AUTOMATIC PAPER SLICEFORM DESIGN FROM 3D SOLID MODELS

Master'sMASTER OF SCIENC

Composition of texture atlases for 3D mesh multi-texturing

We introduce an automatic technique for mapping onto a 3D triangle mesh, approximating the shape of a real 3D object, a high resolution texture synthesized from several pictures taken simultaneously by real cameras surrounding the object. We create a texture atlas by first unwrapping the 3D mesh to form a set of 2D patches with no distortion (i.e., the angles and relative sizes of the 3D triangles are preserved in the atlas), and then mixing the color information from the input images, through another three steps: step no. 2 packs the 2D patches so that the bounding canvas of the set is as small as possible; step no. 3 assigns at most one triangle to each canvas pixel; finally, in step no. 4, the color of each pixel is calculated as a smoothly varying weighted average of the corresponding pixels from several input photographs. Our method is especially good for the creation of realistic 3D models without the need of having graphic artists retouch the texture. Categories and Subject Descriptors (according to ACM CCS): Computer Graphics [1.3.7]: Three-Dimensional Graphics and Realism—Color, shading, shadowing, and textur

Enabling New Functionally Embedded Mechanical Systems Via Cutting, Folding, and 3D Printing

Traditional design tools and fabrication methods implicitly prevent mechanical engineers from encapsulating full functionalities such as mobility, transformation, sensing and actuation in the early design concept prototyping stage. Therefore, designers are forced to design, fabricate and assemble individual parts similar to conventional manufacturing, and iteratively create additional functionalities. This results in relatively high design iteration times and complex assembly strategies

State of the Art on Stylized Fabrication

© 2018 The Authors Computer Graphics Forum © 2018 The Eurographics Association and John Wiley & Sons Ltd. Digital fabrication devices are powerful tools for creating tangible reproductions of 3D digital models. Most available printing technologies aim at producing an accurate copy of a tridimensional shape. However, fabrication technologies can also be used to create a stylistic representation of a digital shape. We refer to this class of methods as ‘stylized fabrication methods’. These methods abstract geometric and physical features of a given shape to create an unconventional representation, to produce an optical illusion or to devise a particular interaction with the fabricated model. In this state-of-the-art report, we classify and overview this broad and emerging class of approaches and also propose possible directions for future research

FOSTRAD : An advanced open source tool for re-entry analysis

This work responds to the need of modeling the atmospheric re-entry of space debris, satellites, and spacecraft quickly, efficiently and with a reasonable reliability. The Free Open Source Tool for Re-entry of Asteroids and Debris (FOSTRAD) is a simulation suite that allows for the estimation of aerodynamics and aerothermodynamics of an entry object in a continuum or rarefied hypersonic flow by employing the local panel formulation. In this paper, the work done to integrate the tool within a comprehensive framework allowing the simulation of complex geometries using a mesh handler module, a 3DOF trajectory propagator, and a surrogate model generation function, is presented. In addition, a synchronous coupling with a 1D thermal ablation code has been implemented and tested. The mesh module allows operations such as surface local radius computation, surface facets visibility identification, and objects geometrical evolution due to the burn-up during the re-entry. In the continuum regime, the simplified aerothermodynamics are computed using a local radius formulation, while the tool employs a flat-plate based approach in the free molecular regime. A generalized nose radius-based bridging model has been introduced for the rarefied transitional regime. The tests have demonstrated that applying a local radius formulation along with the radius-based bridging model greatly improves the accuracy of re-entry heat-flux estimations. The integrated framework has been tested on two different examples of atmospheric re-entries: the ESA Intermediate Experimental Vehicle (IXV) trajectory optimization and the Stardust sample return capsule Thermal Protection System (TPS) burn-up recession; and the coupling between FOSTRAD and the thermal ablation code allowed to study a step-by-step trajectory evolution of Stardust TPS. The obtained results show good agreement with the literature

Graph Rotation Systems for Physical Construction of Large Structures

In this dissertation, I present an approach for physical construction of large structures. The approach is based on the graph rotation system framework. I propose two kinds of physical structures to represent the shape of design models. I have developed techniques to generate developable panels from any input polygonal mesh, which can be easily assembled to get the shape of the input polygonal mesh. The first structure is called plain woven structures. I have developed the ?projection method? to convert mathematical weaving cycles on any given polygonal mesh to developable strip panels. The width of weaving strips varies so that the surface of the input model can be covered almost completely. When these strip panels are assembled together, resulting shape resembles to a weaving in 3-space. The second structure is called band decomposition structures. I have developed a method to convert any given polygonal mesh into star-like developable elements, which we call vertex panels. Assembling vertex panels results in band decomposition structures. These band decomposition structures correspond to 2D-thickening of graphs embedded on surfaces. These band decompositions are contractible to their original graph. In a 2D-thickening, each vertex thickens to a polygon and each edge thickens to a band. Within the resulting band decomposition, each polygon corresponds to a vertex and each band corresponds to an edge that connects two vertex polygons. Since the approach is based on graph rotation system framework, the two structures do not have restrictions on design models. The input mesh can be of any genus. The faces in the input mesh can be triangle, quadrilateral, and any polygon. The advantages of this kind of large physical structure construction are low-cost material and prefabrication, easy assemble. Our techniques take the digital fabrication in a new direction and create complex and organic 3D forms. Along the theme of architecture this research has great implication for structure design and makes the more difficult task of construction techniques easier to understand for the fabricator. It has implications to the sculpture world as well as architecture

Proceedings of the Second PHANToM Users Group Workshop : October 19-22, 1997 : Endicott House, Dedham, MA, Massachusetts Institute of Technology, Cambridge, MA

"December, 1997." Cover title.Includes bibliographical references.Sponsored by SensAble Technologies, Inc., Cambridge, MA."[edited by J. Kennedy Salisbury and Mandayam A. Srinivasan]