How to create rectangular grid on surface?

Grasshopper
1

Hi there,

Does anyone know how to create a rectangular grid on surface in grashopper? Something along these lines , with each square 10cm and bars 5mm wide:
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but wrapping on surface.

I’ve done an experiment, but not sure how to make the squares exactly 100mm? (the U and V divisions stretch them).

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After, I’d like to be able to count all the little squares and unwrap that surface to make it flat :slight_smile:
Any help would be much appreciated!

Grid to surface test file.3dm (1.4 MB)

2

Using UV spacing is not that accurate in 3d space. For accurate grids on surfaces, something like panelingtools needs to be used: Equal Grid Across Surfaces - #10 by scottd

And also, not all shapes (in fact very few) can be covered by planar, square panels that can be unrolled to flat without stretching. To handle doubly curves surfaces some stretch or play needs to be introduced at the joints or in the panel itself. Reduce number of panel units for mapping double-curved surface - #16 by scottd

3

Hi Scott,

Thanks very much for your reply. The example from the link

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looks very much like what I’m trying to achieve, but when I try to connect my surface, I get a number of errors and don’t get a final grid (and I’m not that advanced in grasshopper to know how to resolve them!). Is there a simpler way to achieve that effect on my surface please? (or to somehow modify your code, so it would work on my surface?)

Many thanks!

4

That post was quite old. In Rhino 8 there is a replacement for Shrink Trimmed surface that needs to be replaced with a newer one.

This is the updated definition for 8. It requires that PanelingTools is installed. Grasshopper should prompt for that when the definition is opened. And Make sure to zoom out in the model. It very possibly is off screen as I believe it is building size.

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Equal Grid Across Surfaces Panelingtools V8.gh (48.5 KB)

5

Thanks David, thought for some reason it still doesn’t work on my surface thinking

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Can I be a massive pain and ask if you could test it on your computer please? (as in test your grasshopper definition on my surface in the attached file). Just to see if it’s the definition or something to do with my file? I’d really appreciate that!

Grid to surface test file.3dm (1.6 MB)

6

The problem is every shape is different, and the panel lines need to be specified for each direction.

So I might start with a panelingtools tutorial and a simple shape. Then once that happens, determining an approach to the more complicated shape can happen.

One thing that is important is to determine exactly how the shape could be split up. Is panel shape is the same, then perhaps each course should not line up. Or if the panel size changes at each level slightly that also might work. That second link sent covered many of the issues to think about.