Patch doesn't respect tangency


see attached 3dm.
CP_PatchNoTangency.3dm (141.4 KB)

In V5/64 SR9 (5.9.40609.20145, 09.06.2014):
_Patch doesn’t produce a tangent surface to the inner srf edge.

In V5/32 SR8 (5.8.40225.8390, 25.02.2014), it works ok, in V4 as well .

Seems to be a bug, right?


Hi Charles - give it more spans - 30 by 30 say- that should ‘clean up the zebra’.


Worked for me. Reduce the Stiffness (Steifheit). Stiffness affects how much the new surface will distort from the starting surface. Default starting surface is a plane. I used 0.1 in the attached file.
CP_PatchNoTangency DC.3dm (74.4 KB)

Surface in example in my post above is 6x6 spans.

I like reducing the stiffness better. It looks like the problem with quite so few spans turns up when you try to join. It’s not that bad in this case but still a little too far to join.


Hmm, I already tried with other parameters, it does really not work at all.
In here, it doesn’t matter what I set, not a bit oft tangency comes out.
With idential parameters it works in SR8 and old V4.

This is the truth.

Here’s the file:
CP_PatchNoTangency_2.3dm (190.6 KB)

And what we see here:

30x30 gives this:

Or that:

I do not get anything like that- it is pretty clean here at 30 by 30 and stiffness = 1. or low stiffness and lower spans, though joining suffers with too few spans. Not perfect but better than what you show. Not sure what to say- I do have a later build than the public SR9 at the moment but I don’t think there have been any changes to Patch since sr9 was released.


Hi Charles
Te patch parameter : Select Starting Surface must be=0
Ciao Vittorio

Hi Vittorio,

wow, that’s it!

Since there was no starting surface selected and the pull value is greyed out, I didn’t see the difference in the dialog.

Now it is working as expected.

But I think it is a bug - the pull value should only kick in when a starting srf is selected.

Many thanks!

Also for me it is a bug.
Ciao Vittorio

Thanks for finding that. We’ll fix it