Maintaining Accuracy With Angled Sections Along a 3D Curve

Grasshopper
1

Hi,

I have a problem that I need some help solving. I’m using sections placed along a curve, and then I use Sweep1 to create the geometry. The curve varies in the x, y, and z directions.

Here’s what the sections look like:

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The geometries turn out really well when the sections are placed perpendicular to the curve. Below you can see two geometries that meet:

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The issue arises when I have sections that need to be angled. As you can see in the image below, the geometries are formed incorrectly:

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I then use this calculation to rescale the angled sections and sweep them again. See the image below:

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Crv = section
Pt = section top point
5.5 =section width

At a quick glance, it looks okay when sweeped:

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But if you place it next to the geometry without angled sections, you can see that the angled ones have a slightly different shape. See the images below:

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Does anyone have a solution or an idea of how to achieve a more exact result? Any help would be greatly appreciated!

Best regards,
Mikael

2

No GH code with internalized geometry :question:

3. Attach minimal versions of all the relevant files

3

It’s likely that the issue you are having arises from simplistic assumption that you can simply uniformly scale the angled profile. Too see this, compare the scaled angled profile with a profile that you get when you slice the geometry you created from perpendicular profiles at an angle. You will see that this section is not a simple scaling.

1 Like
4

Hi!

Thank you for your response. I’ve attached a Rhino file and a Grasshopper file here. I hope you have time to look at them.
rotate_scale.3dm (46.0 KB)
rotate_scale.gh (9.0 KB)