Sorry, that really didn't make much sense..

What I'd like to know is if someone can come up with a way to create a surface from the selected yellow curves. In Moi. Not cheating like I did..

Hi Lars, I think that Patch is really your best bet...

You can fill in that area in MoI by dividing things up into smaller pieces, but it will be difficult to get the kind of internal continuous result that Patch will give you.

But if you want to do it in MoI, one dividing method would be to create a polyline or curve in the center region with 4 corners like this:



Now trim the curves where that center piece touches them, which will form 4-sided regions like this:



Then you can select the curves for each 4-sided region and fill them in with the Network command:



But I think you'll get a more pleasing result using Patch.

- Michael

Hi Lars, another possibly thing you could try is to attempt to build a larger surface and then trim it, that is basically what Patch actually does as well.

So for example, I created this more regular outer boundary:



Then I drew in some guide curves using Draw curve / Freeform / Through pts:



Now you can select all these curves which form a regular grid layout:



And then run Construct / Network to build a surface through them:



Now Trim that surface using these as the cutting objects:



Select these regions to remove:



Which leaves you with this result:




The tricky thing with this method is getting enough guide curves placed so that the Network surface comes close to those trim edges.


Once again though, I still think you're better off using Patch rather than this method.

- Michael

I created a network patch from some lines then pulled points to get it to smooth curve, then I flattened the curves for the shape and bool intsect.

I merged it into the original curves and it seemd a little steeper than what was there, but I think you could turn on the points for the surface and drop all but the bottom planar ones to match what you have.

Yeah I always review after I post and the curves are not the same so.......failure again!

Hi Burr, that seems like it could be a good idea though - that would probably work although it may take a fair amount of tweaking of the surface control points to get the surface to pass close to the original curves.

- Michael

Yeah, I did a couple things but wasnt really paying attn to the original curves. (oops)

Turned out it was just a surface in that shape. Nothing close to the surface that was there. Even his surfaces didnt match the curves but they were very close.

Oh well.

Thank you for your suggestions.

Haven't tried them all yet, but did try a slightly different method with network.
Created two arcs which were very close to the original surface. The resulting network is close to the original, but looks like a patchwork when it is all done. All try the other methods to.

/Lars

Hi Lars,

> The resulting network is close to the original, but looks like
> a patchwork when it is all done. All try the other methods to.

Yes, this will be a common problem with many of the "piece by piece" approaches.

The area that you show there is all filled in, but the aesthetic result is probably not what you want - that's the reason why I would really recommend Patch as the best method since it builds one smooth surface result.

- Michael

> The area that you show there is all filled in

Ah, that's good to know, since it doesn't look that way when hiding the edges.

Hi Lars,

> Ah, that's good to know, since it doesn't look that
> way when hiding the edges.

Try selecting those surfaces and use Edit/Join to glue them together at their common edges.

If it won't glue together, then that would mean that the edges are too far apart.

Once joined you should get a better display at those areas when you hide edges because the generated meshes will have a unified structure along those edges.

When you have 2 surfaces that are just sitting next to one another but not actually joined, then the meshes that are created from them (which is what you see being shaded there) can have slightly vertex placements there, making it look like there are cracks and gaps between things. But that's just a display artifact from meshing.

- Michael

< that's the reason why I would really recommend Patch
But there is not yet Patch in MOI?

Hi Pilou,

> But there is not yet Patch in MOI?

Correct - that's why I recommend using Patch in Rhino for this situation.

- Michael

Your image here will make the same result than a "Patch" or it's an approximation?

Hi Pilou,

> Your image here will make the same result than a
> "Patch" or it's an approximation?

It's an approximation. Patch basically works in that same way, but has a fitting process that adjusts the surface to go through (or at least attempt to go through) some curves that you pick.

- Michael

Thank you BurrMan and Michael for your network-tips. I had already ruled out the idea to make a larger surface and trim it, because all I could come to think of was to make a surface of revolution and then trim that, but that wouldn't have worked for those eight cornerpoints.

The important thing for the surface is really that it's smooth and that it blends together well once you start copy it. And the networksurface seems like it does both.

Thank you very much both of you, I learned a lot.

/Lars