Why cant I use extrusion as a shape Key?

Im trying to animate an object, and I want to extrude object as part of the animation.

I tried using shape keys but I can only Translate, Rotate, Or scale vertices of the mesh.

Thanks

Why cant I use extrusion as a shape Key?
Because you are creating new vertices.

May I suggest that you might want to extrude them first, but not offset (which makes selecting them tough). Next use copy location to an empty and animate that, or make shapes and animate their influence…

Topology cannot be animated with current tech, because while it may seem simple in some cases the logic that would be needed for the program to do that with enough predictability would be very complicated.

" May I suggest that you might want to extrude them first, but not offset" This works for me but i would just add a shape key

Can´t I just pick a face of a box and extrude it i a direction?

shapekeys do not allow to change the mesh topology. this is due to the mathematical representation of meshes and the underlying topology of manyfolds…
however, in most cases there are plenty of workarounds which have to apply to the particular problem. so, there is no general solution but custom solutions for particular mesh topologies.
what is your particular problem? maybe we find a way to solve it :slight_smile:

regards,
serum

If you go with the ‘extruded but not offset’ approach, you can make the new vertices easier to select using vertex groups.

Also, to reset them after extrusion: the magnet tool.