Create Solid from Topo surface for 3D printing

[AndycMacp]

We just got a new 3D printer in the office and we are trying to find a way to print a topo surface. I've read blogs and watched tutorials but have struggled with each one. Does anyone know of a good tutorial or a plug in to export a topo surface as a mass in a STL file? If seems a little weird that Revit doesn't have this inbuilt!

Thanks in afvance, Andrew

[ToanDN]

Export the topo to DWG, open it in AutoCAD and delete all of the surfaces then you will end up with 3d polylines. Use loft command to form a solid from them in AutoCAD.

[Viveka_CD]

Hi @AndycMacp

Here is the screencast of a simple test.

I used a section box, where the sides and bottom of the top surface are cut, and this exports to an STL format

Revit model and the STL attached for reference.

Regards,

[AndycMacp]

Hi Viveka

Close but not quite. The STL the Section Box produces only contains side 'elevations' not the actual topo surface. Please see screenshot below.

ToanDN

Extracting to DWG is OK but this produces 3D Faces, which when exploded create lines - that in turn can not be lofted. Would you mind explaining in a little more detail what the AutoCAD steps are, I'm not that proficient outside Revit.

Thanks

Andrew!

[chrisplyler]

I've never done any 3D printing.

But I was able to export the topo - isolated and in a section box - to an STL file. I then used that STL file as a mesh in Fusion360.

I converted the mesh into a Brep body. This creates a 2D surface I can use. I extruded a cube that enclosed that surface, and then used the surface to split the cube. Then I just removed the top half of the cube that had been split, and I got what you see in the screencast below. Fusion360 has the ability to output to a 3D printer utility.

[Viveka_CD]

Hi @AndycMacp

I see what you are saying. 

I'm wondering if a combination of the section crop method and @ToanDN's method of contour line loft might do the trick. 

Regards,

[AndycMacp]

Hi Chris, can you record exporting the topo clipped by a section box to a STL as when we try it does not export the surface...

[Viveka_CD]

Thanks for sharing this interesting workflow @chrisplyler

Here is a discussion which has more information on the process from exporting to a SAT file format (from AutoCAD) to Fusion to a 3D printer.

@AndycMacp If you have questions with regard to this import in AutoCAD, @john.vellek is the best point of contact.

Regards,

[ToanDN]

Revit to CAD solid.

https://knowledge.autodesk.com/community/screencast/4766c55e-d58c-4a50-b701-d10a503e88b2

[Viveka_CD]

@ToanDN Does the 3D solid you've created export to STL as a water tight mesh?

[chrisplyler]

Sorry. I misspoke. I exported a DWG from Revit. Then did this in Fusion360:

[ToanDN]

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@Viveka_CD wrote:

@ToanDN Does the 3D solid you've created export to STL as a water tight mesh?

---

Here are the files.

[AndycMacp]

Thank you all for your excellent replies. It's probably my shortcomings but I hope this assists other people with the same issue.

Methods tried: 

The section box to STL really doesn't produce the topo (screenshot 1)

Exporting the topo as DWG profiles and lofting doesn't work for me either, may the site is too complex? (screenshot 2)

I've not yet tried the Fusion 360 method, I don't have that programme and never tried it.

Files attached, RVT and DWG 🙂

[Viveka_CD]

Hi @AndycMacp

This is turning out to be an interesting thread with so many workarounds.

Can you post your contours minus the buildings if possible? I' sure the experts will be ready to test it with their respective workarounds.

We are almost there!

Can you try this for me?

1) After you do the section crop in Revit, export it as a dwg in AutoCAD

2) Then use CONVTOSURFACE and select the open surfaces to make the mesh watertight

3)  Export to STL and print preview if you've got the full model for 3D print

Also see: To Create a Drape Mass Element (A drape is useful when you are working with a conceptual model of a building site. )

Looking forward to hearing from you.

Regards,

[AndycMacp]

Hi Viveka, it is and we are so grateful for everyone's help!

I uploaded the topo only in the post above, called Landscape only as RVT and DWG. I'll try the AutoCAD workaround later today. 

Ultimately, having the ability within Revit to export the topo as a mass for 3D printing would be excellent. Our practice has just got into 3D printing so I'm sure this must be a function that would benefit many others.

Thanks, Andrew

[temel1955]

Hi,

Have you ever tried to use “STL EXPORTER” plug-in for Revit?

[Viveka_CD]

Hi @AndycMacp

You are very welcome! I'm happy to see a lot of participation in this thread.

Let me know how the AutoCAD workaround turns out. I see if I can test your landscape later this afternoon.

Yes, this would be beneficial to the advent of 3D printing.

Hi @temel1955

thanks for sharing. The STL exporter works for solids, the OP's toposurface needs to become a solid mass before a successful export to the 3D printer.

Regards,

[Anonymous]

I’m unsure where I read this to sight properly, but I found exporting to FBX, then importing to https://clara.io and doing some minor tidying, then exporting to STL worked. I imagine 3d Max would work too instead of https://clara.io, I just don’t have it installed right now.

[Anonymous]

Hello

I am now dealing with the same problem, I am actually astonished that revit has such a flaw.

Well, I would like to know if you were able to find a way to export the topo surface to stl as solid.

Thanks in advance!

[AndycMacp · Accepted solution]

So I eventually got it to work via a Dynamo script. I have no experience with this add-in but this forum post provided all I needed. I think it worked properly on the 4th or 5th attempt: https://forum.dynamobim.com/t/create-a-solid-from-a-topography/6001/17

I entirely agree, it seems mad in this day and age Revit can't export topography straight to a STL, given this must be quite a common workflow, in Architecture at least!

[Viveka_CD]

That's so cool @AndycMacp 

Thanks for getting back to us on this thread and sharing your images!

This will benefit the community seeking similar solutions.

Regards,