Does anyone know if there is a way to trim a tree via C# in Grasshopper? I’m looking to achieve the same as the “trim tree” command.
Thanks!
Yes, Grasshopper is C#, so whatever it can do, you can do. Do note you’ll have a hard time duplicating components that deal with trees using a C# script component, because data is converted before it is handed off to a script component. But if you don’t mind that, then it’s just a matter of iterating over the branches of the old tree and building a new one. I’ll come up with an example.
treetrimmish.gh (35.3 KB)
private void RunScript(DataTree<object> T, int K, ref object R)
{
DataTree<object> tree = new DataTree<object>();
for (int i = 0; i < T.BranchCount; i++)
{
var path = T.Paths[i];
var list = T.Branch(i);
// Limit length of path to a maximum of K elements.
while (path.Length > K)
path = path.CullElement();
tree.AddRange(list, path);
}
R = tree;
}
3 Likes
Hi @DavidRutten, thanks for your response and example. I will give this a try!
This works perfectly, thanks again David!
Hi David and Chris,
I’m trying something similar to Chris: implementing the behaviour of Trim Tree, but in my case as part of a plugin (as opposed to a standalone C# component) with this code:
public static DataTree<object> TrimTreeD2(DataTree<object> tree)
{
DataTree<object> trimmedTree = new DataTree<object>();
foreach (GH_Path path in tree.Paths)
{
int currIndex = path.Indices[0];
GH_Path flatPath = new GH_Path(currIndex);
object currItem = tree.Branch(path)[0];
trimmedTree.Add(currItem, flatPath);
}
return trimmedTree;
}
However, when using a DataTree as argument, I get an error saying
cannot convert from ‘Grasshopper.Datatree<Rhino.Geometry.Brep>’ to ‘Grasshopper.Datatree’.
Can there be a more generic class than object?
Thanks in advance, Eduardo
Great example! But still a problem, If I try to trim all the branches of a tree, it pops up a dialog box complaining “Paths must have at least one element”, but still give me the desired result (tree is flattened), How to stop it from popping up dialog box ? Thanks in advance
See attached
DataTrees_Paths_V1.gh (117.3 KB)