vtk 屏蔽鼠标交互事件

在使用vtk的时候，鼠标会默认响应一些事件，比如MouseWheelBackward时，actor缩小，MouseWheelForward时，actor放大；MouseMove时，actor会随之旋转等等。

如下我们创建了一个cyliner，使用鼠标交互：

如何将这些默认事件屏蔽呢，参考了vtk的python的用户交互demo和网上的一些资料，发现vtkInteractorStyleTrackballCamera这个类具有鼠标交互的方法和属性，废话就不多说了，结合C#版本，

看一下这个类的定义：

 相当于移动camera，屏幕上的actor会进行响应对应的事件。

直接上代码：

#!/usr/bin/env python
# This simple example shows how to do basic rendering and pipeline
# creation.

import vtk

class  MouseInteractorHighLightActor(vtk.vtkInteractorStyleTrackballCamera):
    def __init__(self, parent = None):
               
        self.AddObserver("MouseMoveEvent", self.MouseMoveEvent)
       
        self.AddObserver("MouseWheelForwardEvent", self.MouseWheelForwardEvent)
      
        self.AddObserver("MouseWheelBackwardEvent", self.MouseWheelBackwardEvent)

    def MouseMoveEvent(self, obj, event):
        pass

    def MouseWheelBackwardEvent(self, obj, event):
        pass

    def MouseWheelForwardEvent(self, obj, event):
        pass

def main():
    colors = vtk.vtkNamedColors()
    # Set the background color.
    bkg = map(lambda x: x / 255.0, [26, 51, 102, 255])
    colors.SetColor("BkgColor", *bkg)

    # This creates a polygonal cylinder model with eight circumferential
    # facets.
    cylinder = vtk.vtkCylinderSource()
    cylinder.SetResolution(8)
    
    # The mapper is responsible for pushing the geometry into the graphics
    # library. It may also do color mapping, if scalars or other
    # attributes are defined.
    cylinderMapper = vtk.vtkPolyDataMapper()
    cylinderMapper.SetInputConnection(cylinder.GetOutputPort())
    
    # The actor is a grouping mechanism: besides the geometry (mapper), it
    # also has a property, transformation matrix, and/or texture map.
    # Here we set its color and rotate it -22.5 degrees.
    cylinderActor = vtk.vtkActor()
    cylinderActor.SetMapper(cylinderMapper)
    cylinderActor.GetProperty().SetColor(colors.GetColor3d("red"))
    cylinderActor.RotateX(30.0)
    cylinderActor.RotateY(-45.0)

    # Create the graphics structure. The renderer renders into the render
    # window. The render window interactor captures mouse events and will
    # perform appropriate camera or actor manipulation depending on the
    # nature of the events.
    ren = vtk.vtkRenderer()
    renWin = vtk.vtkRenderWindow()
    renWin.AddRenderer(ren)
    iren = vtk.vtkRenderWindowInteractor()
    iren.SetRenderWindow(renWin)

    # add the custom style
    style = MouseInteractorHighLightActor()
    style.SetDefaultRenderer(ren)
    iren.SetInteractorStyle(style)

    # Add the actors to the renderer, set the background and size
    ren.AddActor(cylinderActor)
    ren.SetBackground(colors.GetColor3d("BkgColor"))
    renWin.SetSize(300, 300)
    renWin.SetWindowName('Cylinder')

    # This allows the interactor to initalize itself. It has to be
    # called before an event loop.
    iren.Initialize()

    # We'll zoom in a little by accessing the camera and invoking a "Zoom"
    # method on it.
    ren.ResetCamera()
    ren.GetActiveCamera().Zoom(1.5)
    renWin.Render()

    # Start the event loop.
    iren.Start()

if __name__ == '__main__':
    main()

效果如下：

vtk 的python版本的User Interaction的Demo的链接如：https://lorensen.github.io/VTKExamples/site/Python/  

camera基本原理参考：https://blog.csdn.net/wzheng92/article/details/79935059