Animation loop jerks even if perfect in Poser

Hi to all,

making a couple looping animation using Poser 7.
When uploaded, one of the figure has a jerk movement on the left arm when the loop restart the anim, like if the start and end of the anim had different poses.

In Poser frame 2 and last frame are identical (copied) and all runs good. I even opened the bvh and manually checked positions at frame 2 and the last frame. The second figure runs good inworld too.

Upload parameters in loop are 0 - 100% and don't understand why it has that annoying imperfection and how to solve it!

First of all, if you want your animation to be very, very smooth, you do not want frame 2 and the last frame to be identical. If you do that, your animation will appear to stop momentarily. Make the last frame identical to frame 2. Then make the next to last frame a keyframe and then delete the last frame. That will give you the smoothest loop possible.

However, that is probably not what is happening here. If it is a tiny movment over several frames, SL may be removing some of the movement altogether until it gets to the end. It then jumps back to the beginning and appears to jump.

Is it possible that you missed moving a joint? Maybe the collar? That would explain it as well, and it's an easy thing to miss.

Thank you for the tip, Cheree.

the problem is on the left arm: it moves hand, forearm, shoulder and collar as well during all the 5 seconds of the anim.

I'll try the trick of remake the last frame as you suggested and test it on beta grid

I thought there was also a problem with SL optimizing away slow movements.

Look very closely at that left collar to make sure you moved it. It sounds like you didn't move that joint.

Yes, Argent, there is. That is why SL may remove some tweened movements. The fix can be to move the joint more, or to use fewer frames per second. A large number of frames per second (like Poser's default 30) will often cause jerky movements. Lowering that number usually helps. What fps to use though depends on what your animation is doing. But 15 seems to be a good place to start. Some people use more, some less.

I suggest you check the animation graphs for the "jerky" arm - see if you can see a sudden jump in one or more graphs at the "jerky" frames. That way you can tell whether it is something in your animation or SL doing its infamous optimisation tricks.

I'll do the following things:
- redo last 2 frames for smoothest transition
- then checks left arm joint (but for now nothing strange appear in the graph, Deira)
- if again I'll try to lower the infamous framerate (now at 20 fps, for 5 seconds)

the strange is that only 1 arm of 1 figure did that. The other one is ok....
Question: should the optimization delete an entire frame or work at joint level too?

It is just possible that the jerk is caused by a movement of the abdomen or the chest - so I suggest you check those joints too, just to make sure. I can't think of anything else, other than re-time and re-test until you get a better result.

Thank you Osprey, I though it was a 'last frame' problem and not a 'first frame' one

For now i solved redoing the last 2 frames and adjusting manually some imperfection in other body parts...An now it seems finally good.

I'll try 'loop fix' next time it happens to me.



Update 22 august:

I successfully used BVHacker 1.5.2 loop fix to solve the first frame bug in a 360° rotation animation when looping. It added a new frame at the end copied from the second one and calculate the correct Loop In % to set in upload!

BVHacker is awesome.