strange ipo curve

I’m animating layers. Moving something from layer 2 to layer 20 after 25 frames. I did it and it works, but when I look at the ipo curve it’s not a single line going across then jogging to level 20. It’s a single line until the move takes place then it breaks and becomes two parallel lines moving across. Both of the parallel lines have the yellow dot for a keyframe at the beginning and both at frame 25. I animated them by inserting keyframes at 1 and 25 then going back and changing the values in the numerical window. The animation works, I would just like to know what I’m looking at here.
Thanks

In the IPO window, look at the menu Curve/Interpolation mode. It’s probably on Constant instead of Linear or Bezier. This is useful if you want things changing in sudden steps, like layer visibility.

The IPOs for layers aren’t a good indicator. Layers have multiple values whereas the IPO can only show 1 value for a particular point in time. In short, don’t use the IPO window. It’ll give you a headache!

I just go to the frame I want, set the layer (Mkey) and hit “I” to insert a keyframe, and hit “Layer” in the menu.

I’ve never animated layers, but I just looked at it and it seems fairly obvious (to me anyway :slight_smile: )what it’s doing.

It puts a curve (line) at the Y value corresponding to the layer number.

You’ll only get two parellel lines if you choose/keyframe more than one layer at a time for the object, otherwise for a single keyed layer, you should see a yellow dot at whatever frame the layer is keyframed to become visible, with any previously keyframed layer’s IPO curve ending at the point of the new keyframe.

Mike

I don’t understand whay you mean by “layers have multiple values”.

See my previous post for the explanation of what happens in the IPO window.

MIke

Thanks to the clues above I think I know whats going on. Instead of going to layer 20, it was going to layer 3 AND 5. I still don’t know why. I erased the curve and re-did it by the I key and M key method. It looks fine now. Although it took me a few tries to learn I need to go to layer 20 and select it again to insert the second key, (or just make layer 20 temporarily visible).