Latent Space Walks

Lesson 3 of 11 · 7 min · Free, no account needed

What you will learn

Every code is a point in the latent space, and the decoder turns every point into a critter.
Interpolation walks from code A to code B: (1 − t) · A + t · B gives a real in-between critter, not a blend of two pictures.
A latent direction is an arrow that changes one feature, like fur, for any critter.
Far outside the cloud of training codes the decoder draws junk.

Start with a spiky critter. End with a fluffy one. What's halfway?
Tap the picture you expect.
Walk from A to B on the code map. Stop when the fur is exactly halfway.
The decoder draws the point you are on. Next to it: the two pictures simply blended.
The yellow arrow means more fur. Use it to make C fluffy.
Drag the arrow's round tail onto a critter. Its ears should stay the same.
The map of codes is the latent space.
Walks and arrows in it change critters smoothly.
Find a critter with long ears and spiky fur.
Drag the blue point. Stay inside the dashed cloud.
Which pins will decode to junk?
Tap all of them, then Check.
A decoder is trained only on codes of real critters. Codes far outside that cloud are places it never practised, so what it draws there is junk.
Math: put the dot a quarter of the way from a to b.
The point at t is (1 − t) · a + t · b, with t = 0.25.
Where does A + fur arrow land?
Tap P1, P2 or P3.
Adding an arrow to a code moves the point by the arrow: (−1 + 1.6, −1.5 + 1.2) = (0.6, −0.3). That is A with more fur.
Arrow golf: turn your critter into the target in as few moves as you can.
You start at the long-eared spiky critter you found. Each button moves 0.5 along one arrow.

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