ColoredElevationMap 根据标量进行颜色映射

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①标量的颜色映射

二：代码及注释

import vtkmodules.vtkInteractionStyle import vtkmodules.vtkRenderingOpenGL2 from vtkmodules.vtkCommonColor import vtkNamedColors from vtkmodules.vtkCommonCore import vtkLookupTable, vtkMinimalStandardRandomSequence, vtkPoints,vtkUnsignedCharArray from vtkmodules.vtkCommonDataModel import vtkPolyData from vtkmodules.vtkFiltersCore import vtkDelaunay2D from vtkmodules.vtkRenderingCore import ( vtkActor, vtkPolyDataMapper, vtkRenderWindow, vtkRenderWindowInteractor, vtkRenderer ) def main(): named_colors = vtkNamedColors() points = vtkPoints() xx, yy, zz = 0.0, 0.0, 0.0 GridSize = 20 rng = vtkMinimalStandardRandomSequence() rng.SetSeed(8775586) for x in range(0, GridSize): for y in range(0, GridSize): rng.Next() xx = x + rng.GetRangeValue(-0.2, 0.2) rng.Next() yy = y + rng.GetRangeValue(-0.2, 0.2) rng.Next() zz = rng.GetRangeValue(-0.5, 0.5) points.InsertNextPoint(xx, yy, zz) inputPolyData = vtkPolyData() inputPolyData.SetPoints(points) # Delaunay2D delaunay = vtkDelaunay2D() delaunay.SetInputData(inputPolyData) delaunay.Update() outputPolyData = delaunay.GetOutput() # 获取其包围盒 bounds = [0.0] * 6 outputPolyData.GetBounds(bounds) # 得到z值的范围 minz = bounds[4] maxz = bounds[5] # 构建颜色映射表 colorLookupTable = vtkLookupTable() colorLookupTable.SetTableRange(minz, maxz) colorLookupTable.Build() # 遍历点并应用颜色 colors = vtkUnsignedCharArray() colors.SetNumberOfComponents(3) colors.SetName("Colors") for i in range(0, outputPolyData.GetNumberOfPoints()): p = [0.0] * 3 outputPolyData.GetPoint(i, p) dcolor = [0.0] * 3 colorLookupTable.GetColor(p[2], dcolor) # 利用当前点的z值得到其对应的rgb颜色 color = [0] * 3 for j in range(0, 3): color[j] = int(255 * dcolor[j]) colors.InsertNextTuple3(color[0], color[1], color[2]) outputPolyData.GetPointData().SetScalars(colors) # Create a mapper and actor mapper = vtkPolyDataMapper() mapper.SetInputData(outputPolyData) """ 由于已经用 outputPolyData.GetPointData().SetScalars(colors) 将颜色数组设置在了默认的 Scalars 槽位，Mapper 应该能够自动找到并使用它 """ actor = vtkActor() actor.SetMapper(mapper) # Create a renderer, render window, and interactor renderer = vtkRenderer() renderWindow = vtkRenderWindow() renderWindow.AddRenderer(renderer) renderWindow.SetWindowName('ColoredElevationMap') renderWindowInteractor = vtkRenderWindowInteractor() renderWindowInteractor.SetRenderWindow(renderWindow) # Add the actor to the scene renderer.AddActor(actor) renderer.SetBackground(named_colors.GetColor3d("DarkSlateGray")) # Render and interact renderWindow.Render() renderWindowInteractor.Start() if __name__ == '__main__': main()