16 research outputs found
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Functionally Gradient Material Design and Modeling Using Hypertexture for Solid Freeform Fabrication
SFF technologies have the potential to become manufacturing process that are capable of producing
parts that have not been feasible by other techniques. The fabrication of Functionally Gradient Material
(FGM) is one of the possible candidate. It is critical.to provide three dimensional material gradient data
in the solid model to fabricate FGM. The approach is to model spatially varying material density
distribution on implicit solid geometry using a hypertexturing scheme and a procedural volumetric
modeling. It is essentially an extension of procedural solid texture synthesis, which has been effectively
used to model cloud, gas, and flow stream. It will save the amount of information storage especially
when the gradient pattern is repeating. Geometric operation becomes convenient since the material data
are linked to the geometry only by the reference surfaces.Mechanical Engineerin
A Library for Declarative Resolution-Independent 2D Graphics
The design of most 2D graphics frameworks has been guided by what the computer can draw efficiently, instead of by how graphics can best be expressed and composed. As a result, such frameworks restrict expressivity by providing a limited set of shape primitives, a limited set of textures and only affine transformations. For example, non-affine transformations can only be added by invasive modification or complex tricks rather than by simple composition. More general frameworks exist, but they make it harder to describe and analyze shapes. We present a new declarative approach to resolution-independent 2D graphics that generalizes and simplifies the functionality of traditional frameworks, while preserving their efficiency. As a real-world example, we show the implementation of a form of focus+context lenses that gives better image quality and better performance than the state-of-the-art solution at a fraction of the code. Our approach can serve as a versatile foundation for the creation of advanced graphics and higher level frameworks
A theoretical reflection on smart shape modeling
This paper presents, as far as the authors are aware, a complete and extended new taxonomy of shape specification modeling techniques and a characterization of shape design systems, all based on the relationship of usersâ knowledge to the modeling system they use to generate shapes. In-depth knowledge of this relationship is not usually revealed in the regular university training courses such as bachelorâs, masterâs and continuing education. For this reason, we believe that it is necessary to modify the learning process, offering a more global vision of all the currently existing techniques and extending training in those related to algorithmic modeling techniques. We consider the latter to be the most powerful current techniques for modeling complex shapes that cannot be modeled with the usual techniques known to date. Therefore, the most complete training should include everything from the usual geometry to textual programming. This would take us a step further along the way to more powerful design environments. The proposed taxonomy could serve as a guideline to help improve the learning process of students and designers in a complex environment with increasingly powerful requirements and tools. The term âsmartâ is widely used nowadays, e.g. smart phones, smart cars, smart homes, smart cities... and similar terms such as âsmart shape modelingâ. Nowadays, the term smart is applied from a marketing point of view, whenever an innovation is used to solve a complex problem. This is the case for what is currently called smart shape modeling. However, in the future; this concept should mean a much better design environment than today. The smart future requires better trained and skilled engineers, architects, designers or technical students. This means that they must be prepared to be able to contribute to the creation of new knowledge, to the use of innovations to solve complex problems of form, and to the extraction of the relevant pieces of intelligence from the growing volume of knowledge and technologies accessible today. Our taxonomy is presented from the point of view of methods that are possibly furthest away from what is considered today as âintelligent shape modelingâ to the limit of what is achievable today and which the authors call âGeneric Shape Algorithmâ. Finally, we discuss the characteristics that a shape modeling system must have to be truly âintelligentâ: it must be âproactiveâ in applying innovative ideas to achieve a solution to a complex problem
Intersecting biquadratic BĂ©zier surface patches
International audienceWe present three symbolicânumeric techniques for computing the in- tersection and selfâintersection curve(s) of two BĂ©zier surface patches of bidegree (2,2). In particular, we discuss algorithms, implementation, illustrative examples and provide a comparison of the methods
A Library for Declarative Resolution-Independent 2D Graphics
htmlabstractThe design of most 2D graphics frameworks has been guided by what the computer can draw efficiently, instead of by how graphics can best be expressed and composed. As a result, such frameworks restrict expressivity by providing a limited set of shape primitives, a limited set of textures and only affine transformations. For example, non-affine transformations can only be added by invasive modification or complex tricks rather than by simple composition. More general frameworks exist, but they make it harder to describe and analyze shapes. We present a new declarative approach to resolution-independent 2D graphics that generalizes and simplifies the functionality of traditional frameworks, while preserving their efficiency. As a real-world example, we show the implementation of a form of focus+context lenses that gives better image quality and better performance than the state-of-the-art solution at a fraction of the code. Our approach can serve as a versatile foundation for the creation of advanced graphics and higher level frameworks
Intersecting biquadratic BĂ©zier surface patches
International audienceWe present three symbolicânumeric techniques for computing the in- tersection and selfâintersection curve(s) of two BĂ©zier surface patches of bidegree (2,2). In particular, we discuss algorithms, implementation, illustrative examples and provide a comparison of the methods