How to combine all faces into single face for export as STEP, DXF, etc. File?

[lukas_dumasius]

Hi,

I'm trying to do some very basic modeling modifications to some .obj files and get them ready for import into an EM simulation software. I'm importing them as objs into Fusion, then exporting as step files, but the sim software also accepts DXF and a few other formats.

The software I'm using seems to want the body modeled as a single body to produce accurate results, so I can't have separate faces like this:

Is there an easy way to combine all of the faces into one and export as step or other format? I understand that if I needed nm/mm precision, there could be accuracy issues merging that many faces from an obj, and it depends on the quality of the obj model. For our purposes, we can tolerate a decent amount of approximation if it means somehow approximating the surface with splines, etc as best as possible without being too time intensive.

Are there any methods you'd recommend to go about this workflow? It just needs to be a decent approximation of the model. I know "decent" is vague, but I'm just looking for any kind of inspiration to get started and we can refine from there. For our ~1m-2m scale models, shifting surfaces a few mm to cm is ok for now. A more accurate approach is preferred if possible.

Attached an example of the obj I'm using. I can convert the mesh using convert mesh tool with parametric/base feature + faceted/prismatic/organic and tried using the merge face tool and a couple others, but they aren't really helping to model it as just a single face for the entire model.
There must be an easier way to approximate quickly using t splines, etc. into a single shape.

Appreciate any help!

[SaeedHamza]

You need to understand the workflow of this in fusion, there are 2 ways to do it :
1- You start by importing the mesh (obj), then you'll need to convert it to a brep body (since you want to export it as a step file), then from there, if you have multiple bodies (patches) then you can use the stitch tool to combine all of them into a single body assuming the the gaps between them if there are any are withen the stitch tool tolerence, but note that this approach won't give you a single faced body, as it depends entirly on the details of the body, which in most cases is impossible to achieve if you need all the details to be there.
Also, it's worth to note that the more faces you mesh contains, the more likely this method to fail, since Fusion doesn't handle meshes that well.
2- To recreate the whole body in Fusion using the sculpt environment, using tools like the pull tool from the modify menu, which allows you to snap your tspline geometry to the mesh, this method is better than the first one for 2 reasons, one is that you have full control over your geometry, so when modeling, the less ngons you have (any faces with edges other than 4, or a vertex with with edges other than 4, called a star vertex ) the less faces the final outcome will contain, and the other reason is that even if the mesh contains a high faces count, it won't affect the performance of Fusion, because you don't need to convert it to a brep to snap to it in the sculpt workspace.

So, using approach 2 is your best option here, and the general rule is that the less ngons you have, the less faces the final outcome contains, that means 0 ngons = a single faced body.

[TrippyLighting]

To me, the object shown in your screenshot looks like a solid body created by using the organic mesh conversion method in Fusion. You can export this as a STEP file.

I've repeated the process  to create the screenshots above. The "faces" you see are individual NURBS patches stitched together into a BRep that forms the solid body. You cannot magically merge those into a single surface.
Even if you remodel this using clean quad mesh topology, this will not convert into solid body comprised of a single NURBS surface. There will always be one, or more seams. It will still be a solid body (BRep).

What does the EM in EM simulation software stand for?

[wersy]

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@TrippyLighting  schrieb:

What does the EM in EM simulation software stand for?

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Under this name I only know Electro Magnetic Simulation.