Am trying to "Variable Offset a surface"


I am new to Grasshopper and am using books and online videos to try to teach myself how to use Grasshopper.
I am trying to recreate a script from a book by David Bachman. For some reason the surface from points at the end keeps telling me “1. Input parameter U failed to collect data”. I have tried entering different numbers, but then it turns red, saying “1. The UCount value is not valid for this amount of points.”.
I have gone over the description and the Figure printed in the book several times, but I cannot find where I have gone wrong. It is probably something minor…
I hope that someone may be able to help me

Thanks in advance :slight_smile:

surface offset (24.4 KB)

Use the ‘addition’ component if you want to move a point with a vector.
uCount also takes one more than the number of points in the U direction

surface offset (10.0 KB)


Thank you, Antoine!
I had another look at the Figure in the book, and it was addition rather than multiplikation… :sweat_smile:

Do you have any idea, why they would not have the +1, that you added - and it made it work quite wonderfully - in the Figure in the book??

This has helped me heaps! Thank you for your fast reply :blush:

They must have i think…

Here is a source that details a bit more

Is their component with this little " * "?
If so, they wrote “x + 1”, which does the same…

Hmmm, no there is not. There is only the “Flatten” on the “P”.

But this has helped me a lot, and made it a lot clearer to me.
I will check out that link, as well. It looks really interesting

Thanks again!

how do I get control over the offset distance?

One way to do (51.0 KB)


I need control over the offset across the entire area.

I need people to ask politely and elaborate.
The offset is actually affecting the whole surface, you just want (or would like, let’s say would like) something different that only makes sense to you right now… Until you give us more details :wink:

connotations are in the mind of the beholder.

i want.

I’ll try providing more details asap.

Some kind of attractor function, perhaps? Choose attractor point with MD Slider in cyan group: (66.3 KB)

There is probably an easier way to do that… :thinking:

If I had more time, I would have written a shorter letter.
Blaise Pascal? John Locke? Benjamin Franklin? Henry David Thoreau? Cicero? Woodrow Wilson?

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I just want to be able to control the variance of the offset. I think Rhino already has some function in this regard.

I merely expect grasshopper to add parametric control is all.

You’re still using the old definition, did you try the last one I posted?

If it’s not what you’re looking for, I still don’t get the question.
Maybe a scheme and/or gh file would help us help you.

k, I wasn’t sure what you meant but after I messed with your file, I think I got excited.

But how do I make more of those all over the surface in order to control every point? edges, etc.?

And yes, I need it to be simple to implement so less skilled users can benefit from it’s power. :wink:

K this kind of works to do what I want, but not very intuitive yet.

Also, I want/need control over the variance relative to each edge per say.

:laughing: Wishing doesn’t make it so.

You can have multiple attractors, curves as attractors, formulas that produce patterns and damp the attractor effect when near an edge. All standard stuff but you have to write it:

I don’t like the attractor effect already. Maybe there’s a better way to write it…

I was hoping I’d not have to be a software programmer just to be able to interpret what I’m seeing ppl doing with grasshopper.

I’ve been trying to be a grasshopper user for years now, and it’s still not intuitive as much as it should be.

I should probably just try using regular Rhino offset tools and see how it goes, but then it wont be parametric at all…

Grasshopper is programming. Not everyone has the aptitude for it. What I posted here is only one simple example of attractors. The alternative (sometimes combined) is formulas (“expressions”) that produce patterns (“ripples”, bumps, whatever).

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