Provides bump mapping based on a 2d texture map. Note that bump mapping does not alter the geometry of the object, it only changes shading normals so that things won't look right in silhouette; however, very often this does not matter. The bump2d node evaluates the bump function at three locations with an offset in u and v from the shading point, via a "forward differencing" algorithm.
Keep in mind that the object will need UV coordinates that will be used to derive the perturbation.
Noise map connected to Bump 2D which is connected to the Normal parameter of Standard Surface
This allows you to scale the height of the bump map output.
The input used to compute the normal perturbation, provided as a float value representing the height, or directly as an RGB texture map, in which case the first component (R) will be used.
When linked, this attribute will be used as the normal that will get bumped. It can be used to chain multiple normal adjustments (normal maps, bumps, etc).