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①actor的位置、方向和尺寸的控制方式，②window包含多个render，③多层render的选择交互
二：代码及注释
import vtkmodules.vtkInteractionStyle import vtkmodules.vtkRenderingOpenGL2 from vtkmodules.vtkCommonColor import vtkNamedColors from vtkmodules.vtkFiltersSources import vtkCubeSource from vtkmodules.vtkRenderingCore import vtkActor, vtkRenderer, vtkRenderWindow, vtkPolyDataMapper, vtkProperty, \ vtkRenderWindowInteractor from vtkmodules.vtkInteractionStyle import vtkInteractorStyleTrackballCamera from vtkmodules.vtkCommonTransforms import vtkTransform from vtkmodules.vtkRenderingAnnotation import vtkAxesActor def select_layer(caller, ev): iren = caller renderers = iren.GetRenderWindow().GetRenderers() if renderers.GetNumberOfItems() < 2: print('We need at least two renderers, we have only', renderers.GetNumberOfItems()) return # 初始化集合遍历 renderers.InitTraversal() ren0 = renderers.GetNextItem() ren1 = renderers.GetNextItem() """ 用于获取用户按下的键盘按键的符号名称 """ key = iren.GetKeySym() if key in ['0', 'KP_0']: # 如果是主键盘的0或者小键盘的KP_0 print('Selected layer:', key) """ 获取当前的鼠标交互样式对象 (vtkInteractorStyleTrackballCamera)，并将其默认操作的渲染器设置为 ren0 意味着，从调用这行代码开始，用户通过鼠标和键盘进行的所有相机操作（旋转、平移、缩放）都将只作用于 ren0 这个渲染器的相机 """ iren.GetRenderWindow().GetInteractor().GetInteractorStyle().SetDefaultRenderer(ren0) # iren.GetInteractorStyle().SetDefaultRenderer(ren0) # 简便写法 ren0.InteractiveOn() ren1.InteractiveOff() if key in ['1', 'KP_1']: print('Selected layer:', key) iren.GetRenderWindow().GetInteractor().GetInteractorStyle().SetDefaultRenderer(ren1) # iren.GetInteractorStyle().SetDefaultRenderer(ren1) # 简便写法 ren0.InteractiveOff() ren1.InteractiveOn() def orient_layer(caller, ev): """ 在用户完成对某一层的操作后，立即将该层相机的新视角（即方向和位置）复制给另一层， 从而保证两个层中的对象始终保持完全相同的朝向 """ iren = caller renderers = iren.GetRenderWindow().GetRenderers() if renderers.GetNumberOfItems() < 2: print('We need at least two renderers, we have only', renderers.GetNumberOfItems()) return renderers.InitTraversal() ren0 = renderers.GetNextItem() ren1 = renderers.GetNextItem() if ren1.GetInteractive(): orient1 = get_orientation(ren1) set_orientation(ren0, orient1) ren0.ResetCamera() else: orient0 = get_orientation(ren0) set_orientation(ren1, orient0) ren1.ResetCamera() def get_orientation(ren): p = dict() camera = ren.GetActiveCamera() p['position'] = camera.GetPosition() p['focal point'] = camera.GetFocalPoint() p['view up'] = camera.GetViewUp() p['distance'] = camera.GetDistance() p['clipping range'] = camera.GetClippingRange() p['orientation'] = camera.GetOrientation() return p def set_orientation(ren, p): camera = ren.GetActiveCamera() camera.SetPosition(p['position']) camera.SetFocalPoint(p['focal point']) camera.SetViewUp(p['view up']) camera.SetDistance(p['distance']) camera.SetClippingRange(p['clipping range']) def main(): colors = vtkNamedColors() cube_source = vtkCubeSource() cube_source.SetCenter(0, 0, 0, ) cube_source.SetXLength(4) cube_source.SetYLength(9) cube_source.SetZLength(1) cube_mapper = vtkPolyDataMapper() cube_mapper.SetInputConnection(cube_source.GetOutputPort()) back = vtkProperty() back.SetColor(colors.GetColor3d("Sienna")) cube_actor = vtkActor() cube_actor.SetMapper(cube_mapper) cube_actor.GetProperty().SetDiffuseColor(colors.GetColor3d("BurlyWood")) cube_actor.GetProperty().EdgeVisibilityOn() cube_actor.GetProperty().SetLineWidth(2) cube_actor.GetProperty().SetEdgeColor(colors.GetColor3d('PapayaWhip')) cube_actor.SetBackfaceProperty(back) """ vtk中，actor的位置、方向和尺寸可以通过两种方式控制 1、内部变换 actor自身提供的方法，如SetPosition, RotateX/Y/Z，SetScale等 2、外部变换 使用SetUserTransform(vtkTransform) """ transform = vtkTransform() transform.Translate(0, 0, 0) axes = vtkAxesActor() axes.SetUserTransform(transform) renderers = list() ren_win = vtkRenderWindow() ren_win.SetSize(800, 800) ren_win.SetWindowName('LayeredActors') iren = vtkRenderWindowInteractor() iren.SetRenderWindow(ren_win) style = vtkInteractorStyleTrackballCamera() iren.SetInteractorStyle(style) for i in range(0, 2): renderers.append(vtkRenderer()) ren_win.AddRenderer(renderers[i]) """ SetLayer 一个 vtkRenderWindow 可以包含多个 vtkRenderer， 每个 Renderer 都可以在不同的层（layer）上绘制。层的顺序决定谁在上面、谁在下面 层号从0开始，层号越大，越靠上。 通常，只有底层(Layer 0)的背景是可见的，对于i>0的层，如果它们没有显示地设置背景颜色，又或者 它们的演员没有完全覆盖其视口区域，那么它们将是透明的 """ renderers[i].SetLayer(i) renderers[0].SetBackground(colors.GetColor3d('DarkSlateGray')) renderers[0].AddActor(cube_actor) # renderers[0].SetLayer(0) # 重复代码 renderers[1].AddActor(axes) renderers[1].SetBackground(colors.GetColor3d('MidnightBlue')) # renderers[1].SetLayer(1) # 重复代码 for renderer in renderers: camera = renderer.GetActiveCamera() camera.Elevation(-30) camera.Azimuth(-30) renderer.ResetCamera() """ renderWindow也要设置层级数目，与render对应 """ ren_win.SetNumberOfLayers(len(renderers)) ren_win.Render() iren.AddObserver('KeyPressEvent', select_layer) iren.AddObserver('EndInteractionEvent', orient_layer) iren.Start() if __name__ == '__main__': main()
