Houdini 20.0 Nodes VOP nodes

Bump Noise VOP node

Displaces surfaces along their normal using anti-aliased noise, and returns the displaced surface position, normal, and displacement amount.

This operator displaces surfaces along their normal using anti-aliased noise, and returns the displaced surface position (dispP), normal (dispN), and displacement amount (amount).

Optionally, the noise amplitude can be clamped to a specified range. The clamping is done smoothly using a cubic interpolator. If a rolloff is specified, the inflection point of the blend will be shifted. If the rolloff is greater than 1, the shift will be to the right. If the rolloff is less than 1 (and greater than 0), the shift will be to the left.

For a denser noise, enable Compute Absolute Noise Value. The absolute value is computed before any clamping takes place.

Typically, this operator will be used in a displacement shader, with both outputs piped into the corresponding inputs of the Output Variables operator. Alternatively, it can be appear in a surface shader, in which case the displaced normal would be normalized and then connected to the nN input of the Lighting Model operator.

If the Surface Position (P) input is not connected, the global variable by the same name will be used instead. Typically, you will use Rest Position or UV Space Change as P inputs. If you do need P, you will find it in the Global Variables operator. The input normal (nN) should be normalized if explicitly connected. Usually, you will not need to touch nN unless you want to apply an additional displacement using an operator like Bump Map.

Use this operator to generate a wide variety of patterns, from plateau landscape and mountain ranges to crumpled paper, stucco and cork. For example, a frequency of 7.2 with a height of 0.09 will yield a stucco-like pattern if clamped between 0.05 and 0.43.

See also

VOP nodes