How to cut Sushi in 3d

I've been asked a few times how I did the 'sushi cutting' in the animation above so I will try to explain. It's all slight of hand. What your looking at is 3 versions of the same piece of "sushi".

Sushi #1:
First I designed the sushi halves and placed them on top of each other. They almost form a cube. I put each half into their own separate 'null object' to make animating them separately easier later.

Sushi #2:
Then I put them together and combined the outer skin into a single cube mesh. I make sure to keep everything in the same place by putting all my work into a 'null object'.

Sushi #3:
I take Sushi #2 and duplicate it, then add cuts into the mesh which add the tearing effect when the Sushi, overall, is stretched.

I use the same 'deformer object' on all versions of the Sushi to animate the stretching of the sushi. Animating the null I can move them together and jump between animations to create the tear effect.

I hope this helps someone.