Animate 2019.
layer.getZDepthAtFrame(FrameNumber)
FrameNumber :frame index An integer specifying the frame index starting from 0.
ZVal: An integer value that specifies the ZDepth value of the frame.
Method; An integer value that specifies the ZDepth value at the frame.
The following example gets the zdepth value at first frame of the first layer:
fl.getDocumentDOM().getTimeline().layers[0].getZDepthAtFrame(0)