import Rhino

# for accesssing GH classes

import clr

clr.AddReference("Grasshopper")

from Grasshopper.Kernel.Data import GH_Path

from Grasshopper import DataTree

# read geometry out of 3dm files and filter by layernames

if DoImport and FilePaths and LayerNames:

layerTree = DataTree[Rhino.Geometry.GeometryBase]() # make a DataTree

for filepath in FilePaths:

model = Rhino.FileIO.File3dm.Read(filepath)

if not model: continue

for i, layer in enumerate(LayerNames):

path = GH_Path(i)

geometry = []

objs = model.Objects.FindByLayer(layer)

for obj in objs:

geom = obj.Geometry

geom.EnsurePrivateCopy()

geometry.append(geom)

layerTree.AddRange(geometry, path)

# models can take up a considerable amount of

# memory that we don't need, so get rid of it

# after copying the geometry we want out of it

model.Dispose()