topic Re: Polygonal modelling, again. Killing Me Softly edition. in Fusion Design, Validate & Document Forum

Polygonal modelling, again. Killing Me Softly edition.

Anonymous — Thu, 09 Apr 2015 03:03:09 GMT

Since polygonal objects are virtually impossible in fusion, I modelled this quickly in Max as a surface, and imported.

But I can’t seem to find any way of using it. T-Spline faces doesn’t work because the mesh has triangle faces, and all conversions fail. Tried Patches but they don’t interact in any way with the model.

Is there any other method I could use this mesh? Maybe some other filetype I can export/import? (I used fbx)

If I need this in Fusion, what would be the best way to model it?

Thanks.

Re: Polygonal modelling, again. Killing Me Softly edition.

jeff_strater — Thu, 09 Apr 2015 03:31:05 GMT

Today, all you can really do with a mesh model in Fusion is look at it, and use it in TSplines to do "object snapping". It's pretty limited - Fusion is not yet a mesh modeler.

However, I think you can do this kind of polygonal modeling in Fusion pretty easily. THis is a simpler case, of course, but I was able to this in just a few minutes using sketching, Move, Patch, and Stitch:

Here is a screencast of how I did it: http://autode.sk/1NVh3cN

Hope this helps,

Jeff Strater (Fusion development)

Re: Polygonal modelling, again. Killing Me Softly edition.

Anonymous — Thu, 09 Apr 2015 04:08:03 GMT

I used that method for a few lopoly models, but 150 points to position by hand is a bit much.

The tspline face drawing with mesh snapping is great but it hates triangles.

Any other software/conversion/format I could pass this through to get it a bit closer to what I need, or simplify the work?

From what type of files can Fusion import actual solids and surfaces?

Thanks!

Re: Polygonal modelling, again. Killing Me Softly edition.

jeff_strater — Thu, 09 Apr 2015 04:30:47 GMT

Fusion can read a lot of BRep formats: STEP, IGES, and some proprietary formats like Solidworks, parasolids, etc. I don't know of any reliable general conversions from mesh to BRep, but if you find one, great. It's a bit of a complex topic, to be honest.

There is one option inside Fusion: In Direct Modeling (not in a history document), you can convert a mesh directly to BRep.

However, this should be used with great caution: It creates one BRep face for each triangle in the mesh. So, very simple models, it works OK, but once you get above a couple thousand triangles, you will likely not be happy with the results - the performance will not make you happy. But, this might work for models like in your post.

Jeff

Re: Polygonal modelling, again. Killing Me Softly edition.

schneik-adsk — Thu, 09 Apr 2015 05:09:25 GMT

You can create a base feature, import the mesh and then convert to brep. this allows the same workflow above but in a timeline document.

Re: Polygonal modelling, again. Killing Me Softly edition.

Anonymous — Thu, 09 Apr 2015 12:06:55 GMT

Haven't used direct modelling much, but I clicked Do Not Capture Design History, but the mesh to brep fails. Is it because my mesh is a surface not a solid?

Re: Polygonal modelling, again. Killing Me Softly edition.

Anonymous — Thu, 09 Apr 2015 12:10:00 GMT

You can create a base feature, import the mesh and then convert to brep.

Not sure I'm familiar with base features. But I think my mesh would still fail...

Re: Polygonal modelling, again. Killing Me Softly edition.

deyop — Thu, 09 Apr 2015 13:07:58 GMT

Similar to creating a Form Feature a Base Feature can be created to utilize other modeling functions including Patch capabilities. You can access it through the Create dropdown. If you can attach your mesh we can try to determine the problem with the conversion.

Is there a specific form you are trying to accomplish with this technique?

Thanks

Re: Polygonal modelling, again. Killing Me Softly edition.

Anonymous — Thu, 09 Apr 2015 13:18:56 GMT

Indeed, tried STL and IGES and both resulted in meshes, not anything usable.

To your knowledge, is this doable in any other software? Inventor, solidworks, etc?

Re: Polygonal modelling, again. Killing Me Softly edition.

jeff_strater — Thu, 09 Apr 2015 14:47:04 GMT

It should be fine to convert a surface mesh to BRep (that bunny in my screenshot is a surface). If you send me the mesh file (jeff.strater@autodesk.com), I can take a look at it, see if there is anything obvious that is causing the conversion to fail. This mesh looks small enough that performance should be fine, as well.

Jeff

Re: Polygonal modelling, again. Killing Me Softly edition.

Anonymous — Thu, 09 Apr 2015 18:27:45 GMT

Reporting back. After trying out a dozen formats that max can output, through the magic of OBJ files I have a tspline editable body! After the conversion it was all smooth, but with creased edges it's exactly my model.

Thanks for the support.