Getting Started with Solaris in Arnold for Houdini - Arnold for Houdini

Arnold for Houdini (HtoA) is a powerful rendering plugin that integrates the Arnold renderer with Houdini. Solaris is Houdini's USD-based layout and lookdev context that allows for complex scene management and rendering workflows. Getting started with Solaris in Arnold for Houdini involves setting up your environment, understanding the basic workflow, and leveraging the strengths of both Arnold and Solaris.

1. Installation and Setup

• Install Arnold for Houdini: Ensure that you have Arnold for Houdini installed. You can download it from the Autodesk website and follow the installation instructions for your operating system.
• Configure Environment Variables: Set up the necessary environment variables to point Houdini to the Arnold installation. This usually involves setting HOUDINI_PATH to include the Arnold plugin path.

2. Understanding Solaris

• USD (Universal Scene Description): Solaris leverages USD, a framework developed by Pixar for complex scene description. USD allows for efficient scene management, collaboration, and interchange between different applications.
• LOPs (Lighting Operators): In Solaris, you use LOPs to create, modify, and manage USD stages. LOPs provide a node-based workflow similar to Houdini's standard context but tailored for USD-based workflows.

3. Basic Workflow in Solaris with Arnold

• Creating a New LOP Network: Start by creating a LOP network in Houdini. This is done by adding a Solaris (stage) context, which can be found in the Tab menu.
• Importing Geometry: Use the SOP Import node to bring geometry from the SOP context into the LOP network. This node converts Houdini geometry into USD format.
• Assigning Materials: Materials in Solaris are assigned using the Material Library and Assign Material nodes. Arnold shaders can be used within these nodes to define the look of your assets.
• Setting up Lights: Use Arnold-specific light nodes available in Solaris to add lighting to your scene. These lights are fully compatible with the Arnold renderer.
• Rendering: Use the Render Settings node to define Arnold render settings. Finally, use the USD Render or Render to Disk nodes to render the scene with Arnold.