If an object is deformed during an animation, only the last shape shows up.

Support Animation and Rigging
1

I am afraid the title is not clear enough. Let me explain.
Take a cube or cylinder and set key frame 1.
Then at frame 10, deform the object by selecting a vertex set and translating, rotating, scaling, extruding. Then set a key frame.
Repeat at frames, 20, 30, 40 with a different vertex set.
So we have the original shape at frame 1 and distorted shapes at the other frames.

Now if we play the animation (Alt+A), the altered shapes at frames 1,10,20,30 are not seen - they are lost.
Only the last shape (frame 40) is retained throughout the animation.

How can we get the animation to play the various shapes in their proper places?

[The actual problem refers to a character biting an apple as he walks. If the animation is played, only the last unbitten part of the apple is shown right through the animation, which is unacceptable]
Help will be much appreciated.

2

To keyframe the change to the mesh you need to use something like Shapekeys.

3

I think you’ve got it, Richard. Shape keys seem to the answer.
I did know know about them in Blender 2.5 but they seem much improved in 2.6
Thank you. And so prompt too.