.mi Mental Ray file sizes?

[Bonedaddy]

Oh yeah, I'm using Maya, Win2k, and the renderfarm is Linux. I'm posting this here instead of Maya rendering because I know other packages have Mental Ray as well...

[gga]

Originally posted by Bonedaddy
Hey all,

For example: I have a 500k file with a 270 frame move, and when I export it to .mi (using ascii so that I can edit it and relink the pictures),


Do not use ascii, unless you are debugging stuff. Use binary. The binary format does not make all of the .mi file in binary. It still keeps all text readable and modifiable if that's what you need.
You can use good text editors like emacs or scripting languages like perl to change the text without effecting the file.
You can also use the MI_RAY_SUBSTITUTE environment variable for regular expression substitutions, without even opening the file.


I can always output one file/frame, but that gets even larger.
[/B]

That is traditionally the best way to do it. A render farm usually spits out a frame and then renders it, then removes the .mi file, without keeping all the .mi files of the sequence around.
The data transmitted may indeed be large, but if this is done automatically, you won't notice.


Why are .mi files so big? It seems to redefine everything for every single frame. Is there any way to cut down their size that I'm just not seeing? [/B]

Several things can make .mi files can end up being bigger than usual. For example, if you are passing tesselated polys instead of nurbs or subds. Hundreds of complex shading networks could also be an issue.
.mi files allow redefining only what changes from frame to frame, but it is up to the translator to take advantage of that feature. In scenes where you have animated geometry (characters, etc) the feature is not likely to help much or at all, but it can be mostly useful for sets and architectural walkthrus. I'm not sure if maya takes advantage of that.
Other than what I mentioned, you can try zipping/unzipping the .mi files before rendering with the stand-alone, but that's also mostly useful if you spit each frame individually, not if you spit out a single file.

[lazzhar]

Bonedaddy
I've tryed exporting to .MI from Maya but it seems it takes ages to finish the translation, and the file are big indeed.
I just did it for test but I'm wondering if it's the best way. I've in read other posts in Maya forum from someone who's working in a studio that they gave up the idea to export to .mi files cuz the time consumption so they just choosed rendering the Maya scenes.

Thanks gga, your posts are always appreciable.

[Saturn]

i don't know if the option is exposed in maya but you can do an incremental export.

According to the doc :
When on, only the first frame of the sequence is completely echoed. For subsequent frames, only the difference between the current frame and the last is echoed. When you echo MI2 files incrementally, they are output as a single large file.

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