# Creating a dark rooms (or caves) in Hyperfy using Blender & Substance Painter

In this tutorial, I'll guide you through the process of creating a dark room or cave like the one I created in [my homespace](https://hyperfy.io/hiro). I use Substance Painter for texturing but Blender's built-in texture painting can achieve the same results.


## Step 1: Model Your Asset

Ensure that your 3D model's normals are facing into the room. You can use Blender's "Face Orientation" overlay to check this.


Blue is good (facing in), and red is bad (facing out). Make sure everything you want inside is blue!

## Step 2: Create a Material

Create a Principled BSDF material in Blender and apply it to your UV unwrapped model. Give the material a helpful name like "demo_cave_inside", it'll help in step 7.

## Step 3: Export to .fbx

Export your model as an .fbx file to import into Substance Painter.

## Step 4: Set Up a Substance Painter Project

Open Substance Painter and set up a new project using the following settings:


You can choose a different template if you prefer; I use the Spark AR template for its pre-configured packing settings.

## Step 5: Add a Fill Layer

Add a fill layer to your model with the following channels:


In this example, I know I'm not going to use the emissive channel in this material so I use the emissive channel to paint where I want the inside of the cave to appear. This emissive channel will be mapped to the specular input in Blender's BSDF.

Settings for the fill layer:

- Base color: rgb(0,0,0)
- Roughness: 0.8
- Emissive: rgb(0.01,0.01,0.01)

This is what the model looks like now:


## Step 6: Texture the Non-Cave Parts

Use Substance Painter to texture the non-cave parts of your model. I'm just quickly applying a wood texture so you can see the difference.


## Step 7: Export the Textures

Export your textures using the following settings:


Note: I use a packed JPEG for AO, Roughness, and Metallic (ORM) which keeps everything optimised. The emissive texture is a separate JPEG which will become specular in Blender.

## Step 8: Set Up Principled BSDF Material in Blender

Import the exported textures into Blender and set up the nodes in your Principled BSDF material like this:


To get the packed channels into the appropriate inputs, use a "Separate Color" node. Red = AO, Green = Roughness, Blue = Metallic. Ensure you connect the emissive map to the specular input. You can rename this texture to "specular" in Substance Painter's export settings which helps if you tweak SP and re-export the textures.

## Step 9: Export as .glb

Export your model as a .glb file.
**Bonus:** use https://gltf.report to optimise the model.

## Step 10: Import into Hyperfy

Import your .glb file into Hyperfy to amaze your friends with your impressive cave scene!


In more complex projects, you'll probably want to add detail to your cave walls with normal maps but this should hopefully have given you the technique to get it working.