AppendFilter使用AppendFilter合并两个不同的数据并展示

一：主要的知识点

1、说明

本文只是教程内容的一小段，因博客字数限制，故进行拆分。主教程链接：vtk教程——逐行解析官网所有Python示例-CSDN博客

2、知识点纪要

本段代码主要涉及的有①vtkUnstructuredGrid无法显示点的原因，②使用appendfilter合并不同数据

二：代码及注释

#!/usr/bin/env python # noinspection PyUnresolvedReferences import vtkmodules.vtkInteractionStyle # noinspection PyUnresolvedReferences import vtkmodules.vtkRenderingOpenGL2 from vtkmodules.vtkCommonColor import vtkNamedColors from vtkmodules.vtkCommonCore import vtkPoints from vtkmodules.vtkCommonDataModel import ( vtkPolyData, vtkUnstructuredGrid,vtkVertex ) from vtkmodules.vtkFiltersCore import vtkAppendFilter from vtkmodules.vtkFiltersSources import ( vtkPointSource, vtkSphereSource ) from vtkmodules.vtkRenderingCore import ( vtkActor, vtkDataSetMapper, vtkGlyph3DMapper, vtkRenderWindow, vtkRenderWindowInteractor, vtkRenderer ) def main(): colors = vtkNamedColors() # Create 5 points (vtkPolyData) """ vtkPointSource 快速生成一个包含随机点的 vtkPolyData 对象，以方便测试和演示 会自动在默认的坐标范围内（一个以原点为中心，半径为 0.5 的球体内部）随机生成点 """ pointSource = vtkPointSource() pointSource.SetNumberOfPoints(5) pointSource.Update() polydata = pointSource.GetOutput() print('There are', polydata.GetNumberOfPoints(), 'points in the polydata.') # Create 2 points in a vtkUnstructuredGrid points = vtkPoints() points.InsertNextPoint(0, 0, 0) points.InsertNextPoint(0, 0, 1) ug = vtkUnstructuredGrid() ug.SetPoints(points) print('There are', ug.GetNumberOfPoints(), 'points in the unstructured.') """ vtkDataSetMapper 默认会画出 几何单元 (cells)，而不是裸的点 ug里面的点，并没有创建默认的vertex单元。所以当下面的 renderer.AddActor(sphereActor) 这一行代码被注释掉，就只能看到5个点 要想看看到完整的7个点，就要给ug中的各个点创建vertex单元 for i in range(points.GetNumberOfPoints()): vertex = vtkVertex() vertex.GetPointIds().SetId(0, i) ug.InsertNextCell(vertex.GetCellType(), vertex.GetPointIds()) """ # Combine the two data sets appendFilter = vtkAppendFilter() appendFilter.AddInputData(polydata) appendFilter.AddInputData(ug) appendFilter.Update() # combined = vtkUnstructuredGrid() combined = appendFilter.GetOutput() print('There are', combined.GetNumberOfPoints(), 'points combined.') # Create a mapper and actor mapper = vtkDataSetMapper() mapper.SetInputConnection(appendFilter.GetOutputPort()) actor = vtkActor() actor.SetMapper(mapper) actor.GetProperty().SetPointSize(5) # Map the points to spheres sphereActor = point_to_glyph(appendFilter.GetOutput().GetPoints(), 0.05) sphereActor.GetProperty().SetColor(colors.GetColor3d("Gold")) # Create a renderer, render window, and interactor renderer = vtkRenderer() renderWindow = vtkRenderWindow() renderWindow.AddRenderer(renderer) renderWindowInteractor = vtkRenderWindowInteractor() renderWindowInteractor.SetRenderWindow(renderWindow) # Add the actor to the scene renderer.AddActor(actor) renderer.AddActor(sphereActor) renderer.SetBackground(colors.GetColor3d('RoyalBlue')) # Render and interact renderWindow.SetWindowName('AppendFilter') renderWindow.Render() renderWindowInteractor.Start() def point_to_glyph(points, scale): """ Convert points to glyphs. :param points: The points to glyph. :param scale: The scale, used to determine the size of the glyph representing the point, expressed as a fraction of the largest side of the bounding box surrounding the points. e.g. 0.05 :return: The actor. """ bounds = points.GetBounds() max_len = 0.0 for i in range(0, 3): max_len = max(bounds[i + 1] - bounds[i], max_len) sphere_source = vtkSphereSource() sphere_source.SetRadius(scale * max_len) pd = vtkPolyData() pd.SetPoints(points) mapper = vtkGlyph3DMapper() mapper.SetInputData(pd) mapper.SetSourceConnection(sphere_source.GetOutputPort()) mapper.ScalarVisibilityOff() mapper.ScalingOff() actor = vtkActor() actor.SetMapper(mapper) return actor if __name__ == '__main__': main()