I need to take a 3D model and export it to dxf so that I can import it into FEM analysis software, the software is very picky and the 3D elements have to be "polygon" meshes. All i can seem to create are 3D elements that export as "polyface" meshes.
I exported a model from the analysis software to try to reverse engineer the elements i needed to create Element Information shows polygon and polyface meshes as "mesh" so i cant differentiate the two before i export. All the elements the analysis software exported import back and and all my new elements were ignored.
1. What 3D elements in Microstation export directly as a dxf polygon mesh.
2. is it possible to convert objects, eg, 3D solids, to polygon mesh elements.
A polyface mesh can model any type of surface, whereas a polygon mesh can only model a UV bounded surface(mostly used for developable surface). DWG/DXF save/export generally follows this rule, but if you want a full control of mesh type, your best bet is to create grid mesh to begin with, or manually convert your surface to a grid mesh prior to saving as DWG/DXF. One way to check the mesh type is via keyin "analyze element", select a mesh, and check "Type Specific Details". If it has "Mesh style: quad grid", then you will get a polygon mesh when saved to DWG. If an FEM program only supports polygon mesh, perhaps it will convert the mesh to a surface? Otherwise a polyface mesh seems preferred as it is not limited to a developable surface and is free from a separate boundary definition. If the program attempts to build solids from surfaces, perhaps it also actually imports a solid file format such as Parasolid, ACIS, IGES, etc? If it is a BEM(Boundary Element Method), then a polyface mesh seems like a better choice. Might be worth of checking this with the vendor.