Hi @k.honda,
to handel point cloud you have two steps
1- supervised machine learning.
2- unsupervised machine learning.
First step: supervised machine learning
1- Divide the point cloud to a group of classes (label). You can use pre train ML model. You can use Colab to run the ML model.
2- After you have clasified (labeld) pointcloud file, reload the the files inside dynamo and follow the secand step unsopervisind learing as @Ewan_Opie worte in here post.
Secand step: unsupervised machine learning
@Ewan_Opie post is give you a many way to handel point cloud unsupervised machine learning also Ewan has very important dynamo pakedge to handel point cloud Sastrugi Package.