Convert objects made of 3D polygons to solids?

[Christiaan]

I've received a DXF file which contains 3D steelwork modelled in Strucad.

Problem is when I import it it's all made up of 3D polygon faces instead of solids. Is there any way to convert them to solid objects so I can place them in my mode and generate section drawings that cut through them?

Or maybe bring em through a different program first?

[Christiaan]

Oh, convert to mesh works!

[Tamsin Slatter]

You can also try Convert to NURBS and then use Model > 3D PowerPack > Stitch and Trim Surfaces. That creates a Generic Solid.

[Christiaan]

Thanks Tamsin. I wonder what will use less resources?

[Tamsin Slatter]

Good question... Just did a quick test and 50 x 1m cubes in mesh result in a file of 287K. The same file using the Nurbs to Generic Solids option results in 508K file. So Mesh is more efficient!

[Christiaan]

Ah ha, you're a star, thank you.

[Christiaan]

Brilliant. It's worked out quite well. What a time saver.

[Tamsin Slatter]

Of course, if I were really using 50 instances of those cubes, the best way would be to create a symbol... 50 duplicates of anything is not efficient on resources.

[Mauro Pujia]

Hi! I'm trying to solidify (if that's the correct term) a OBJ imported file full of 3D polygons. I go thru the steps that you mention, I get the final result of a Generic Solid but still with the unorganized "wireframe structure" inside, is it posible to remove? Attaching recorded video screen.

 

[VIRTUALENVIRONS]

Can you confirm the final object is a solid and not hollow inside?

[Benson Shaw]

@Mauro Pujia post the .obj. and/or the vwx file.  We can propose some actual solutions. 
 

Meanwhile, if only this object, It might be worth the effort to trace the front face with 2d shapes, clip out the openings and extrude. 
 

- B

[Kevin McAllister]

@Benson Shaw is right that the file would definitely help us propose solutions. I think I would try extracting the front face as planar surfaces, using the face mode of the Extract tool, and then using Add Surface to join everything together into one surface. From there you just extrude the surface. If you want to remove the facets around the opening you could go back in and edit the polyline (Command [). This gives you access to the cutouts which you could redraw using circles and squares combined with Add surface.

 

(Everyone should learn about editing polylines with Command [. It's very useful.)

 

Kevin

 

[VIRTUALENVIRONS]

As the shape is constant, extracting the face and perhaps just using the shell tool would be a simple solution.  But, out of curiosity I would also be interested in the original file.  I think the shape we are looking at is a hollow object.

[Kevin McAllister]

7 minutes ago, VIRTUALENVIRONS said:

 I think the shape we are looking at is a hollow object.

^ this is almost certainly true. Stitch and Trim from NURBS surfaces is usually the best option if you want to create a solid object from a collection of surfaces (NURBS or 3d polys you convert to NURBS).

 

Kevin

[Benson Shaw]

I think Extract, then Shell should be best method.  My initial thought was that the trace would produce a more viable or vertex efficient source object.  Not borne out by testing.  I think the Extract (face mode), then Shell should work really well.  I tried to approximate the obj mesh by drawing a 2d poly, clipping the openings, Extrude, then Convert to Mesh (produces a more complex mesh than the OP, but similar).  Tested the Extract/Shell process on both the extrude and the mesh.  Same result either way.  The intermediate Extrude is a good solid, but probably not worth the effort to trace, or to extract edges.

 

-B