Vray: Query if renderView window is rendering

[paynter3d]

so i'm trying to batch render icons for a shader library.

my script searches through a specified location and finds any maya file without an image associated with it, and then imports that file(a shader) into a render scene, assigns imported shader, and renders using mel.eval('renderWindowRenderCamera render renderView renderCam')

when render is done it saves image to location of shader file. The problem I am having is specific to vray. Since rendering in maya with vray allows you to continue working, the save image part of my script is executing right after render starts, before render is finished. In mental ray it won't execute until render is finished.

Any ideas to deal with this? I haven't found a way to query if render is done before moving on. Thanks in advance

Erik