VaM 1.x Timeline glitch - random nodes flipping 360 degrees?

[Buzz]

Has anyone else experienced a new problem in timeline where a random node spins 360, then spins back for no reason? Seems to happen in between set points when the animation is run. Stepping through the timeline - it doesn't happen.

Happened on a scene I made from scratch on one of the person atoms. Been working on the scene over multiple sessions. Several working animations. Then out of the blue, the hip node and the neck node starts flip-flopping for no reason in the middle of a timeline. Save and exit, restart VaM, problem is still there, same nodes, same spot in the timeline (in between programmed points). Had to essentially delete set points before and after the bad section and then the problem went away.

Thought it was something to do with my specific scene, but later opened a scene from the hub, added a new animation to an existing person atom, added a few set points, ran it, and their chest node has the same flip-flop!

I *LOVE* timeline - hope someone can tell me how to prevent or fix this!

 

[jp63]

I have an issue in timeline right now that might be related. All of a sudden I can't do hand animations. Hand starts to rotate between timeframes. Did you figure out what the problem was?

 

[hazmhox]

If a node flips back or does a sudden weird rotation, it's probably due to some kind of gimbal lock situation or extreme angle rotation.

If you prefer, imagine your three X/Y/Z axis for your hand, it's expected to have a neutral position. From that neutral position, the rotation is limited to a certain degree (like your bones in real life). From there, the system tries to be clever, if your rotation exceeds "physically correct" angles, it will try to flip the other way around... but in this situation, it is really hard to be fail proof and ensure a proper transition.

When can this happen :

• When an animation A transitioning into an animation B has very big differences in rotation ( for instance, hand rotated 180° )
• When a rotation loop resolves (loops back) during an extreme rotation and tries to realign the control node

To limit this you can:

• Ensure you don't go too often in extreme rotation situations
• Ensure your animation have proper loops
• Configure your animations to let them finish before transitioning ( preserve length option )
• etc...

 

[Buzz]

Thank you Hazmhox. That all makes sense.

To try to eliminate the flipping, I set the flipping nodes to Comply, and let then settle into position, and then set that position in the timeline. I made sure there weren’t any extra steps (for this animation, steps are 1s apart.) Still had the flip-spin. I deleted all the offending node steps, and re-built them in the timeline and the problem went away, so I’m still not clear what was happening, but brute force fixed it!

Jp, your had flips might be the same issue, so you may also need to bite the bullet and rebuild the animation.

I did also consider trying to find the offending coordinate/rotating points in the JSON file, but timeline now stores that data in hexidecimal, so nope!