Welcome to the Onshape forum! Ask questions and join in the discussions about everything Onshape.

First time visiting? Here are some places to start:

  1. Looking for a certain topic? Check out the categories filter or use Search (upper right).
  2. Need support? Ask a question to our Community Support category.
  3. Please submit support tickets for bugs but you can request improvements in the Product Feedback category.
  4. Be respectful, on topic and if you see a problem, Flag it.

If you would like to contact our Community Manager personally, feel free to send a private message or an email.

Best way to convert a mesh to a solid

john_mcclaryjohn_mcclary Member, Developers Posts: 1,494 PRO
edited January 25 in Community Support
What are the best/quickest/easiest ways to convert a mesh to a solid.

I know you can't directly convert it in Onshape.
But is there a better way other than tracing the mesh with sketches, then extrude each part?

I wish you could just boolean intersect with a giant cube.
For what I need, I just need a dumb solid, even if it has low quality / low resolution faceted faces.

Is there a free third party converter that can do this?

I tried in Solidworks but it fails because there apparently are too many entities to convert.. So much for top tier CAD

Our customer only has a solidworks assembly of the conveyor we need to interface with (and no part files [yes, we called and asked])  :'(
So the only form of the model is the 'last rebuilt parasolid' within the .sldasm
So I opened in eDrawings, then saved as STL, then tried a bunch of ways to get a usable solid into SolidWorks from the STL.

If he was working in Onshape he could just use the mesh as is and be done. (Even though I started the project in Onshape before he took it over, then he started again from scratch in SW because he is too scared to at least... try... Onshape....  but I digress)
But he insists on using Solidworks, and Onshape is the only CAD I have that can actually open it in a "usable" way. Solidworks just gives you a useless solid body with no edges/faces or vertices to build upon or measure.

So I was hoping I could do a quick import into Onshape, then export back to SW in a step, but really don't want to spend a day reverse-modeling the conveyor, when all it is need for is a reference to measure from and show in installation drawings.

Alternatively, is there a way to get the parasolid straight from the .sldasm? Instead of the STL hack I did.
Opening it in Solidworks will just give an empty assembly because all the part references are absent.

P.S. Chrome tends to crash WebGL when I open this tab sometimes. But Firefox seems to open it more stable
https://cad.onshape.com/documents/28050bca2b1ddeb0acbab720/w/72369ffa7faabbf84de28ab1/e/f2a4bbc8e201c03967c4159d

Best Answers

  • john_mcclaryjohn_mcclary Posts: 1,494 PRO
    Accepted Answer
    billy2 said:
    I'd spend 10 minutes and ask for / find another file type.

    Spaceclaim has a stl convertor tuned sketchup, but you'll waste more time converting than finding a better file. Look for IGES, STEP or Parasolids. Stay away from stl or obj.


    I would normally use a step or parasolid. But the customer only had a solidworks assembly (with no solidworks parts)
    so the only way to view the file was with edrawings. So I exported to STL because it was the only format edrawings can export.
    I hate meshes, they are not useful in my line of work. Which is why I want to convert it :)

    We called and asked, but that was all he had. (This is what happens when CAD amateurs manage project files)

    I don't see an IR for boolean intersect with mesh. Cause basically that's all I'm looking for.
    Made one here:
    https://forum.onshape.com/discussion/11000/boolean-intersect-with-mesh/p1?new=1

Answers

  • TimRiceTimRice Member, Moderator, Onshape Employees Posts: 183
    Not really a direct answer to your question...but you could create a simplified representation of the conveyor. If you only need the mounting points to be exact you could trace them from the STL and then connect the mounting points with a dummy solid that is basically just a bounding box. 
    Tim Rice | User Experience | Support 
    Onshape, Inc.
  • john_mcclaryjohn_mcclary Member, Developers Posts: 1,494 PRO
    NeilCooke said:
    @john_mcclary the SLDASM file only contains graphics (no BREP) intended for the eDrawings viewer only. How on earth did they get an assembly with no parts? If you have SW Premium, turn on the ScanTo3D add-in first before importing the mesh - that should create a mesh similar to the one you see in Onshape.
    I gave this a try, It still wouldn't let me touch entities, but it was different, I was able to see the surfacing tool, but it crashed a few times trying to convert, then I gave up because I had a skype meeting. I'll try again later, but this looks like it's heading in the right direction.

    TimRice said:
    Not really a direct answer to your question...but you could create a simplified representation of the conveyor. If you only need the mounting points to be exact you could trace them from the STL and then connect the mounting points with a dummy solid that is basically just a bounding box. 
    Yea, I like how we can do that in Onshape, I was hoping for a more one click convert to solids or surfaces. Like it would be nice if boolean would work
  • mahirmahir Member, Developers Posts: 844 ✭✭✭✭
    If you just need to interface with the model and not modify, it doesn't look too complicated once you get past all the facets/lines. It Looks like a couple mirrored I beams, a pattern of rollers, and some misc hardware/cutouts that may or may not need to be modeled for what you're doing.
  • john_mcclaryjohn_mcclary Member, Developers Posts: 1,494 PRO
    mahir said:
    If you just need to interface with the model and not modify, it doesn't look too complicated once you get past all the facets/lines. It Looks like a couple mirrored I beams, a pattern of rollers, and some misc hardware/cutouts that may or may not need to be modeled for what you're doing.
    in this case, yes. I did end up re drawing this.

    I was hoping for something less manual
  • billy2billy2 Member, OS Professional, Mentor, Developers Posts: 1,171 PRO
    edited January 30
    I'd spend 10 minutes and ask for / find another file type.

    Spaceclaim has a stl convertor tuned for sketchup, but you'll waste more time converting than finding a better file. Look for IGES, STEP or Parasolids. Stay away from stl or obj.

    john I think re-doing was your best option. That's what I would have done.


  • mahirmahir Member, Developers Posts: 844 ✭✭✭✭
    edited January 30
    I haven't done a lot of STL-to-solid, but I've done enough to know you should avoid doing it at all costs. Geomagic has some software for fitting surfaces to STL data that you can use to generate solids, but it's expensive and still very manual. Per @billy2, I bet the customer has an email hidden away where he sent someone a solid model. You can also ask him to ask his vendors if any of the parts/assembly was manufactured elsewhere. Plenty of machine/weld shops keep a copy of solid models.
  • john_mcclaryjohn_mcclary Member, Developers Posts: 1,494 PRO
    Accepted Answer
    billy2 said:
    I'd spend 10 minutes and ask for / find another file type.

    Spaceclaim has a stl convertor tuned sketchup, but you'll waste more time converting than finding a better file. Look for IGES, STEP or Parasolids. Stay away from stl or obj.


    I would normally use a step or parasolid. But the customer only had a solidworks assembly (with no solidworks parts)
    so the only way to view the file was with edrawings. So I exported to STL because it was the only format edrawings can export.
    I hate meshes, they are not useful in my line of work. Which is why I want to convert it :)

    We called and asked, but that was all he had. (This is what happens when CAD amateurs manage project files)

    I don't see an IR for boolean intersect with mesh. Cause basically that's all I'm looking for.
    Made one here:
    https://forum.onshape.com/discussion/11000/boolean-intersect-with-mesh/p1?new=1
Sign In or Register to comment.