Particles move around from frame to frame - when they shouldn't...

Support Animation and Rigging
1

I’m using particles to make a beard for a character that I’m animating. Problem is, the individual beard particles/stubbles move around from one animation frame to the next when I animate the character’s mouth.

I’m not sure whether it is one of the “random” buttons that I’m using both: one in the “Particles” tab (emit from), and the other in the “Particles Motion” tab (velocity). Needless to say these are static particles.

In the “Particles” tab (emit from), I have Verts, Faces, Rand and Even ON - in order to ensure a smooth and random beard distribution.

The only possibility I can think of is that one of the random settings is truly random: even from frame to frame, which causes the “jittering” effect on the beard.

If that is the case (it seems to be if I remove the “Rand” in the “Particles” tab and single step through the frames in Blnder. I am animating now as I type to verify).

The question is then: how do I get the beard evenly distributed, but not in nice “rows” (which one tends to get without the “Rand” on). I’m trying the Jitter table in the rendering.

Any ideas?

EDIT: Ok, it seems as if the jittering is caused by having BOTH random and even ON. If only one is on at a time, the jittering goes away. I need both ON. Does anybody know a workaround?

2

Switch oiff “Even” in the particle buttons.

It evenly distributes particles based on face sizes, and your faces are changing sizes as the fact animates.

Not an uncommon problem!

[Edit] - If you need a bit more randomness after that, Add a little random motion and life in the motion tab.

3

Thanks Ammusionist. That’s what I ended up doing, but then the hairs where obviously more dense in areas where the faces where smaller, so I had to tweak it a bit with weight painting.

I had hoped that the algorithm that calculates the “evenness” would not let the individual particles jump around so much from frame to frame… Fortunately, one can make it work with a bit of a workaround.