What CAD systems interface to TrueGrid®?


Answer: TrueGrid® uses the IGES interface so the answer is all CAD systems with an IGES output.

The IGES interface is used because the projection method in TrueGrid® only requires surfaces. Many mesh generators have a direct link to specific CAD systems. A direct link to a CAD system's data base accesses solids which would be of little use to TrueGrid® since TrueGrid® is not based on solids. This is also why we recommend that the CAD operator building the CAD geometry should not take extra steps in decomposing the geometry into simple solids. This only complicates the geometry. In contrast, a solids model (or B-Reps) is typically used by mesh generators because most mesh generators are using automatic mesh generation algorithms. These automatic mesh generation algorithms are in use because the majority of the market prefers ease of use mesh generation over quality meshes. Basically, TrueGrid® uses the IGES interface to CAD systems because it offers the highest quality meshes.

Sometimes this question is asked because someone in the past used IGES geometry to build a hexahedron mesh and it was difficult because the tool used to generate the mesh required that the surfaces meet almost perfectly. A lot of time was required to fix the geometry so that it could be meshed.

Again in contrast, TrueGrid® is unusually tolerant with imperfect IGES geometry. This is because of the projection method. In TrueGrid®,one composes many surfaces in a very easy fashion without changing the geometry. When several surfaces are composed, it does not matter if they have gaps or overlaps. When an edge of the mesh is projected to the intersection of two surfaces or composite surfaces, it is automatically done using the tangent planes. So if there is a small gap between the surfaces, the edge will be projected to the intersection of the tangential extension of the surfaces. TrueGrid® always finds the intersection. This is why IGES geometry is ideal for TrueGrid's®algorithms.

TrueGrid   Home Page

Questions, comments, suggestions
Copyright © 1996-2008 XYZ Scientific Applications, Inc. All rights reserved.

www.truegrid.com/FAQ/cad.html   April. 4, 2008