Import/Export Operators


Arnold Operators can be imported and exported by right-clicking on the Arnold output.

Tutorials about Operators can be found here.

Example use of Operators in HtoA


In HtoA, Operators are exposed as ROP nodes. Connect an Operator chain as an input of an Arnold ROP to apply the Operator chain when rendering from that ROP.

An Import/Export Arnold operators menu is available in the Arnold ROP. This enables you to export the connected ROP network as a .ass file (left) and import it back onto a different Arnold operator (right).


Assign Material ROP

The Assign Material ROP creates an HDA that wraps the Set Parameter ROP for material assignment. This can be used to change the surface, displacement or volume shader on a selection or to override shaders in an alembic procedural for example. The Assign Material ROP does the following:

  • Points to an Arnold VOP network with the material definition.
  • Finds the OUT_material.
  • Finds the connected surface, displacement and volume shaders.
  • Provides operator expressions for surface, displacement, and volume assignments automatically.
  • Translates the shaders in the Arnold shader network.

The shader network (left) can be assigned with the Assign Material ROP using a single Set Parameter ROP (right).

Internally it uses a set_parameter node and it will fill out the set_parameter assignment fields

Final result. Scene file here.