vtk纹理能添加到指定位置吗，用vb实现，给个代码示例

当然可以！下面是一个使用VB.NET实现在指定位置添加vtk纹理的代码示例：

Imports Kitware.VTK

Module VtkTextureExample
    Sub Main()
        ' 创建一个球体作为几何体
        Dim sphereSource As New vtkSphereSource()
        sphereSource.SetRadius(1.0)
        sphereSource.SetThetaResolution(30)
        sphereSource.SetPhiResolution(30)

        ' 创建纹理映射坐标
        Dim tcoords As New vtkFloatArray()
        tcoords.SetNumberOfComponents(2)
        tcoords.SetName("Texture Coordinates")

        ' 添加纹理坐标到球体顶点数据中
        Dim numPoints As Integer = sphereSource.GetNumberOfPoints()
        For i As Integer = 0 To numPoints - 1
            Dim point As Double() = sphereSource.GetPoint(i)
            Dim phi As Double = Math.Atan2(point(1), point(0))
            Dim theta As Double = Math.Acos(point(2) / sphereSource.GetRadius())
            Dim s As Double = phi / (2 * Math.PI) + 0.5
            Dim t As Double = theta / Math.PI
            tcoords.InsertNextTuple2(s, t)
        Next

        ' 将纹理坐标附加到几何体的点数据中
        Dim points As vtkPoints = sphereSource.GetOutput().GetPoints()
        points.GetPointData().SetTCoords(tcoords)

        ' 创建一个vtkTexture对象并加载纹理图像
        Dim texture As New vtkTexture()
        texture.SetInputData(LoadTextureImage("texture.jpg"))

        ' 创建一个vtkPolyDataMapper对象来映射纹理坐标
        Dim mapper As New vtkPolyDataMapper()
        mapper.SetInputConnection(sphereSource.GetOutputPort())
        mapper.SetInputArrayToProcess(0, 0, 0, vtkDataObject.FIELD_ASSOCIATION_POINTS, "Texture Coordinates")

        ' 创建一个vtkActor对象并应用纹理
        Dim actor As New vtkActor()
        actor.SetMapper(mapper)
        actor.SetTexture(texture)

        ' 创建一个vtkRenderer并将actor添加到其中
        Dim renderer As New vtkRenderer()
        renderer.AddActor(actor)

        ' 创建一个vtkRenderWindow并设置渲染器
        Dim renderWindow As New vtkRenderWindow()
        renderWindow.AddRenderer(renderer)

        ' 创建一个vtkRenderWindowInteractor来显示窗口
        Dim interactor As New vtkRenderWindowInteractor()
        interactor.SetRenderWindow(renderWindow)

        ' 开始渲染和交互
        renderWindow.Render()
        interactor.Start()
    End Sub

    Function LoadTextureImage(ByVal filePath As String) As vtkImageData
        ' 使用vtkJPEGReader读取纹理图像文件
        Dim reader As New vtkJPEGReader()
        reader.SetFileName(filePath)
        reader.Update()

        ' 获取读取的图像数据
        Return reader.GetOutput()
    End Function
End Module

请确保将代码中的"texture.jpg"替换为您实际使用的纹理图像文件的路径。这个示例代码会创建一个球体，并将纹理图像加载为纹理，然后使用纹理坐标映射到球体上的指定位置。最后，通过vtkRenderWindowInteractor显示窗口并开始渲染和交互。