Hi everybody, I have a scanned plan of a curve on a rectangular grid and want to de-warp it. Since I have the measure of the original grid there are some possibilities. The best I came up with is box-morph: Creating a srf from each grid (isoCrvs aligning) and then morphing it from the distorted srf to the undistorted one. [2026-08-10 15_30_10-Grasshopper - unnamed] [grafik] What do you think of it? Maybe someone has a better idea? The example file: 260810_De-warp_grid.gh (30.6 KB) Thanks for your input. Best, Baris edit: Thanks for putting it in the correct category @martinsiegrist. You are a flash!

This would also work with mesh cage morph 2 which accepts not only points but also curves. [image] 260810_De-warp_grid_mcm2.gh (35.2 KB)

[image] Martin Siegrist: mesh cage morph Thanks. The curve looks a bit cleaner and may be the best so far. The result is quite similar to the surface box morph. In comparison, Map to Srf is a bit different, what makes sense, since it uses another logic (I guess the uv points).

Why aren’t you just using Sporph? The result looks ok

You are right. I tried several things yesterday, and finally I came up with two surfaces. Now all the morphing tools seem to work, while the box morph seems to be the most complicated one. Still it would be interesting to know which output could be considered as the best, or from which method one could expect the most exact result.

Have you tried with Shape Mapper?

I don’t know. Is it only for bitmap images?

I have no idea, I’m trying to stay away from decorative patterns and yet need to be convinced to use Shape Mapper.

[image] Martin Siegrist: I’m trying to stay away from decorative patterns and yet need to be convinced to use Shape Mapper. Reminded me of: [image]

I made a test based on the ideas from the thread yesterday. I draw a curve on a grid and took a screenshot from a perspective as input. My findings were, that the methods were quite similar (as expected): [grafik] Methode maxD RMS Totaldev BoxMorph 1,35 0,41 61,74 MapCrv 1,35 0,42 66,26 Sporph 1,35 0,40 59,85 MeshCageMorph2 1,32 0,42 67,45 MeshMap 1,34 0,42 66,35 Edit: I updated the table and the picture with @René_Corella’s proposal.

De-warp a curve on a grid (scanned architectural plan)

Grasshopper

martinsiegrist (Martin Siegrist) August 11, 2026, 2:47pm 17

Here’s an example from a while ago:

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De-warp a curve on a grid (scanned architectural plan)

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