Interactive mesh editing techniques that preserve discrete differential properties are promising to support the design of mechanical parts such as automobile sheet metal panels. However, existing methods lack the ability to manipulate form-features and hard constraints, which are common in engineering applications. In product design, some regions on a 3D model are often required to precisely pr...

We present a new efficient collision-handling technique of free-form deformation (FFD) of an embedded surface. By adapting FFD, modeling deformation has been substantially simplified to make possible interactive rate animation of a deformable object even for a complex embedded mesh. However, the lack of effective collision detection and resolution schemes for an FFD-embedded surface hinders the...

the mechanical properties and microstructural developments of 321 stainless steel during thermomechanicalprocess were investigated. the repetitive cold rolling and subsequent annealing wereconducted to achieve nanocrystalline structure in an aisi 321 stainless steel. heavily cold rolling at−20°c was conducted to form martensite in metastable austenitic steel. the process was followed byannealin...

A multi-Poisson structure on a Lie algebra g provides a systematic way to construct completely integrable Hamiltonian systems on g expressed in Lax form ∂Xλ/∂t = [Xλ, Aλ] in the sense of the isospectral deformation, where Xλ, Aλ ∈ g depend rationally on the indeterminate λ called the spectral parameter. In this paper, a method for modifying the isospectral deformation equation to the Lax equati...

ÐFree-Form Deformation (FFD) is a versatile and efficient modeling technique which transforms an object by warping the surrounding space. The conventional user-interface is a lattice of movable control points but this tends to be cumbersome and counterintuitive. Directly Manipulated Free-Form Deformation (DMFFD) allows the user to drag object points directly and has proven useful in an interact...

Implicit surfaces offer many advantages for sketch-based modeling systems, such as blending, CSG, and a procedural object hierarchy. Free-form deformation (FFD) is also extremely useful in this context, however existing FFD approaches do not support implicit surface representations, and FFD lattice manipulation is time-consuming compared to sketch-based techniques. In this thesis, an FFD techni...

This paper addresses the designers’ activity and in particular the way designers express an object shape in 2D sketches through character lines. The tools currently available in commercial CAS/CAD systems to manipulate the digital models are still not sufficiently suited to support design. In this paper, we introduce the so-called Fully Free Form Deformation Features (δ-F), able to take into ac...

In this paper, we present a free-form deformation (FFD) approach to manipulate point-sampled surface. Our approach provides users the powerful free-form deformation directly on point-sampled surface. In the preprocessing, we use a robust extension of hierarchical clustering scheme to partition a point-sampled model into clusters, fit a moving least square (MLS) surface to each of them, and defi...

We present a gesture-based user interface to Free-Form Deformation (FFD). Traditional interfaces for FFD require the manipulation of individual points in a lattice of control vertices, a process which is both time-consuming and error-prone. In our system, the user can bend, twist, and stretch/squash the model as if it were a solid piece of clay without being unduly burdened by the mathematical ...

Understanding the mechanism of deformation is very important in various applications. Although the stress–strain behavior of crystals and glasses are similar, the mechanism of deformation is very different. We used molecular dynamics to study polycarbonate and polystyrene under constant external loads. The results indicate that high atomic/segmental mobility and low local density enable the for...