In the SHOP context Tab > Arnold > Arnold Shader Network to create an arnold_vopnet1 node. Double clicking or pressing "I" enters a custom VEX builder context where Arnold shaders and nodes can be networked together.
There are 3 types of output depending on the purpose of the shader network; Material, Light and Environment. The result of the shader network must be connected to the input of the relevant output node. Multiple Outputs of different types can be contained within the same shader network. If multiple outputs of the same type exist, Arnold will use the first one translated by HtoA.
- surface: To connect the color output of a surface shader like Standard or Lambert.
- bump: Connects a bump2d or bump3d node to modify the surface normals.
- displacement: Connect a bitmap texture (image node) or procedural texture, like noise, to displace the geometry surface.
- volume: For connecting a Volume Collector shader.
- color: For attaching a shader (like a Physical Sky) to be used as the color of a light.
- light_filter #: Light Filter nodes are connected here. As each is connected another input will appear.
- atmosphere: For connecting the atmosphere nodes fog and volumetric scattering.
- background: For connecting background shaders like Sky or Physical Sky.
- visibility: Options to control the Background Visibility to specific rays.
To assign a vopnet drag it from the SHOP onto the geometry or use the Operator Chooser in the geometry Material tab.
The 'jump to operator' in the material tab will go to the Arnold shader network, rather than jumping to the shader inside. This is Houdini behavior, because you're assigning a SHOP and thus it brings you to it, not inside.
These are the available shaders and nodes.