the surface and its offset satisfies a set of prescribed constraints and at the same time minimizes a given objective functional. Since the constraints as well as the objective functional can easily be adjusted to specific application requirements, our method provides a flexible and powerful tool for shape optimization. We use manifold harmonics to derive a reduced-order formulation of the optimization problem, which guarantees a smooth offset surface and speeds up the computation independently from the input mesh resolution without affecting the quality of the result. The constrained optimization problem can be solved in a numerically robust manner with commodity solvers. Furthermore, the method allows simultaneously optimizing an inner and an outer offset in order to increase the degrees of freedom. We demonstrate our method in a number of examples where we control the physical mass properties of rigid objects for the purpose of 3d printing. ", month = aug, journal = "ACM Transactions on Graphics (ACM SIGGRAPH 2015)", volume = "34", number = "4", issn = "0730-0301", doi = "10.1145/2766955", pages = "102:1--102:9", keywords = "reduced-order models, shape optimization, computational geometry, geometry processing, physical mass properties", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/musialski-2015-souos/", } @misc{hafner-2015-onff, title = "Optimization of Natural Frequencies for Fabrication-Aware Shape Modeling", author = "Christian Hafner and Przemyslaw Musialski and Thomas Auzinger and Michael Wimmer and Leif Kobbelt", year = "2015", abstract = "Given a target shape and a target frequency, we automatically synthesize a shape that exhibits this frequency as part of its natural spectrum, while resembling the target shape as closely as possible. We employ finite element modal analysis with thin-shell elements to accurately predict the acoustic behavior of 3d solids. Our optimization pipeline uses an input surface and automatically calculates an inner offset surface to describe a volumetric solid. The solid exhibits a sound with the desired pitch if fabricated from the targeted material. In order to validate our framework, we optimize the shape of a tin bell to exhibit a sound at 1760 Hz. We fabricate the bell by casting it from a mold and measure the frequency peaks in its natural ringing sound. The measured pitch agrees with our simulation to an accuracy of 2.5%. In contrast to previous method, we only use reference material parameters and require no manual tuning.", month = aug, publisher = "ACM", note = "Lecturer: P. Musialski", location = "Los Angeles, CA, USA", event = "ACM SIGGRAPH 2015", booktitle = "Proceedings of ACM SIGGRAPH 2015 Posters", Conference date = "Poster presented at ACM SIGGRAPH 2015 (2015-08-09--2015-08-13)", keywords = "natural frequencies, modal analysis, shape optimization", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/hafner-2015-onff/", } @talk{musialski-2015-ista, title = "Reduced-Order Shape Optimization Using Offset Surfaces", author = "Przemyslaw Musialski", year = "2015", abstract = "Given the 2-manifold surface of a 3d object, we propose a novel method for the computation of an offset surface with varying thickness such that the solid volume between the surface and its offset satisfies a set of prescribed constraints and at the same time minimizes a given objective functional. Since the constraints as well as the objective functional can easily be adjusted to specific application requirements, our method provides a flexible and powerful tool for shape optimization. We use manifold harmonics to derive a reduced-order formulation of the optimization problem, which guarantees a smooth offset surface and speeds up the computation independently from the input mesh resolution without affecting the quality of the result. The constrained optimization problem can be solved in a numerically robust manner with commodity solvers. Furthermore, the method allows simultaneously optimizing an inner and an outer offset in order to increase the degrees of freedom. We demonstrate our method in a number of examples where we control the physical mass properties of rigid objects for the purpose of 3d printing. Link: https://ist.ac.at/events/symposia-conferences/2015/siggraph-nano-ist-austria/date/433/", event = "SIGGRAPH Nano @ Institute of Science and Technology (IST), Austria", location = "Institute of Science and Technology (IST), Austria", keywords = "geometry processing, digital fabrication, shape optimization", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/musialski-2015-ista/", } @talk{musialski-2015-pixel, title = "Computational Design for Consumer-Level Fabrication", author = "Przemyslaw Musialski", year = "2015", abstract = "Digital fabrication is currently a rapidly emerging field in several science and engineering fields. Especially the technique of additive manufacturing (AM), commonly referred to as 3d printing, is a fast growing area. While this technology is in essence not new, the recent expiration of key patents for 3d-printing technology led to a break-through, which already also arrived at the consumer-level 3d-printers market. This development brings about novel requirements on digital model design. Traditional fields used to deal with digital manufacturing, like rapid prototyping, material sciences, or industrial engineering learned to deal with existing CAD-software in order to create digital content. However, the expansion of the digital fabrication technology into everybody’s homes and offices brings about the demand for novel paradigms of consumer-level computational design. This novel personal fabrication aims at bridging the gap between the still advancing digital domain and the “good old” physical world. In this talk I will give an overview of current development of such computational design in the field of computer graphics and provide details on an example application. Link: http://www.pixelvienna.com/10/event/talks#musialski", event = "PIXEL X - Annual Austrian Computer Graphics and Animation Conference, Vienna, Austria", location = "PIXEL X, TU Wien, Karlsplatz 1, Vienna, Austria", keywords = "digital fabrication, geometry processing, shape optimization, computational design", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/musialski-2015-pixel/", } @talk{musialski-2015-vrvis, title = "Shape Optimization for Consumer-Level 3D Printing", author = "Przemyslaw Musialski", year = "2015", abstract = "Traditionally, 3d modelling in computer graphics deals with the geometric and visual aspects of 3d shapes. On the other hand, due to the growing capabilities of personal digital fabrication technology and its spread into offices and homes, 3d models are increasingly entering the physical world. Therefore, the physical properties of 3d models come into focus. For example, 3d-printed models should be able to stand balanced in a desired pose without toppling over, or should react in certain ways when external forces are applied, like spinning the object. It is thus desirable to have methods that allow the user to specify the intended physical properties of an object in addition to its 3d geometry, and which automatically take these properties into account when generating a specification for a 3d printer. In this talk I will give an introduction to such computational design problems and introduce our novel method for shape optimization based on offset surfaces. Link: http://www.vrvis.at/research/events/vrvisforum/vrvisforum-123-29.10.2015", event = "VRVisForum #123", location = "VRVis, Techgate Vienna, Austria", keywords = "shape optimization, geometry processing, digital fabrication", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/musialski-2015-vrvis/", }