Question/wish

[Curt Roth]

Dear T-splines team,

I have a question about shelling, I'm trying to shell my T-spline object and this goes great for about 90%.
As you can see in the screenshots I'm shelling inwards, now the shell that is created is almost good but not quite, as you can see here there are still a few naked edges.

Now my question, is it possible to create a watertight shell? if so how do I do this?
If this is not possible than this would be my strong wish for you guys to create / refine this function.

Screens:










Thanks Guys!!!!

[Adam Helps]

Try it again with today's release, please. This looks a whole lot like something I fixed last Friday .

[Curt Roth]

Hehehe, I will, thanks so much Adam!!

[Curt Roth]

Hi Adam,

It looks like it's the same as before, here are the steps I followed (of course my approach might be totally wrong ):

I started with a clean Mesh:


Converted it to T-Splines:


Used the Offset Surface command to shell inwards:




After that I used the Join command ( to join the inner shell ) :


There are still naked edges:


I hope this helps to nail this problem

[ricardo]

Hi Curt!

The usual mind blowing modelling....

May be You've been told, but have you tryied dealing with starpoint smoothness? Could help.

Cheers,

Ricardo

[TomFinnigan]

I think the crux of the problem is that the surfaces aren't G2, especially at the star points. Increasing the smoothness will give you better results, and you might be able to increase it until you hit tolerance.

We are working on making the star regions G2, but that's still in the research phase. We did have some ideas about making the star regions flat, which would be G2, but might look bad. Hmm..

Is there a mesh offset? That might give some decent results, but the wall thickness isn't guaranteed to be uniform.

[Curt Roth]

Hi Ricardo,
Thanks!! excellent suggestion that gives an almost ( fixable )watertight result!

Hi Tom, offsetting my mesh before converting indeed works even better, it only needs little tweaking before converting but gives a watertight result in an instance!

After this weekend (I'm away this weekend) I'll post the result

[Adam Helps]

Yeah, there's only so much I can do about it after you're outside of T-Splines . The T-Spline itself should never have naked edges, but once you start playing with offset surfaces, things can get a little hairy.

I agree that you are probably seeing issues with star points that aren't smooth enough. We have some ideas on better ways to improve the surface, but for now 'tsSetStarSmoothness' does a pretty good job, as long as you don't mind a heavier model.

[Curt Roth]

Cheers Adam!!

Here it is, first offsetting the mesh 2mm and than converting it to T-Splines, and back again to nurbs without using "star-point smoothness" this gives a mush cleaner result in nurbs ( less surfaces )
Btw, it's a grip

[Matt Sederberg]

Curt,

Great work! BTW, I'm curious...does this workflow (offsetting the mesh) generate an accurate enough model for your purposes?

Matt

[Curt Roth]

Hi Matt, Thanks!!

Although there is a slight variation in thickness it's perfect for what I need