I could not find a solution to the issue that I am experiencing, so I am posting it here.
I have created a null layer, made it 3D and applied the wiggler to it to give it a random motion in all directions. Then I made some objects follow the null layer.
The problem occurs when I create a set of cameras. (I need to have multiple cameras for different shots. Working with keyframes on a single camera gives me sometimes uncontrollabe jumpy movements.)
With one camera in the comp everything is as expected, but as soon as I create a second camera or split the current one the animation of the null layer changes. With every camera that I create not only does the result of the wiggler change, but it also becomes shorter (or faster).
How can I tell AE to keep the result of the wiggler no matter how many cameras I have in the comp?
1) The other cameras, having different positions, have different views of the same wiggle. If one camera is closer than another, the same wiggle will naturally seem more severe.
2) You are using a wiggle() expression, and adding new layers above the layer with wiggle is changing its index, which changes its random seed, which changes the results. Add the new cameras below the wiggled layer to avoid this outcome.
Thank you for pointing me in the right direction! It was the random seed with the index changing.
Is there a way to bake the result of the Wiggler into keyframes to avoid the random seeding? The wiggle() expression can be converted into keframes, but the Wiggler doesn't allow this. I guess, it is because it already gives keyframes, but at the same time it operates with expressions.