Turn mesh object into polygon mesh

[Anonymous]

Hello,

I have a 3D mesh object (converted it from a solid), and I need to convert it into a 3D polygon mesh. How is that possible? I can not find any command for it. Or how do I even create a 3D polygon mesh?

Thank you!

Anna

[john.vellek]

HI @Anonymous,

I see that you are visiting as a new member to the AutoCAD forum. Welcome to the Autodesk Community!

 Here is an older thread that might help. It has a link to a third party utility that should help.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

Hello John,

Thank you for your answer. Unfortunately it does not work. I need to create closed 3D polygon mesh. I have a very complicated shape. It was a single solid object, that I have sliced up into smaller parts (a lot), then I have turned them into mesh. So if I click on one of the small 3D cubes and go to properties it shows it is a mesh. But I need it to be a 3D shaped closed polymesh, like the ones in the sample file I have attached. Using the automesher I ended up with lots of weird shaped polygons, that did not even retain the shapes of the small 3D objects I had before.

But I could not even figure out how to manually create 3D polygonmesh, like in the sample file. 

I am desperate for help.

Thank you

Anna

[john.vellek]

Hi @Anonymous,

I am sorry for my late reply and also sorry that the website I gave you didnt work.

Please describe the end result of this process.  AutoCAD can handle the 3D solids.  Why are are you going to polymeshes?  The Autodesk product that is probably best at handling meshes is 3DS Max.  Perhaps it is worth a Trial run to see if that will work in your workflow.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

Hi Jon,

Well, it is a bit hard to describe the end result. My solid was quite complex, and when I tried to turn it to polymesh with automesher some of the 3D elements even fall into faces only. I tried it on a simple box, and the end did not represent a wire frame with  a box, like 8 vertexes and 6 faces, but the lines (I guess edges) were going also diagobal within a face, and some edges of my box went missing. Unfortunately my evaluation period of automesher expired, so I can not attach it.

I need to import my object into an engineering design software, and for it to recognize the object as a 3D solid, it needs to be drawn as a polymesh.

Regards

Anna

[john.vellek]

Hi @Anonymous,

You might explore the MeshMixer tool. I was able to save a solid as a PLY format but I don't know if your other software can work with that format. In the men time I am going to see how well 3DS Max might do this for you. I know that it can create polymeshes but I am not sure how complicated it is to convert into one.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

Hi John,

Thanks for the help. Well, I do not really know what this PLY format is. Unfortunately I am not able to import ply format model into the design software I need to use. Also when I tried to import my model into meshmixer, only part of it imported... So still no luck at my end.

Regards

Anna

[john.vellek]

Hi @Anonymous,

What is the software application you are trying to bring this data into? I would like to see what other formats it can accept as the the only Polymeshes seems a  bit odd to me. This is especially frustrating as you are already starting with solids. 

I still think 3DS Max might be a strong option for this but I am not sure that it would make sense to purchase just for the sake of a conversion.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

Hi John,

The software is SAP2000, an engineering design software. Here is a summary from their help page of what the entities need to be if I want to import from dxf.

DXF entities should be coordinated with SAP2000 objects such that they import as follows: 

           DXF entity         SAP2000 object   Color

1	Point	Joint	Yellow
2	Line	Frame	Yellow
3	Point	Link (one-point)	Green
4	Line	Link (two-point)	Green
5	3D Face	Shell	Red
6	Polygon Mesh	Solid	White

Beside dxf one can import a several different formats, like igs or iges, or ifc files, and some others. I do not know these formats, or what they store, but under the same table like the one above Solid is not even mentioned. It looks like to me, that my options are pretty limited.

Thanks again!

Anna

[john.vellek]

Hi @Anonymous,

Take the original model made with solids and EXPORT to an IGES file. Then import into your SAP2000 and let me know the results.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

Hi Jon,

My original model is made up of many parts, so I simply made a 3D solid box, exported it to an iges file, which I have then imported into SAP. It does not work, the box falls into faces and line elements, it does not stay a solid box.

I really am afraid I can not go around creating  a 3D polygon mesh.

Can you try to convert a solid box into a polygon mesh in 3DS Max, and let me know if you could?

Thanks

Anna

[john.vellek]

Hi @Anonymous

Can you share the original file with me or is the same as the one you posted earlier? I will get one of my co-specialists that works in 3DS Max to give this a try. I also want to see what happens when I convert the file into IGES format and bring it into other programs to see if it imports correctly.

I have attached a 3D solid from AutoCAD and the resulting Polymesh from 3DS Max.

In AutoCAD, if you set meshtype=0, does that export better?

In AutoCAD you can create a polygon mesh by manual means using 3dmesh and Pface.

I also found this add-in in the Autodesk App Store that will let you bring in OBJ objects as polygon mesh into AutoCAD.  So, theoretically, if you have a solid you could run this add-in to get it into OBJ format and then run the first add-in to get it to convert to a polygon mesh.

Here is another thread from a while ago that shares the same frustration you are facing.

I still think IGES should work however but I don't have a way of testing it.

[Anonymous]

Hi John,

I really appreciate all your help! I tried to upload two files, but the size is too big. The one I attach here is one single solid object. This is a very complex shape though. I have divided it into small parts, but that is also not perfect, because my small shapes do not resemble a box type of object, they will have more than 8 vertexes, due to the complex surface. But that is for me to worry about later, once I figure how to do the polymesh conversion. I will try to send that file in an other mail too though.

In the meanwhile I will have a look at what you have sent.

Regadrs

Anna

[john.vellek]

Hi @Anonymous,

If I explode the solid it becomes regions. I can convert to a mesh using the MESHSMOOTH command. Have you tried his process to see if it can be imported into your other application?

I also tried an export to IGES format too to see if that could be imported.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

Hi John,

Thanks for your efforts! Unfortunately IGES really does not work. SAP does not handle solid objects from IGES format, as it is not listed in the entities list.

I had my model built initailly from 3D faces. That does import into SAP, but that is only a surface, so the object is hollow inside. And that again is not good for me.

Unfortunately it seems like this problem is not very straightforward to solve. So for now I have started investigating the use of a different software, so I do not have to turn my solid into polygon mesh.

Cheers

Anna

[Anonymous]

Hi Anna, 

I have a complex concrete dam that we need to model in CAD to get to SAP2000.  Were you able to find a solution?