# Flow along surface: pattern distortion

Hey anyone who knows how to create straight lines in the patterns, or why this gets bend on the target surface?

Thanks! Hannes

Hi Hannes,

The base circle of the cone is longer than the top circle.
So in order to map the rectangular shaped lattice over the cone it needs to be distorted, this distortion creates the bends in the lattice.
In the image below and this file (Unrolled_Cone.3dm (366.1 KB) ) I tried to reverse engineer straight lines on a cone onto a rectangular surface.

You will have to deal with distortion when mapping from one surface to another if they are not of equal type geometry. Itâ€™s up to you to decide how the distortion is regulated.

HTH
-Willem

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THanks a lot @Willem this makes everything pretty clear! Will get into this!

@Willem for this purpose is there a function in Rhino to simply straighten curves to straight lines by itâ€™s original length? Thanks a lot for helping me!

Hey Mitch and do you know how to match all points precisely, since there are no definitions like in solid works

Found a solution with drawing a guide line (both lines) and go for intersection snapping

Canâ€™t do it precisely via curve length with this one. So this might be average onlyâ€¦

No there is not unfortunately.
However with these values, a precision of 0.00 should suffice in my opinion.

-Willem

This looks like a nice job for Grasshopperâ€¦ --Mitch

Except there is no solution:

-Willem

I think you will need to work with imaginary numbers for that one thenâ€¦
â€“Mitch

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So anyway I did it nearly the same approach with the bottom surface, get a very decent result, but itâ€™s strangely shifted. Any ideas?
@Helvetosaur Mitch got my hands on the Lynda training series for Grasshopper today, do you have any idea how the learning curve is? (no scripting experiences, designer only

It looks like the base surface is a trimmed plane- flowing works from the full underlying surfaceâ€™s UV. Try making a base surface by lofting two opposite edges of the one you have now.

-Pascal

Absolutely right! As you see in the image below. Thanks for your hands on this @pascal