How to rotate the 3d camera around a center ruler or 3dvector

Development
1

the basic camera action is Yaw,Azimuth,Elevation,is it possible to rotate camera around like vector line [2,1,3]?

2

use vtkTransform can do it

    transform_node = self.camera_node.GetParentTransformNode()
    if not transform_node:
      transform_node = util.AddNewNodeByNameByClass("vtkMRMLLinearTransformNode")
      self.camera_node.SetAndObserveTransformNodeID(transform_node.GetID())
      transform_node = self.camera_node.GetParentTransformNode()

    modelToParentTransform = vtk.vtkMatrix4x4()
    handleToWorldMatrix = vtk.vtkTransform()
    handleToWorldMatrix.PostMultiply()
    handleToWorldMatrix.Translate(-self.focus_point[0], -self.focus_point[1], -self.focus_point[2])
    handleToWorldMatrix.RotateWXYZ(val,self.cemera_vector_normalized)
    handleToWorldMatrix.Translate(self.focus_point)
    modelToParentTransform.DeepCopy(handleToWorldMatrix.GetMatrix())
    transform_node.SetMatrixTransformToParent(modelToParentTransform)