【MAYA】【求助】Maya Arnold渲染摄像机bookmark的问题

import arnold as ar
import maya.cmds as mc
import maya.mel as mm
cView = mc.getPanel(wf=1)
cCam = mc.modelEditor(cView,q=1, camera=1)
camViews = mc.ls(typ=*cameraView*)
camHistory= mc.listHistory(cCam)
bookmarks= [i for i in camViews if i in camHistory]
for each in bookmarks:
mc.cameraView(each,e=1,camera=cCam,setCamera=1)
mm.eval(*renderIntoNewWindow render;*)
#for Arnold only
while ar.AiRendering()==1:
continue
else:
mm.eval(*renderWindowMenuCommand keepImageInRenderView renderView;*)

没具体试过，不过 ar.AiRendering()这个方法第一次见
这个是怎么调用的？没看到mtoa的文档里面有写MEL的相关接口的信息啊