class_docstr: Class to support multiple render passes for a renderer.
  
  Notes
  -----
  Passes are organized here as "primary" (vtkOpenGLRenderPass) that act
  within the renderer and "post-processing" (vtkImageProcessingPass) passes,
  which act on the image generated from the renderer.
  
  The primary passes are added as part of a vtk.vtkRenderPassCollection or
  are "stacked", while the post-processing passes are added as a final pass
  to the rendered image.
  
  Parameters
  ----------
  renderer : vtk.vtkRenderer
      Renderer to initialize render passes for.
docstr: Initialize render passes.
docstr_tok: ["Initialize","render","passes","."]
code: def __init__(self, renderer):
      """Initialize render passes."""
      self._renderer_ref = weakref.ref(renderer)
  
      self._passes = {}
      self._fxaa_pass = None
      self._shadow_map_pass = None
      self._edl_pass = None
      self._dof_pass = None
      self._ssaa_pass = None
      self._ssao_pass = None
      self._blur_passes = []
      self.__pass_collection = None
      self.__seq_pass = None
      self.__camera_pass = None
  
imports: import weakref
  from .None import _vtk
label_desc: Use image node_id 1 to create a new RenderPasses object  with example: obj = RenderPasses(renderer)