BlendSrf Doesn't Create a Tangent Blend?

Rhino Rhino for Windows
1

Hi,

I was a bit alarmed that with absolute default settings, creating a BlendSrf with Tangent / Tangent doesn’t actually create tangent surfaces?

Now, I haven’t really tracked the progression of the BlendSrf, but I do see those extra settings that occasionally are grayed out such as interior shapes and refine. It just seemed a bit bizarre that it could create something that isn’t tangent out of the box when you’ve asked for that. In this example, it would appear the interior shapes are required for tangency as opposed to optional for editing. Which just surprised me.

blendsrfdoesntmaketangentsrf.3dm (310.8 KB)

image

1 Like
2

Looks like a bug to me.

3

You need to check the “interior shapes” box in the blendsrf dialogue and all will be ok.

4

yah, that is a bit confusing, i believe that change was made in v6 already? before there was no such option if i recall that neat and correct. but i also freaked out the first time, till pascal told me all about it.

5

Hi Norbert, yeah that’s right. I just didn’t realise it would be required to just get the minimum tangent continuity blended surface out. My eyes popped out of my head a little when I saw the result.

6

To be honest, I wasn’t really aware of this myself.
It is the default setting of blendsrf (at least in my Rhino) though.

7

Either the Tangent setting should work without Interior shapes being selected (preferred).

  • or -
    The Tangent setting should only be available if Interior shapes is selected.

Looks like this thread: BlendSrf in Rhino 6 different

A post by @pascal from 2020: Blendsrf issue V6 vs V5 - #5 by pascal

Again, this is currently a bug because BlendSrf does not do what it claims to unless an apparently un-related option is selected.

3 Likes
8

you are right, i did not see that thread where pascal admitted it to be a bug. he talked me into it that its normal… hah… thanks David.

9

So it’s something that might be fixed?

It might be that I just don’t understand in enough detail the nu-nuances of blendsrf.

10

Hello- for now, just please be aware of the settings - there are many conflicting requirements (from users) pointed at this tool - one of them being to make the simplest possible surface with simple input. I think that is where this particular problem comes from - without interior shapes that contuinuity cannot be be calculated within the Sweep2 code. @rajaa , @Bill_Cook - do you have an idea if this can be fixed up?

-Pascal