# Tutorial Set 3

Grasshopper logic and tutorials

_GH Definition Examples:

All definitions now updated for consistency with version 0.8.x

Tutorial-Specific Definitions

Grasshopper Techniques 1: Surface Panelization/Panel Component Design and Control / 39:33 min

Grasshopper Techniques 2: Controlling Component Geometry with External Data / 12:55 min

Grasshopper Techniques 3: Mapping Curves to Surfaces / 7:34 min

1. Thanks a lot.

2. These are excellent and greatly appreciated.

I’ve got version .60055 of Grasshopper and the method described in part 1 above doesn’t work any more since the divide component doesn’t work the way it used to. The .ghx files in the download do work, but rebuilding it in the newer version doesn’t work.

It took me a long time to figure out what was going on. I downloaded the Surface Diagrid file, which superficially looked exactly the same as mine, but clicking on the two divide components revealed that the downloaded one is now marked as obsolete. The results are not the same.

If anyone can post an explanation of what’s going on now and how the same thing could be done in the newer version, it would be very helpful to me and to the others that are sure to find this site now that the Grasshopper blog links to it.

3. Hi –

The problem has to do with the way the divide surface component outputs data trees in the new versions of GH. If you compare the tree structure of the obsolete component and the new one with the “param viewer,” you will see that where the old one simply split up lists by input surface, the new one also separates them by U and V divisions. Essentially, you are getting U lists of V points. If we only had one input surface to divide, we could simply flatten the output, but since we have to preserve the data structure of the input surfaces – one list per subsurface – we need to use the path mapper component to “flatten one level” of the data tree. Pull down a path mapper, and set the source to be {0;0;A;B}, and the target to be {0;0;A} — this will revert the resulting data structure to match the way the old surface divide component worked. I hope this explanation is helpful; look out in the next couple of days for updated versions of these definitions that work with the latest versions of Grasshopper.

4. i’m truly thankful for these sets of tutorials. very nice work, and thanks for the detailed explanation behind each doing.

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6. Thank you! Great job!!!!