up vector decided to change on it's own?!

[minilogoguy18]

I have a rig that I built and all the sudden the right knee bends backwards even though NOTHING was changed and unfortunately it happened before I last saved. changing the resolution plane is not an option at this point as it will just ruin the enveloped model.

Does anyone know what could have happened and how to fix it?

[SpookyMunky]

hmm, cant you just remove all constraints from whatever bone is afflicted ? then maybe if arranging it back into the right position is out of the question, put a null where you think the upvector should be and do the constraint again with constraint compensation on ? .. if that doesnt work send me the scene, sounds fun

[csaez]

Referenced model? If so try cleaning up the delta or save/load animation in a new ref model.

[minilogoguy18]

The scene is a Mod Tool 7.5 .exp file, don't know if you have Mod Tool SpookyMunky.

I have no idea how this happened, it doesn't make any sense. It wouldn't be bad if I could just change the resolution plane but nothing I have tried to preserve the envelopes has worked so far. I really don't feel like redoing it.

[EricTRocks]

You can change the roll parameter to rotate it back around to the correct side. Then select the deformers for the leg and go to Animate > Deform > Envelope > Set Reference Pose.

[mattmos]

Have you messed about with the kinematic joint preferences for the second bone in the chain yet? Might be worth a fiddle. If you invert the angle set in the preferred rotation then move the leg it should click back to the normal (non-inverted) direction.

[minilogoguy18]

Thanks for all the fast replies guys, gonna try some of the things suggested when I get home from work. The odd thing is I do have an old save containing an animation and comparing the 2 nothing is different with that leg or any of its constraints. I just don't wanna have to redo all the changes since that old file but the leg at least works right.

[minilogoguy18]

Have you messed about with the kinematic joint preferences for the second bone in the chain yet? Might be worth a fiddle. If you invert the angle set in the preferred rotation then move the leg it should click back to the normal (non-inverted) direction.

That worked perfectly, not sure if it somehow got changed but I also was focusing so much on the first bone (thigh) since it's resolution plane is normally what would have the most influence on up vector.

The set reference pose is another thing to remember, seems like that one is something I should know by now, will help with touching up the weights since I changed the base pose to something a little more suited for the game engine, fingers being in the base pose rather than straight.

[mattmos]

It happens sometimes when the leg is created without enough bend between first and second bones, and also sometimes when you accidentally translate a bone, don't ask me why that affects it though!