Wavelet SDF-Reps: Solid Modeling With Volumetric Scans

2009 ◽  
Vol 9 (3) ◽  
Author(s):  
Duane Storti ◽  
Mark A. Ganter ◽  
William R. Ledoux ◽  
Randal P. Ching ◽  
Yangqiu Patrick Hu ◽  
...  
Keyword(s):  
Multiscale Modeling ◽  
Computer Aided Design ◽  
Level Set Methods ◽  
Solid Modeling ◽  
Signed Distance Function ◽  
Function Representation ◽  
Signed Distance ◽  
Computer Aided ◽  
New Formulation ◽  
Aided Design

This paper describes a new formulation of solid modeling for treating parts derived from volumetric scans (computed tomography, magnetic resonance, etc.) along with parts from traditional computer-aided design operations. Recent advances in segmentation via level set methods produce voxel grids of signed distance values, and we interpolate the signed distance values using wavelets to produce an implicit or function-based representation called wavelet signed distance function representation that provides inherent support for data compression, multiscale modeling, and skeletal-based operations.

Wavelet SDF-Reps: Solid Modeling With Volumetric Scans

2007 ◽  
Author(s):  
Duane Storti ◽  
Mark A. Ganter ◽  
William R. Ledoux ◽  
Randal P. Ching ◽  
Yangqiu Patrick Hu ◽  
...  
Keyword(s):  
Level Set ◽  
Computer Aided Design ◽  
Grid Point ◽  
Level Set Methods ◽  
Solid Modeling ◽  
Closed Surface ◽  
Scanner Data ◽  
Case Scenario ◽  
Signed Distance ◽  
New Formulation

This paper describes a new formulation of solid modeling that addresses the issue of including parts whose geometry is determined from volumetric scans (CT, MRI, PET, etc.) along with parts whose geometry is designed by traditional computer-aided design (CAD) operations. Such issues arise frequently in the design of medical devices or prostheses where fit and/or interference between man-made artifacts and existing anatomy are essential considerations, but the modeling formulation presented is not limited to medical applications and can be applied to any parts whose volume can be actually or virtually scanned. Scanner data typically comprises a grid of intensity values and segmentation must be performed to determine the extent of the part. In current practice, the segmented scanner data is run through a polygonizer to obtain an approximate tessellation of the object’s surface. Even in the best case scenario where the triangles obtained form a closed surface that accurately approximates the surface of the scanned object, such triangulated models can be problematic due to excessive size. We present an alternative approach based on recent advances in segmentation with level set methods. The output of the level set computation is a grid of approximate values for the signed distance from each grid point to the nearest point on the surface of the scanned object. We propose interpolating the grid of signed distance values to obtain an implicit or function-based representation (f-rep) for the object, and we introduce appropriate wavelets to effectively perform the interpolation while also providing a number of other useful properties including data compression, inherently multi-scale modeling, and capabilities for skeletal-based modeling operations.

Computer-Aided Design Synthesis Using Syntactic Solid Modeling

1994 ◽  
Author(s):  
Vassilios E. Theodoracatos ◽  
Xiaogang Guan
Keyword(s):  
Computer Aided Design ◽  
Solid Modeling ◽  
Large Set ◽  
Complex Structures ◽  
Design Synthesis ◽  
Computer Aided ◽  
Grammar Rules ◽  
Small Set ◽  
Definition Of ◽  
Aided Design

Abstract This paper presents a new Computer-Aided Design (CAD) synthesis model which uses Plex Grammar as structural relationship descriptors and NURBS surface representation for constructing standard and non-standard solid entities. Here, the designer uses a syntactic design methodology for early topological and geometrical definition of the structure of concept alternatives resulting from the design process. This syntactic scheme provides the capability of describing a large set of complex structures by using a small set of simple entities. The recursive nature of the grammar and the hierarchical representation of the structure makes the description of complex structures simple and under the direct control of the designer. An object structure constructive tree is generated and subsequently translated into Plex Grammar production rules in order to form an Interconnection Matrix (ICM) expressing. The resulting Plex structure defined in the ICM expresses the topological information among entities which form the specific types of objects. By modifying the Plex grammar rules, various objects with different geometry and topology can easily be reconstructed. Compared to conventional solid modeling techniques, this approach provides more systematic object generation, easy manipulation and modification, control over congruity and the ability to represent sculptured shapes. Several examples of syntactic solid modeling applied in design synthesis will be presented for further usage in downstream applications.

scholarly journals Optimizing body design of a computer-assisted manual press

2019 ◽  
Vol XXII (2) ◽  
pp. 169-176
Author(s):  
Turof M.
Keyword(s):  
Computer Program ◽  
Computer Aided Design ◽  
Solid Modeling ◽  
Computer Aided Engineering ◽  
Computer Assisted ◽  
Computer Aided ◽  
Complex Program ◽  
Body Design ◽  
Aided Design ◽  
Microsoft Windows

This paper proposes a simplified design of a press body manually using a model consisting of a double symmetrical frame flush. Both Mathcad and Solidworks programs were used to determine the dimensions and drawings. MathCad is a very complex program, but also very useful for engineers, researchers, mathematicians, students, teachers, and all those who use math. Mathcad is a much better way to perform and manage engineering calculations, making them easy to achieve, understand, verify, communicate, and logically follow. SolidWorks is a solid modeling computer-aided design (CAD) and computer-aided engineering (CAE) computer program that runs on Microsoft Windows.

Laser-Chemical 3-D Micromachining

1992 ◽  
Vol 282 ◽  
Author(s):  
T. M. Bloomstein ◽  
D. J. Ehrlich
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Solid Modeling ◽  
Compression Molding ◽  
Removal Rates ◽  
Computer Aided Manufacturing ◽  
Electrodischarge Machining ◽  
Computer Aided ◽  
Manufacturing Software ◽  
Aided Design

ABSTRACTThree-dimensional parts are machined in silicon using laser-induced chlorine etching reactions. Structures are created directly from solid-modeling computer-aided-design/computer-aided-manufacturing software. Removal rates exceeding 2×104 and 105μm3/s, several orders of magnitude faster than electrodischarge machining methods, are achieved at 1-μm, and 15-μm x-y resolution, respectively. Laser-induced metallization of resulting structures as well as replication through compression molding have been demonstrated.

Computer-Aided Geometry Design of Trapezoidal Threaded Variable Pitch Conical Lead Screws

1991 ◽  
Author(s):  
Jen-Yu Liu ◽  
Hong-Sen Yan
Keyword(s):  
Computer Aided Design ◽  
Solid Modeling ◽  
Design Code ◽  
Surface Geometry ◽  
Variable Pitch ◽  
Screw Motion ◽  
Lead Screw ◽  
Geometry Design ◽  
Computer Aided ◽  
Aided Design

Abstract Based on conical screw matrix transformation, equations of variable pitch conical helix and helicoid are derived. The surface geometry of a trapezoidal threaded variable pitch conical lead screw is generated by a trapezoid with a variable pitch conical screw motion. A computer-aided design code is developed with Patran Plus solid modeling. The result of this work is necessary for the computer-aided machining of trapezoidal threaded variable pitch conical lead screws.

Incorporating Solid Modeling Into Engineering Curriculum

1991 ◽  
Author(s):  
Y. C. Pao
Keyword(s):  
Computer Aided Design ◽  
Computer Programming ◽  
Low Cost ◽  
Solid Modeling ◽  
Engineering Curriculum ◽  
Multiple View ◽  
Computer Aided ◽  
Aided Design

Abstract Solid modeling is proposed as an integral part of freshman teaching on engineering drafting, computer programming, and computer-aided design. A low-cost, commercially available software, SilverScreen, is recommended for the students to experiment on wireframe and solid modelings. In addition to providing the basic drafting needs of dimensioning, labelling text of various size and orientation, chamfering, and filleting, other topics of solid modeling are proposed for the higher-level engineering courses. It enables the students to apply multiple-view, split-screen display (such as showing the top, front, right-side, auxiliary, and section views all on one screen), and Boolean manipulation of solids (union, subtraction, and others). Moreover, students can also use SilverScreen in conjunction with other programs written in BASIC and C languages.

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