View Full Version : mirror, export weight maps

06 June 2003, 04:55 PM
question about mirroring and exporting weight maps in maya.

first of all, none of it seems to function without uv mapping assigned (at least the export) - so i got that part.

when i mirror weights, and i have influence objects, like half of a body and a bicep muscle on each arm, the mirroring does not work correctly. when i mirror the weights, it assigns the mirrored weight to the first influence muscle. so now, when i flex the right arm, the bicep in the left bulges also. am i doing this wrong, or do influence objects just not mirror correctly?

was playing around with the export weights. this function does not work at all unless uv mapping is assigned, so i got that part finally. but, when i export weights, move a few vertices around on the mesh just a bit (as a test), and then import the weights, it does not work correctly. what ends up happening is that the weights come in very close to correct, but a very tiny weight of about .002 is assigned to every damn joint on top of whatever the original weights were. sometimes worse. so then i have to do a prune weights and re tweak things.

so basically, at this point i am fed up with both of these tools because they do not appear to work correctly. does anybody know of any trick or step that i might be missing, or will i just have to forget mirroring and exporting weights?

using maya 4.5 btw if that matters

thanks in advance for any help

06 June 2003, 06:52 PM
boo, i have no problem with mine. i am pretty suer its your work method. you should do this. i learned thsi from my gnomon dvds. weight half the body
then mirror.
then check to make sure everythign worked properly

everynow and then like my characters jaw will have like 1 or 2 verts not weights properly

do that make shure your character is all weighted first. then add your influence objects. i dont know what you use for influence objects, but i use Clusters, i think there really fast.

then if you want you can export your weight maps. it will work fine then. then once everything is weighted you know add your Inf objects and that should do it. thats how i work , i never have had problems. maybe this helps? but i just belive its how your work method is .

06 June 2003, 08:19 PM
The Mirror weights utility in Maya finds bones on the opposite site by position, not name. So if you have multiple influences in the same place, the mirrored weights will be screwed up. To get around this, we wrote our own internal mirror utility in MEL that steps through all the vertices on the left, finds its match on the right, looks up the bones/influences for the left point, goes through the influences and replaces L_ with R_ or left_ with right_, etc, and then assigns the correct weights. This works out much better than the built in Maya mirror for our rigs.

The save/load weight utility in Maya is also pretty much crap when it comes to production. It requires that your model be UV-mapped to a bitmap, and then it writes out a bitmap for every influence in your skin cluster. You have to have a sizeable bitmap to get the resolution you need, and it generates a ton of bitmaps. It is also very slow. A much better approach is to go to and find the saveWeights.mel script that Big Idea released a while back. This script writes vertex weights out to its own file format, and then reads them back on the new geometry. You can save/restore weights either by point order or by global/local position. Very, very useful utility.

Hope this helps,
Michael Duffy

06 June 2003, 05:44 AM
I did both a Google search plus searched Highend and could find no "saveWeights.mel" script. If you have a url or something it would be great.


olivier georges
06 June 2003, 07:25 AM
here :


06 June 2003, 12:34 AM
Thanks....but that link only takes me to the mel scripts section on Highend. Then when you do a search for the script "saveWeights.mel" it comes back saying it couldn't find it. But it's there in the animation section. I got it... thanks Oliver
Very odd web site that Highend.


06 June 2003, 12:55 AM
im sure im just using it wrong, but highend has the weirdest search i have ever used. like i said im sure im jus using it wrong?

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