Move the light.

Change what you see. Discover what stays the same.

Two flat surfacesShared light
Without a normal mapUniform directions
With a normal mapDirections vary across the surface
35°

Drag across either image, or use the slider and arrow keys.

The depth is in the shading.

Both surfaces are flat. As you move the light, the mapped directions reveal grooves that aren't in the geometry. Try looking from the side.