Fixing Mesh before convert in to surfase

Hello! I’m Igor My goal to fix obj mesh file before to convert in to surface. Main problems i have , to fix edges on my model File is to big to post 3750KB. is there any particulat tutorial I can find how to get it done? Thank you! Igor.

If you want to repair a mesh check out the mesh repair tools in the Mesh drop down menu, there are tools for filling holes, unifying normals, reducing the mesh etc. If you plan on making a NURBS surface from a Mesh, this is called reverse engineering and it’s complicated… here’s a wiki article about using Rhino in this area.

4MB isn’t too large to upload but it you meant 40MB you could use if you wanted me to take a look. Just let me know if I’m confused about what you’re hoping to do.

Thank you Very much for reply! I do not cee even tool for attaching or upload emage on this forum. Try if I can do it ? So if you can open it ; You can see the edges is to bad . along the all model. This is the shell from model of airplane fuselage. My biggest problem; I do not have experience , how to fix edges along the contour ? I would think it need cad fixing in Rhino I have saved in OBJ. STP. igs. and Even converted in SW part as surface.

<img src=“” width=“690”

I still don’t know if this is a mesh or a NURBS surface and if you need a mesh or a NURBS surface after the edges are fixed. I think it’s a mesh but I’ve seen auto-surfacing software that makes an isocurve structure like what you’re showing too. There are a few manual processes that come to mind if you wanted to trim off an area or draw curves using vertex snaps and then reverse engineer the form by hand. All of these workflows will be tough for a beginner and would take practice though.

Thank you! How can I check if it is mesh or NURBS ? So I vent trough all mesh process to simplify end so on. I think It is still mesh. I was able to convert it to SW part as surface. Is there tutorials how to fix edges , or do you know who can help me to fix edges ? I need to make nice clean model of scanned object. Understand it is hard for beginner like me, but may be you point for source for help like this? Thank you! Igor.

Does that object get selected if you use the SelMesh command? Or you could use the What command on the object to find out what it is.

No! If I open file , and in command bar started to type S ,than long option box came out , with list of commands I’ve clicked SelMesh and object is not highlighted. If this what you asked for? I can highlight it by describing box over subject , with cursor. What else I can do to verify what condition of file is? Using file properties or so ? I try to attach my file below , if it can go trough e mail , 11.9 MB.
Surf mesh IGES.igs (11.2 MB)

This is in addition for Igor’s Panchenko previous letter ; This file I can open in SW as surface but can’t do any thing with it in order to fix geometry , make splines and re loft it.

This is STP file of same object
Surf Mesh.stp (10.6 MB)

STP or other non-native formats imported into SolidWorks are essentially “dumb” surfaces because you don’t get any of the parametric history, even if it was created that way in the exporting application.

In SolidWorks, you need to create intersection planes to extract splines, for lofting or boundary surfaces. After creating all new surfaces, then you will then have a parametric history which can be modified.

I’ve now been able to take a look at that file.
There are 708 surfaces in it - no meshes. All surfaces are made of pretty heavy patches.
It’s not only the edges that are a mess in this model - the picture below shows the edges of one of the patches.

As Brian wrote in his first post above, reverse engineering is complicated - it’s one of the hardest things to do in 3D modeling. Read the wiki article that he linked to in that post - especially the ‘Scan, Cleanup, Remodel’ PDF that is linked.

In short, your process will be: rotate the model so that it is aligned with the x-y-z axes. Use Section to get curves. Clean up those curves making sure that you have just enough points to describe the shape (and use the same amount of points in all sections). Loft the curves. For the cockpit area, make curves that extend to the vertical plane through the axis of the aircraft - as if there was no cockpit. Cut the cockpit out at the end.

Thank you very much for your tips ! Will try to do what you have recomended. Igor.

I would also make the tail surface as a separate object. So first make the fuselage and then trim this with cockpit and tail surfaces.