How do I animate a single face of a mesh?

Question

I have my mesh which began as a plane and which I have extruded along the z-axis so it looks like a simple narrow block. I've edited the mesh to take the shape of a country with numerous states. In my animation I would like each of states to 'grow' upward from the plane along the z-axis. I've tried placing the object in its initial location at frame 1 and adding the first keyframe, moving to frame 72, extruding and individual state along the z-axis and inserting the second keyframe but this doesn't work. When I go to play the animation the extrusion doesn't return to its initial state at frame 1 and no animation occurs.

Any help is appreciated, thanks.

Answer 1

You cannot keyframe vertices directly, but several possibilities to do that.

For instance:

• Using an armature:

Create an armature, create bones in it and assign the wanted names to the bones (ie states names), in the map assign the wanted vertices to groups which are named the same way. Parent the map to the armature using 'with empty groups' option (as the groups are already created).

pros/cons: can grab, rotate, scale the parented group as you wish

• Using a shrinkwrap:

Add a shrinkwrap modifier which applies on a vertex group. Here you can animate the plane target use in the shrinkwrap.

pros/cons: fast to do but static: only up and down movements

• Using shapekeys:

Add a base shapekey, then a second one and this last selected, move the vertices to the target place you want. Now you can animate the shape key.

pros/cons: you can place the vertices exactly where you need, but static once done

• Using scale:

Here, simply separate the country or state you want and play with its scale.

pros/cons: only for up/down movements

Edit:

• Using a hook:

In edit mode, select the vertices you want and CtrlH to hook them:

pros/cons: nearly like bone here: grab, rotate, scale the hooked vertices (or group) as you wish

• Using a lattice

Again with a vertex group but here with the lattice modifier.

pros/cons: not the simplest to setup but can grab and scale too.