Grasshopper

generative modeling for Rhino

# Choppy lofted curve

Hello everyone!

As my first post here on GH forums I'm looking for some help to solve a problem I have with choppy lofted curves. I'm lofting between a waveform curve and it's offset in the Z-plane but the loft becomes all choppy and ugly. The loft I'm searching for is smooth and nice.

Below is my definition, image of my canvas and an image of the unwanted result.

Hope someone could share their knowledge on how to battle these evil lofts!

EDIT: When I took some printscreens the loft in Rhino seens quite good but why are they still choppy in GH?

//Oliver

Tags: choppy, curve, loft

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GH just displays curves oddly sometimes, It usually always translates back to rhino correctly.
Chris

Chris: It gives me almost the right geometry but it's still a bit choppy when you zoom in.

But the following question is; What geometry will GH follow in the later steps, the choppy or the correct in Rhino? Because this is not the final geometry...

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Another question is how can I place these curve on a surface? Tried with "Curves on surface" but couldn't figure out how to create uv-points for this geometry. Anyone got a clue?

Thank you!

Oliver

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In any case here you're only looking at the display mesh and not the geometry.  The geometry will be correct.  It's just an issue for presentation purposes.  I'm not sure how to adjust the settings in the mesh component for greater refinement. They may already be max-ed out.

Chris

the "red" grasshopper ghost is choppy alot, it always bakes into rhino correctly, its just a display issue with grasshopper, for the curves try map to surface or project to surface.

Oliver,

I took a quick stab at "remapping" your pattern from one surface to the next.  the attached sketch is pretty rough, but the logic is as follows;

-Create grid of uv points on a surface, (base surface)

-Cull the columns/rows to get alternating points

-weave points together and generate horizontal interpolated curves

-mirror those curves, (planes at first point in each row)....clean up first and last curves

-divide curves by number of U divisions and find closest points on base surface

-Reference in target surface from Rhino

-Evaluate the referenced target surface with the UV coordinates of the Base Surface.

(with both surfaces reparameterized, the UV domains will both be 0 to 1, therefore, evaluating the target surface with the UV coordinates of the points on the base surface, the points will be effectively "remapped" to the target surface).

anyway, I hope that helps you understand one way to "remap" uv coordinates from one surface to another.

GH 8.0051

Rhino V5 WIP 9/7/2011

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Hello Chirs and thank you for taking time solving the problem.

I have a final question about the symbol used in the picture of you GH canvas. I use GH v. 8.0010 and don't have the same functionality as you. What are the symbols at the end of Mirror and Basepattern.

Thank you once again!

//Oliver

the symbol represents that the data tree has been "simplified".  Simplify is available by right clicking on a component input/output, (similar to graft, flatten, etc..)  It was introduced in one of the recent releases.  The same functionality could be achieved by using the path mapper component.

EDIT: I should clarify, the simplify tree component, (sets->Tree->simplify Tree has been around for the last few releases). The ability to right click on a component input/output and choose simplify is reasonably new).

In this case, it was used to "clean up" the data structure.  I think the definition will still work with out it, but the data trees start to get a little messy.

David describes it much better here.

http://www.grasshopper3d.com/forum/topics/problem-with-the-simplify

Thank you very much Chris! Your help has guided us in the right direction and we're been able to proceed with the project.

//Oliver

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