LC #42 Pipers Alley

View Full Version : negative joint translation values

08-28-2005, 03:43 PM

Just reasing some David Walden scripts and he seems to have a problem with
joints having negative transform values. As you might know--maya mirror with
behavior checked will create negative transform vals on the mirrored joints..Any one
have a thought on this???thanks...Paul

08-28-2005, 10:46 PM
I'm sorry, but whats the problem?


08-29-2005, 03:33 PM
eh? that was my question....I don't see any problem with it... Maybe I'll write David Walden and find out what he was thiniking!

08-29-2005, 05:32 PM
There's nothing wrong with having negative transform values. This happens in order for the behavior of the joints to be mirrored, like you said.

08-29-2005, 05:43 PM
Sorry, I was a Maya user, and now I am a XSI user.
Anyways, I am using XSI to do the mirror control like the way which Maya do, and it creates a negative scaling value in the joint which has no problem if you are animating it in XSI. Once the character with negative scaling value in FilmBox, it will scew up.... the joint filp and never go back to normal...
I am wondering will it happen to the Maya character?

08-30-2005, 03:41 PM
I believe I tested my character in mb and it worked--I'll double check and post

08-30-2005, 03:53 PM
Mpoon, I'm not sure if this is what you're asking, but the mirror joint command in Maya doesn't give you a negative scale value like XSI does. It just orients each joint's LRA in the opposite direction and translates the mirrored joint along negative X instead of positive X like the original side.

08-30-2005, 05:20 PM

Use Maya's orient joint tool (or Mike Comet's, quite a bit better) and orient the joints until their translate.x is positive.

The t.x needs to be positive for the stretch on the joints (even if you're not using it).

This comes from David Walden himself, as I was having the same problem you were.

08-30-2005, 06:15 PM
I had the problem even the bone doesn't has negative scaling value, but its parent or somewhere above, the bones will filp...

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