Enneper Surface - how to model in Creo

[BHOoi]

Hi, I have tried approximating the simplest form of the above surface but the results are not satisfactory. I am sure this can be modeled with a better surfac equality, just that I do not know how.

  i attached here the original IGES file retrieved from internet and the step file of my own version. May be some of you could help to look at it and share with me the better way to model this surface. Many thanks in advance.

[John.Pryal]

I seem to remember modelling a surface like this some time in the distant past. I think I used a toroidal bend. I just knocked together a very basic model & it seems to create a reasonable surface. Model attached.

Regards

John

[BHOoi]

Thanks, John. Unfortunately I am still on Creo2. Possible to send Creo2 version?

[John.Pryal]

Creo 2 model attached.

Regards

John

[BHOoi]

THANKS. This is definitely another of modeling that shape and it's really a simple way.

I have also managed to improve the surface quality further as shown below:

[Patriot_1776]

I played with it, and this is the one I'm most happy with.  I think, at it's core, creo isn't really happy trying to make C2 surfaces.  There's ripples where there shouldn't be.  I wish they'd offer an upscale version (not something else) that had true C2 capability, where you could establish the boundaries, and force the resultant surface to be C2.

[BHOoi]

This is fantastic!

Would you mind to share how did you model or share your creo 2 file ? Thanks in advance.

[dschenken]

I'd rather see true analytical surfaces; the original surface is one that is parameterized. The one in the IGES file is a BSURF. I don't know if it's identical to the original surface. Unless I've missed surface-by-equation? 

[BHOoi]

The only file I got is that IGES file I attached in my first post. I don't have anything else for reference. 

[dschenken]

I meant that PTC should add analytical surfaces / surface by equation to the software. I think I understand the reason they haven't, but it would still be nice to have.

[Patriot_1776]

Here's a .stp file disguised as a .bmp file, just change the filetype back to .stp

I plan on tweaking it a touch to try and get it a little smoother.

[BHOoi]

Thanks, this quilt is very smooth! Only thing I am unable to do is to offset it, might be due to its degenerate corner. I am sure this can be improved.

[Patriot_1776]

Yeah, this is exactly what I was talking about.  I'm not liking how creo is handling this area.  Granted it's a small area, but still.  I was not able to even create the surface the way I SHOULD have been able to, I was forced to pick these edges a certain way to even get it as smooth as it is.  I have a couple more trick up my sleeve I'm going to try for fun.  Not knowing the actual math behind an enneper surface, I can only make what I THINK it is, but, regardless, I think it's a cool surface from an "artsy" perspective.

[BHOoi]

Great, do share if possible once you manage to get the best approximation.

For the sake of modeling challenge, I also noticed that its wing is symmetrical not only to left and right but top and bottom  sides too. Not sure how to describe it better but the pic below explains what I am trying to say here:

 Is this something do-able? 

[Patriot_1776]

Mine is symmetrical like that.  The "waves" are sharper, but that was because of how I did it, to be a little more dramatic.  I can round them.  I wasn't sure exactly what an enneper surface is.  I agree, we should be able to just do an equation and get a true surf.

Still no luck getting it better....

[BHOoi]

Thanks for the effort and your version is a good reference for me though. 

[BHOoi]

After many attempts, I have come to this approach which I think the best I have got so far. I include the creo2 file here for reference/comment. Hope it helps us to understand this mathematical surface better.

[Patriot_1776]

Well, I haven't given up on my first model, as it's more "adjustable" as to shape (how sharp the points are, how much the shape curles, etc.), but, as we've seen, sometimes fancier DOES cause issues.  I AM disappointed I couldn't get a better result out of the Boundary Blend in that model.

And, I have to thank you for leading me in a different, simpler, direction, which ends up being smoother still.  I used simple datum curve splines though 3 points instead of a sketch at both the ends of your boundary blend in both directions, and let the software do the work.  Same basic layout as yours, but with 5 fewer features and, it looks like, a slightly smoother blend.  This one, I'm happier with, although I would have liked the control the first try gave me.  Maybe version 7 will be absolutely the one.....  😉  I wasn't able to attach the creo3 file, but here's the .stp as a .bmp file, just delete the .bmp off the end.  Enjoy!

[Patriot_1776]

[Patriot_1776]

One thing to remember:  We are NOT getting a "mathematical surface", we are getting our APPROXIMATION of the true equation-driven surface.  I suck at math, so I really have absolutely no idea what the surface really is, I just thought it was a fun challenge and wanted to make it as smooth as I could.

[BHOoi]

Of course, we are no any way mathematical just an approximation.

Thanks for the participation in this discussion and I do find some application to this type of surface from the web. I modeled one of the examples, a chair as shown below:

I am attempting higher degree of enneper surface, enneper 3 shown below:

If you would like to get your hands dirty once more, here is the IGES file: