Fixing Geometry of Surface Models

quick and reliable transformation
of real life geometry
into models suitable for

Engineering Analysis and Computations
Rapid Prototyping
Medical Imaging Applications
Electromagnetic Computations
Computational Fluid Dynamics




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or
Send your Model to be Fixed




Background

    With rapid development of CAD/CAM and scanning technologies in recent years, the notion of using available electronic models of objects for rapid prototyping or engineering analysis such as, for example, computational fluid dynamics or electromagnetic computations, has become very attractive.

    However, CAD files developed for a particular purpose (such as manufacturing) may be completely useless for purposes other than those of the original designer.

    Typical irregularities observed in faceted CAD files, for instance, can include overlapping parts, branching facets, disconnected surfaces, missing facets, adjacent facets with sides that do not match, degenerate facets, inconsistent facet orientation, and bad aspect ratio in polygons. These deficiencies in the original models preclude their use for many applications.

    In the aircraft industry, building a high quality realistic aircraft model suitable for high accuracy electromagnetic (EM) calculations is an expensive and time-consuming task. Consequently, it is highly desirable to develop capabilities to transform existing models into models suitable for EM computations.

    In Rapid Prototyping, there is often a need to repair files generated by a CAD package so as to enable their use for a stereolithographic process.

    In Medical Imaging, ability to edit surfaces, to fill an opening or to introduce an opening, to reshape, to decimate, etc., enhances design of biomedical implants, plastic surgery planning, and design of prosthetic devices.

    CAD/CAM files and files generated by scanning technologies can be made suitable for a wide range of applicaitons with an additional, pre-processing step. This step consists of diagnostic evaluation of the model in question and subsequent modifications and/or repairs as required to produce models that satisfy the specific requirements of a particular application.
            
    We offer a quick and reliable service transforming real-life geometries, such as CAD models, into models suitable for Engineering Analysis and Computations, Rapid Prototyping, Medical Imaging Applications, Electromagnetic Computations, Computational Fluid Dynamics, etc.

    We repair surface models and produce triangulated surface meshes of high quality.




This is what engineers say

"...When we want to use a surface generated by a CAD system for computations on unstructured grids, this is what happens. CAD systems now generate surfaces as connected patches of NURBS or Bezier or other types of surfaces. Mesh generation routines must then generate the unstructured grids across these connected patches. In general, the mesh generation routines were built for applications in which connectivity across the element legs were not essential or were handled by interpolation routines within the codes themselves. For our applications, the connectivity between edges is essential... "

"...How to obtain a good aspect ratio between shortest and longest edges? Aspect ratio is the ratio of the diameter of the inscribed circle to the radius of circumscribed circle. For an isosceles (all three edges equal), this ratio is 1. The smaller these ratios are, the less memory and CPU time are needed to run computational software..."

            

"...The problem we run into is with the data set, the model. If it has missing facets, gaps, degenrate facet, coplanar facet, any of those, then your algorithms will fail. So you decide you need to do a bit of repair first. None of the available software can automatically repair the polygon "soups" 100%. Often it requires manual editing. The question is: how manual is the manual?..."

" ...Edges of adjacent facets must be matched. Nodes cannot be on the middle of edges. All nodes should have different positions..."

"...We often see a need for changing a mesh locally without having to remesh the entire geometry or making local refinements without having to reduce global element size..."

We can help!




We can help!

Get GeomFix
or
Send your Model to be Fixed




PRODUCT:   GeomFix
SERVICE:   Fixing Geometry
About Fixing Geometry        Examples of Fixed Geometry
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