Sunday, January 23, 2011

File Referencing for Maya

I've had a few people ask me questions about file referencing so here are some resources to help you.
Let me also point out that it is not 100% necessary at this stage. You can just open your rig and start animating. But if you do want to try referencing, one simple way is to save the rig in the same file as your animation so that it's always where you need it. If you take the file to a new location, you need to relink the references next time you open the scene.  It's an extra layer of complexity but one you'd be wise to get comfortable with as it is very standard on big productions.


Here's a nice, clear explanation of file referencing for Maya:
http://www.3dfiggins.com/writeups/mayaReference/

There's also a complete explanation on the Autodesk help site. Maybe a bit more information than you bargained for!:
http://download.autodesk.com/us/maya/2010help/index.html?url=File_referencing_File_referencing_tips.htm,topicNumber=d0e123330

Both small and large-scale independent and commercial productions I've worked on used referencing to keep file sizes small, protect assets, allow for updates mid-production, and ease work flow with teams of freelancers.  For example, often animation starts before the models are 100% finished. Animators reference in their assets from a standard location set by the production. Meanwhile, the modeling and rigging team may be making tweaks to the assets.  When a new update is ready for production, it replaces its predecessor, and the animators scenes will open with the new asset. As long as the asset's naming conventions (both the file name and the various nodes within it) remain constant, you can swap in changes at any stage of production.

If anyone renames, adds or subtracts nodes, or moves parts of the set, well, that can be a major problem for the animation team. Picture animators coming to work, opening a scene, and their characters are walking along a path that is now 10 feet to the left. Or their knees are now backwards. Or the animation is gone except for the left foot. Yup. It happens. So backing up ALL the previous versions of rigs, sets, etc, is VERY important. If something breaks, you can always revert to an older, working version.

Animators can screw things up too.  If, as on some productions, you are allow to port assets to another location, as in the case of freelancers working from home, you must take care to reference the files exactly the same way or fix it when you return the finished file. For example, if you reference a file from "M:\bobsmovie\rigs" and then at home you have your rigs stored at "D:\thismoviesucks\rigs", the following will happen when you hand in your file:
(a) your references will be broken, ie, your scene will be empty
(b) the reference path you set up at home will be visible & will need to be fixed by someone
(c) people will not be very happy with you

So understanding file referencing is VERY important. :o)
Any questions? Please don't hesitate to ask!

2 comments:

  1. Question:
    Could I just use a non-rigged version of max file? (I want to do one in maya and 3d max)

    Because I don't really understand the rigs for 3d max, when I move the ball to the right the ball gets some sort of noise modifier amplification. (for 3d max)


    A:
    Yes, feel free to just use a basic primitive and key the geo. If you know how to add squash & stretch using a modifier you can do that near
    the end. Be sure to control it with enough keys so that the ball only squashes on contact, etc.

    For the rigged versions, be sure you are only grabbing the ctrl obj for transl/rotate & not the geo as well, or the squash ctrl, or else
    it will multiply their effect. Lock out the geo to prevent it being selected. In Max, freeze it, in Maya, limit your selection to curves
    only (top toolbar). Or, make a layer for the geo & set it to reference only.

    This is a great opportunity to experiment and learn what works & doesn't... Often we learn more through the latter..

    ReplyDelete
  2. Question: Re: ma and mb file system for maya, which one is the one I can change again?

    And could you refresh me or point me to a resource that demonstrate the reference file system so I only mess with the rig in maya.

    A:
    It's the .ma files that you can change.
    If you find this at all confusing, it's perfectly ok just to open the rig and start animating.

    I just wanted to introduce the concept of referencing as it's very standard but not well understood by people new to production.

    .ma files are usually MUCH larger than .mb files, but that won't matter for what we're doing. For example, the .ma of Bolts is 42 MB while the .mb is only 22. But /ma's have some advantages. You can just open the scene in any word program, like Notepad. You can read it and potentially troubleshoot it, such as renaming objects. Another is that you might be able to open it in an older version of Maya by opening the ascii file in notepad and swapping the version numbers.

    Hope that helps.

    Thanks for your question!

    ReplyDelete