Bump2d - Arnold User Guide

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.

Bump Map

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.

Bump Height

This allows you to scale the height of the bump map output.

Normal

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).

Bump2d will work with Pref even when the object does not have UV coordinates. Bump2d will create a frame of reference if no UVs are present to compute the offsets applied to P.