Installing Arnold and its plugin in Houdini

TECH

1/23/20251 min read

Fixing Arnold for Houdini Setup Issues (HtoA) on Windows

If you're having trouble setting up Arnold in Houdini (HtoA), follow these steps to solve it.

Step 1: Download the Right Versions
  1. Go to the Arnold Download Page and log in to Autodesk.

  2. Download Arnold that matches your version of Houdini.

Step 2: Install Arnold for Houdini (HtoA)
  1. Run the Arnold installer.

  2. Find your Arnold installation folder. For example, mine is located at:

    C:\Users\YourUsername\htoa\htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310

    Make sure your folder contains the correct subfolders like:

    • arnold

    • config

    • scripts

    This will ensure you're in the right directory for HtoA.

Step 3: Configure Houdini to Use Arnold

Option 1: Edit houdini.env

  1. Go to C:\Users\YourUsername\Documents\houdini20.5\houdini.env.

  2. Add these lines, but replace YourUsername with your actual Windows username and replace the path htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310 with the actual path where Arnold for Houdini (HtoA) is installed on your system.

    For example, if your Arnold for Houdini is installed in:

    The lines should look like this:

    HOUDINI_PATH = C:/Users/YourUsername/htoa/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310;&

    PATH = $PATH;C:/Users/YourUsername/htoa/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310/bin

Option 2: Use htoa.json (Package System)

  1. Go to C:\Users\YourUsername\Documents\houdini20.5\packages.

  2. Create or edit htoa.json with the following, but replace YourUsername and the Arnold path htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310 with your actual paths:

    For example:

    {

    "env": {

    "HOUDINI_PATH": "C:/Users/YourUsername/htoa/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310;&",

    "PATH": "C:/Users/YourUsername/htoa/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310/htoa-6.3.2.2_r5cd9303_houdini-20.5.278.py310/bin;$PATH"

    }

    }

Step 4: Restart Houdini
  1. Close and reopen Houdini.

  2. Check if Arnold is available in Render Settings.

Conclusion

Follow these steps to get Arnold working in Houdini. If issues persist, double-check your installation paths and license.

For more detailed information, check the official Arnold for Houdini installation guide.

For more info, visit the Arnold Download Page.