If you’ve tried to open a Maya 2011 .mb or .ma file in a previous version, most likely you have lost a lot of information. At first glance its scary because you only have the outlines of your models, even in shaded mode. Its easy to think you’ve lost all your polygons. Also, a lot of connections, like expressions, are lost.
Don’t worry, I’ve come up with a solution. Here at work, we have an older non-intel Mac which can’t handle Maya 2011, so we do a lot of cross-version stuff. It got to the point where I had to come up with a solution. And here it is.
This will require a text editor of your choice, and the Maya 2011 file saved as a .ma, or a Maya ASCII file.
Open up the .ma in the text editor (depending on how big the scene file is, this could take a while). Use the find function in your editor to locate “relationship”. Keep find next-ing it until you come to the very last line that has “relationship” on it. It should be something like “relationship “shadowlink” … ” You’ll also notice the previous few lines start with “relationship”.
Select these lines and delete them. If you’re tech savvy, you can write a script that will find and replace these lines in multiple files. The problem is, pre-Maya 2011, there is no “relationship” procedure. When Maya is reading the .ma, it stops at “relationship”. However, after “relationship”, is a lot of valuable information, like connections. So with these lines gone, Maya continues to read the file and hooks up all the connections, preserving your materials, expressions, and more.
Open it in an older Maya version and everything should be fine. You’ll notice in the script error, depending on how big your scene file is, a lot of errors saying the same thing for each object you have, something along the lines of an invalid name of attribute. These can generally be ignored. Your files should be fine.
However, if you have things like Animation layers which aren’t included in older Maya versions, you might get some other weird errors and loss of information, but this can’t be avoided.