Particles Jerk

I am using a mesh group as the particles in my animation. The problem is that sometimes the particles “jerk” when I hit play. Every 11th frame the particle rotates -68 degrees around the Z axis. Over the next 10 frames the particle gradually rotates back to it’s original direction, then on the 11th it jerks back to -68 degrees again.

Hoverer sometimes it works fine and the particles do not jerk. Is there any way to fix this or is it a bug that the developers need to work on?

did you change the cache step in
properties;particles;cache. the default is 10 (this means it will only “record” the particles location and rotation on every 10th frame) now this is fine for things such as flames, or fast moving particles with no collision. however personally i use settings of 1 2 or 3 to get a more accurate bake of particle motion, although the size of the cache will, of course, be much larger.

I first encountered this problem when trying to use fluid particles, they would hit a collision surface and “wobble” back and forth in a sine-wave motion through the collision object the were “resting on” because of the interpolation used when the particles are relocated.

now I’m not 100% sure this is the same problem you are having, but it could cause similar results. (but with rotation being interpolated rather than location)
its worth checking, at the very least.

Yes, thank you. I just changed the Cache Step down to 1 and rebaked it. The particles work fine now.