HardwareSelector 单元网格面鼠标选择

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①vtkHardwareSelector网格面的UI交互选择

二：代码及注释

import vtkmodules.vtkInteractionStyle import vtkmodules.vtkRenderingOpenGL2 from vtkmodules.vtkCommonColor import vtkNamedColors from vtkmodules.vtkFiltersSources import vtkSphereSource from vtkmodules.vtkCommonDataModel import vtkDataObject from vtkmodules.vtkInteractionStyle import vtkInteractorStyleTrackballCamera from vtkmodules.vtkRenderingCore import ( vtkActor, vtkHardwareSelector, vtkPolyDataMapper, vtkRenderWindow, vtkRenderWindowInteractor, vtkRenderer ) from vtkmodules.util.numpy_support import vtk_to_numpy ren1 = vtkRenderer() def main(): colors = vtkNamedColors() sphere = vtkSphereSource() sphere.SetCenter(0, 0, 0) sphere.SetRadius(5.0) sphere.SetThetaResolution(32) sphere.SetPhiResolution(32) mapper = vtkPolyDataMapper() mapper.SetInputConnection(sphere.GetOutputPort()) actor = vtkActor() actor.SetMapper(mapper) actor.GetProperty().SetColor(colors.GetColor3d('Bisque')) ren1.AddActor(actor) ren1.GetActiveCamera().ParallelProjectionOn() ren1.SetBackground(colors.GetColor3d('Navy')) renWin = vtkRenderWindow() renWin.AddRenderer(ren1) renWin.SetSize(400, 400) renWin.SetWindowName('Hardware Selector Example') iren = vtkRenderWindowInteractor() iren.SetRenderWindow(renWin) style = vtkInteractorStyleTrackballCamera() iren.SetInteractorStyle(style) iren.AddObserver("LeftButtonPressEvent", selectionCallback) ren1.ResetCamera() renWin.Render() iren.Initialize() iren.Start() def selectionCallback(caller, ev): click_pos = caller.GetEventPosition() # 获取鼠标在二维渲染平面的坐标 x, y = click_pos print(f"Mouse clicked at: {x}, {y}") """ vtkHardwareSelector 是一个利用 GPU（硬件渲染管线）来快速确定“屏幕上哪个对象被选中”的类 它用显卡的渲染结果来“反查”哪个几何体（actor、cell 或 point）在某个屏幕像素位置。 """ hsel = vtkHardwareSelector() hsel.SetRenderer(ren1) hsel.SetFieldAssociation(vtkDataObject.FIELD_ASSOCIATION_CELLS) # 区域内所有单元 # vtkDataObject.FIELD_ASSOCIATION_POINTS 区域内所有顶点 # vtkDataObject.FIELD_ASSOCIATION_NONE 区域内的所有对象(整几何体) hsel.SetArea(x-2, y-2, x+2, y+2) ren1.GetRenderWindow().Render() res = hsel.Select() if res is None or res.GetNumberOfNodes() < 1: print("No visible cells selected.") return sel_node = res.GetNode(0) """ 在 VTK 中，如果你想做 对象选择（Picking / Selection），通常会用： vtkSelection：表示整个选择结果，可能包含多个节点（Node） vtkSelectionNode：表示一个选择节点，包含具体的选择类型、IDs 等信息 """ sel_list = sel_node.GetSelectionList() if sel_list is None or sel_list.GetNumberOfTuples() == 0: print("Selection list empty.") return ids = vtk_to_numpy(sel_list) print("Visible cell IDs:", ids.tolist()) if __name__ == '__main__': main()