vrscene export with mayabatch

[xoy]

when i export vrscene file through backburner, it takes absurdly long with my files. interactive render('export to vrscene file' mode) in 'Render animation only in batch mode' finishes the same job way way faster. with my various data, export time goes so high as 40+ minutes. that's simply unacceptable. it finishes the job, but so unreasonably slowly. the same job finishes in a few minutes in interactive export. the problem is that i definitely need to use batch to queue up lots of render. in one of my simpler scene, export from maya UI took 30 seconds while batch export took 8~18 minutes per frame. i tried to kill all the references in the scene, optimize unused nodes and render layers etc. to no avail. can anyone explain why these two export mode show such drastic difference? could there be other ways to generate vrscene files fast and reliably? please advise me. thanks in advance.

[t.petrov]

Can you send us the scene?
What version of Maya, V-Ray and OS do you use?

[xoy]

maya 2012 sp2, vray 2.20.01 and windows7. all 64bit. i'm not sure how i should prepare my file to be meaningful for you. obviously it can't go with all the reference and animation cache and textures. then again, without them i'm afraid that the test would have less meaning. anyway, i'll send you one sample. thanks.

[xoy]

petrov,

i sent you my sample file. i hope you can read it without too much trouble. i do suspect a lot of messy structuring is going on my part. it just sems that it doesn't explain enough. my sample contains maya hair, which affects all processes significantly. the "pre-render export" is obviously the time killer as another person on this board explains his case with maya nhair at this moment. funny thing is even when he hair is hidden or not included in the render layer, the export time and pre-render stage is affected as long as the data is somewhere in the file. when i totally unload the reference or delete them, it can go quick. i don't think it's only the hair though. any animation data slows down the process. well it should, but it shouldn't this much. local export from UI doesn't show that mysterious "Pre-render export" message. it appears that it goes directly to exporting stage instead.