arenos-nexus/Arenos Nexus/Library/PackageCache/com.unity.shadergraph@940512a5d7e1/Documentation~/Custom-Render-Texture-Example.md

# Example Custom Render Texture with Shader Graph

This example demonstrates how to set up a Shader Graph for Custom Render Texture shaders to create a self-healing deformation effect that could be used for snow, sand, etc.

<video src="Images/CustomRenderTexture-Animation.mp4" title="A grid with various cells labeled with letter-number pairs (for example, A0, B1, G2, and so on), accompanied by arrows. Each cell is a different color. In the upper-left corner, there’s a black square with two red spots, one square and the other circular. The square remains stationary, while the circular spot traces a curve. In the upper-right corner, a black square contains the same glowing red spots, with the circular spot leaving a fading trail as it describes a curve. Above the grid, a cube corresponding to the square floats and leaves a hollow imprint behind, as if the grid were a mattress pressed by a heavy object. A red sphere traces the same curve as the circular spot, creating a furrow in the grid. The grid gradually recovers its original shape, and the furrow disappears." width="700" height="auto" autoplay="true" loop="true" controls></video>



For this effect, we need a Render Texture that contains the pixels we want to displace. This Render Texture is displayed at the top left corner of the preceding image. It was directly assigned to a camera that renders the objects in red above the UV plane.

1. Create a **Custom Render Texture** Shader Graph as follows:
   - Right-click in the Project window.
   - Select **Create** > **Shader Graph** > **Custom Render Texture** and name your shader.

2. Create a new **Custom Render Texture** as follows: 
    - Select **Create** > **Rendering** > **Custom Render Texture**. 
    - Configure the parameters to match the following settings:
      - **Dimension**: 2D
      - **Size**: 1024 x 1024
      - **Anti-aliasing**: None
      - **Enable Compatible Format**: selected
      - **Color Format**: R32_SFLOAT
      - **Depth Stencil Format**: None
      - **Mipmap**: not selected
      - **Dynamic Scaling**: not selected
      - **Random Write**: not selected
      - **Wrap Mode**: Clamp
      - **Filter Mode**: Bilinear
      - **Aniso Level**: 0
      - **Material**: SnowHeightmapUpdate
    **Note**: The material in the **Material** field was created.
      - **Shader Pass**: <Unnamed Pass 0>
      - **Initialization Mode**: OnDemand
      - **Source**: Texture and Color
      - **Color**: select a color
      - **Texture**: None (Texture)
      - **Update Mode**: Realtime
      - **Period**: 0
      - **Double Buffered**: selected
      - **Wrap Update Zones**: not selected
      - **Update Zone Space**: Normalized
      - **Update Zones**: list empty

![The Custom Render Texture inspector as it looks with the preceding settings.](images/CustomRenderTextureInspector.png)

The following Shader Graph reads the output of the Camera Render Texture, as well as the Self texture, then adds them and lerps the result so that it tends towards 0 over time. 

![The graph that is described in the preceding text.](images/CustomRenderTextureShaderGraph.png)

3. Finally you need to assign the **Custom Render Texture** to a material that can deform the geometry (tessellation or pixel displacement).

## New ShaderGraph Nodes for Custom Render Textures

Three new ShaderGraph nodes have been introduced to facilitate working with Custom Render Textures:

1. [Custom Render Texture Self](Custom-Texture-Self.md)
   - Outputs the double-buffered texture from the previous update.
   - It provides three outputs for different types of textures: 2D, 3D, and Cube textures.

2. [Custom Render Texture Size](Custom-Texture-Size.md)
   - Outputs the width, height, and volume depth of the current Custom Render Texture.
   - Use this node to determine the size of the texture being worked with.

3. [Custom Render Texture Slice](Custom-Texture-Slice.md)
   - Outputs the current slice for 2D Texture Arrays or the Cubemap face index being updated.

## Known Limitations

When working with Custom Render Texture shaders, be aware of the following limitations:

* Rendering Order
   - The Custom Render Texture update loop runs before any rendering operations. This means:
      - You cannot access any render pipeline-specific information in the shader, such as depth, normal, or scene color.
      - Despite this, you can rely on the content of the Custom Render Texture being ready for use in the scene when the camera renders.

## Additional resources
- [Custom Render Textures](https://docs.unity3d.com/Manual/class-CustomRenderTexture.html)
- [Custom Render Texture Nodes](Custom-Render-Texture-Nodes.md)