Rorsdors, before discussion of firewall keys, as long as we are speaking of safety, might I just re-mention incrementals. That means that you save your pz3 out to a new sequential number often? Just stop work once in a while, hit 'SAVE', then go back in and hit "SAVE AS" and save as the next increment. I am working on an animation with a rhino in it now, so rhino01.pz3, rhino02.pz3, etc. That haveing been said, in a long animation you can place a 'firewall' between one section and another. The main reason to do so is that you do not wish changes (especially 'spline' changes) on one side of the wall to affect anything on the other. The way I do it is simply to select two frames completely up and down all elements and mark them 'constant'. The easiest way to select all is to "fold up" all elements by closing the down-pointing triangles into side-pointing. This collapes everything. Then select by clicking on the first element of a frame, shift-click on the last of the next frame. Hit the 'constant' button. ::::: Opera :::::