Map Random

Single-purpose mapping node that emits a stable random value per internode, seeded by attributes you choose. The randomization step in a Map chain.

Marked experimental in the Houdini node title. Behaviour and parameters may shift.

Map Random is the randomization step in a Mapping chain. It emits a stable random value per internode, seeded by attributes you choose, so the same internode receives the same random value across cooks. Used to introduce organic irregularity into otherwise uniform parameters like Width, Pitch, fork probability, and decoration density.

Map Random is a single-purpose specialisation of the general Map node (where the same behaviour is reached via the Randomize mode). Use Map Random when the chain step is unambiguously a random pass; use Map when you want a single node that flexes between modes.

Parameters

Parameter	Description
Name	Identifier for the random pass.

Target

Parameter	Description
Target	The target of the random output (the socket or attribute this map writes into).

Blending

Parameter	Description
Blend Mode	How the random result combines with the incoming value (replace, add, multiply, etc.).

Map

Parameter	Description
Driver Name	The attribute that seeds the random values. The same driver value always produces the same random result.
Driver Range	Range of driver values used for seeding.
Driver Level	Level on which the driver is evaluated.

Remap

Parameter	Description
Passenger Range	Output range the random values are mapped into.

Ramp

Parameter	Description
Position / Value / Interpolation	Ramp controls for shaping the random distribution.

Advanced

Parameter	Description
parm	Advanced parameter hook.
Code	VEX snippet for custom logic.

Notes

The driver attribute decides what counts as "the same internode": pick id for stable per-internode jitter; pick branch_id for stable per-branch jitter that shares within a branch but differs between branches.

See also: Mapping · Variation · Map · Map Attribute · Map Constant · Map If · Map Blend

Map If

Conditional mapping node. Applies a map chain only if a condition is met.

Mapping Template

Authoring node for defining mappable parameters on a target HDA. Used when building custom modules or wrappers that need their own promotable parameter surface.