import rhinoscriptsyntax as rs
cloud = rs.GetObject(“Select point cloud”)
if cloud:
point = rs.GetPoint("Point to test")
if point:
cloud = rs.PointCloudPoints(cloud)
index = rs.PointArrayClosestPoint(cloud, point)
if index is not None:
point_id = rs.AddPoint(cloud[index])
rs.SelectObject( point_id )