python - 如何在不同颜色的vtk中显示点云？

Question

我有一个点云，我想在 vtk 中可视化。我想根据某些条件以不同的颜色查看它们。我正在使用 python。

关于如何做到这一点有什么建议吗？

非常感谢

Answer 1

下面是一个基于 z 轴值设置点颜色的示例。

import vtk
from numpy import random

class VtkPointCloud:

    def __init__(self, zMin=-10.0, zMax=10.0, maxNumPoints=1e6):
        self.maxNumPoints = maxNumPoints
        self.vtkPolyData = vtk.vtkPolyData()
        self.clearPoints()
        mapper = vtk.vtkPolyDataMapper()
        mapper.SetInputData(self.vtkPolyData)
        mapper.SetColorModeToDefault()
        mapper.SetScalarRange(zMin, zMax)
        mapper.SetScalarVisibility(1)
        self.vtkActor = vtk.vtkActor()
        self.vtkActor.SetMapper(mapper)

    def addPoint(self, point):
        if self.vtkPoints.GetNumberOfPoints() < self.maxNumPoints:
            pointId = self.vtkPoints.InsertNextPoint(point[:])
            self.vtkDepth.InsertNextValue(point[2])
            self.vtkCells.InsertNextCell(1)
            self.vtkCells.InsertCellPoint(pointId)
        else:
            r = random.randint(0, self.maxNumPoints)
            self.vtkPoints.SetPoint(r, point[:])
        self.vtkCells.Modified()
        self.vtkPoints.Modified()
        self.vtkDepth.Modified()

    def clearPoints(self):
        self.vtkPoints = vtk.vtkPoints()
        self.vtkCells = vtk.vtkCellArray()
        self.vtkDepth = vtk.vtkDoubleArray()
        self.vtkDepth.SetName('DepthArray')
        self.vtkPolyData.SetPoints(self.vtkPoints)
        self.vtkPolyData.SetVerts(self.vtkCells)
        self.vtkPolyData.GetPointData().SetScalars(self.vtkDepth)
        self.vtkPolyData.GetPointData().SetActiveScalars('DepthArray')

pointCloud = VtkPointCloud()
for k in xrange(1000):
    point = 20*(random.rand(3)-0.5)
    pointCloud.addPoint(point)
pointCloud.addPoint([0,0,0])
pointCloud.addPoint([0,0,0])
pointCloud.addPoint([0,0,0])
pointCloud.addPoint([0,0,0])

# Renderer
renderer = vtk.vtkRenderer()
renderer.AddActor(pointCloud.vtkActor)
renderer.SetBackground(.2, .3, .4)
renderer.ResetCamera()

# Render Window
renderWindow = vtk.vtkRenderWindow()
renderWindow.AddRenderer(renderer)

# Interactor
renderWindowInteractor = vtk.vtkRenderWindowInteractor()
renderWindowInteractor.SetRenderWindow(renderWindow)

# Begin Interaction
renderWindow.Render()
renderWindowInteractor.Start()