#Author: Miguel Molero <miguel.molero@gmail.com>
import numpy as np
from vtk import vtkPolyData, vtkPoints, vtkCellArray, vtkTriangle
from vtk.util.numpy_support import vtk_to_numpy, numpy_to_vtk, get_numpy_array_type, get_vtk_to_numpy_typemap, \
numpy_to_vtkIdTypeArray
from vtk.vtkCommonPython import vtkPoints, VTK_UNSIGNED_CHAR
from vtk.vtkFilteringPython import vtkCellArray, vtkPolyData
def get_polydata_from(points, tr_re):
numberPoints = len(points)
Points = vtkPoints()
ntype = get_numpy_array_type(Points.GetDataType())
points_vtk = numpy_to_vtk(np.asarray(points, order='C',dtype=ntype), deep=1)
Points.SetNumberOfPoints(numberPoints)
Points.SetData(points_vtk)
Triangles = vtkCellArray()
for item in tr_re:
Triangle = vtkTriangle()
Triangle.GetPointIds().SetId(0,item[0])
Triangle.GetPointIds().SetId(1,item[1])
Triangle.GetPointIds().SetId(2,item[2])
Triangles.InsertNextCell(Triangle)
polydata = vtkPolyData()
polydata.SetPoints(Points)
polydata.SetPolys(Triangles)
polydata.Modified()
polydata.Update()
return polydata
def get_points_normals_from(polydata):
nodes_vtk_array = polydata.GetPoints().GetData()
array = vtk_to_numpy(nodes_vtk_array)
numberArrays = polydata.GetPointData().GetNumberOfArrays()
for i in range(numberArrays):
if polydata.GetPointData().GetArrayName(i) == "Normals":
array_normals = vtk_to_numpy(polydata.GetPointData().GetScalars("Normals"))
return array, array_normals
else:
raise Exception("No available Normals")
def save_to_xyz_normals(polydata, filename):
array, normals = get_points_normals_from(polydata)
X = np.c_[array, normals]
np.savetxt(filename, X, delimiter=' ', newline='\n')
def numpy_from_polydata(polydata):
"""
Converts vtkPolyData to Numpy Array
Parameters
----------
polydata: vtkPolyData
Input Polydata
"""
nodes_vtk_array = polydata.GetPoints().GetData()
nodes_numpy_array = vtk_to_numpy(nodes_vtk_array)
if polydata.GetPointData().GetScalars():
nodes_numpy_array_colors = vtk_to_numpy(polydata.GetPointData().GetScalars("colors"))
return np.c_[nodes_numpy_array, nodes_numpy_array_colors]
else:
return nodes_numpy_array
def polydata_from_numpy(coords):
"""
Converts Numpy Array to vtkPolyData
Parameters
----------
coords: array, shape= [number of points, point features]
array containing the point cloud in which each point has three coordinares [x, y, z]
and none, one or three values corresponding to colors.
Returns:
--------
PolyData: vtkPolyData
concrete dataset represents vertices, lines, polygons, and triangle strips
"""
Npts, Ndim = np.shape(coords)
Points = vtkPoints()
ntype = get_numpy_array_type(Points.GetDataType())
coords_vtk = numpy_to_vtk(np.asarray(coords[:,0:3], order='C',dtype=ntype), deep=1)
Points.SetNumberOfPoints(Npts)
Points.SetData(coords_vtk)
Cells = vtkCellArray()
ids = np.arange(0,Npts, dtype=np.int64).reshape(-1,1)
IDS = np.concatenate([np.ones(Npts, dtype=np.int64).reshape(-1,1), ids],axis=1)
ids_vtk = numpy_to_vtkIdTypeArray(IDS, deep=True)
Cells.SetNumberOfCells(Npts)
Cells.SetCells(Npts,ids_vtk)
if Ndim == 4:
color = [128]*len(coords)
color = np.c_[color, color, color]
elif Ndim == 6:
color = coords[:,3:]
else:
color = [[128, 128, 128]]*len(coords)
color_vtk = numpy_to_vtk(
np.ascontiguousarray(color, dtype=get_vtk_to_numpy_typemap()[VTK_UNSIGNED_CHAR]),
deep=True)
color_vtk.SetName("colors")
PolyData = vtkPolyData()
PolyData.SetPoints(Points)
PolyData.SetVerts(Cells)
PolyData.GetPointData().SetScalars(color_vtk)
return PolyData
def copy_polydata_add_normals(polydata, normals):
Points = vtkPoints()
ntype = get_numpy_array_type(Points.GetDataType())
normals_vtk = numpy_to_vtk(np.asarray(normals[:,0:3], order='C',dtype=ntype), deep=1)
normals_vtk.SetName("Normals")
output = vtkPolyData()
output.ShallowCopy(polydata)
output.GetPointData().SetNormals(normals_vtk)
return output
