Install Natsura (Windows)

Before you start

This is a Windows-only, step-by-step guide for installing Natsura using Houdini’s package system – without the Natsura Launcher.

For which Houdini versions each Natsura build supports, see
Natsura & Houdini Compatibility (separate page).

You should be able to say “yes” to all of these:

• ✅ You’re on Windows 10 or 11
• ✅ You have the SideFX Houdini Launcher installed
• ✅ You have Houdini 20.5 – Python 3.11 (production build) installed from the SideFX launcher
• ✅ Houdini starts without license errors

Step 1 – Install Houdini 20.5 (Python 3.11)

1. Open the SideFX Houdini Launcher.
2. Install Houdini 20.5 – Python 3.11 (production build).

• ❌ Not Houdini 21
• ❌ Not Houdini 20.5 Python 3.10
• ❌ Not Daily / experimental builds

Step 2 – Run Houdini once

1. In the SideFX launcher, start Houdini 20.5 – Python 3.11.
2. Confirm:
   • Houdini opens.
   • No license error windows appear.
3. Close Houdini.

This creates the folder:

C:/Users/yourwindowsusername/Documents/houdini20.5/

If your name is aHamerRocks, the path should look like this:

C:/Users/aHamerRocks/Documents/houdini20.5/

Step 3 – Download and unzip Natsura

1. Go to https://natsura.com.
2. Log in / create an account.
3. Download the latest Natsura build for Windows (ZIP).
4. In File Explorer, create this folder:

C:/Users/yourwindowsusername/Documents/natsura

5. Unzip the Natsura ZIP into that folder.

You should now have:

C:/Users/yourwindowsusername/Documents/natsura/houdini20.5/
C:/Users/yourwindowsusername/Documents/natsura/houdini20.5_UI/   (optional)

Example on Windows (what it should look like):

Avoid:

• ❌ C:/Program Files/...
• ❌ Network drives
• ❌ Aggressive cloud-sync folders

Step 4 – Open the Houdini 20.5 folder

In File Explorer, go to:

C:/Users/yourwindowsusername/Documents/houdini20.5/

You’ll put the Natsura package file in here (next step).

⚠️ If this folder doesn’t exist, see Troubleshooting → “I don’t have a houdini20.5 folder”.

Step 5 – Create the packages folder

Inside:

C:/Users/yourwindowsusername/Documents/houdini20.5/

you must have a folder named packages.

If it doesn’t exist, create it:

C:/Users/yourwindowsusername/Documents/houdini20.5/packages/

Rules:

• ⚠️Name must be exactly packages.
• ⚠️ Lowercase, no spaces, no extra characters.

Step 6 – Create natsura.json

Now you tell Houdini where Natsura lives.

1. Open:

   C:/Users/yourwindowsusername/Documents/houdini20.5/packages/
   

2. Right-click → New → Text Document.
3. Name it exactly: natsura.json
   (not natsura.json.txt – enable file extensions if needed).
4. Open natsura.json in your text editor.
5. Paste this:

{
  "path": [
    "$NATSURA",
    "$NATSURA_UI"
  ],

  "load_package_once": true,
  "enable": true,
  "version": "20.5",

  "env": [
    {
      "NATSURA_ROOT": "C:/Users/yourwindowsusername/Documents/natsura"
    },
    {
      "NATSURA": "$NATSURA_ROOT/houdini20.5"
    },
    {
      "NATSURA_UI": "$NATSURA_ROOT/houdini20.5_UI"
    }
  ]
}

Screenshot example of the correct place:

1. In File Explorer, go to the Natsura folder:

   C:/Users/yourwindowsusername/Documents/natsura
   

2. Click once on the address bar at the top.
   It becomes plain text like:

   C:\Users\yourwindowsusername\Documents\natsura
   

3. Press Ctrl + C to copy it.
4. In natsura.json, replace the NATSURA_ROOT line with the correct path:

   "NATSURA_ROOT: C:\Users\yourwindowsusername\Documents\natsura"
   

5. now, you must change the slashes from \ to /

"NATSURA_ROOT": "C:/Users/yourwindowsusername/Documents/natsura"

✅ Only forward slashes /.
❌ Do not leave any backslashes \ in the JSON path.

Step 7 – Start Houdini and check Natsura

Now we do the first and only check.

1. Start Houdini 20.5 – Python 3.11.
2. Watch the startup:
   • No license errors.
   • No Python/Qt errors mentioning Natsura.
3. When Houdini is open, it should look similar to:

You’re done if:

• Title bar says Houdini 20.5.x – Py3.11.
• You see a Natsura menu / shelf.
• The Natsura Simulate node works without Python/Qt errors.

Your folders and file should look like:

The first time Natsura runs, it will ask for your Natsura license key:

1. Go to https://natsura.com.
2. Open your dashboard.
3. Paste your license key into the prompt in Houdini.

If Natsura does not appear, go to Troubleshooting.

Troubleshooting

C:/Users/yourwindowsusername/Documents/houdini20.5/

C:\Users\yourwindowsusername\Documents\natsura

"NATSURA_ROOT": "C:/Users/yourwindowsusername/Documents/natsura"