borisfx.com › support › documentationBoris FX | Sapphire Plug-ins for After Effects: Shake Center Bias: Default: 0, Range: 0 or greater. In Jumpy mode, adjusts the likelihood that each jump will reset the image to its original position. If set to zero, every jump is random. If set to one, every jump will go back to the center. Z Dist: Default: 1, Range: 0.001 or greater. Scales the 'distance' of the image.