# Introduction to Custom Render Textures

> Learn about rendering a Render Texture via a shader, for example to create complex simulations like caustics, rain effects, and liquid splatters.

**Custom Render Textures** are a special type of texture that allow you to update a texture with a shader. They are an extension to [Render Textures](/engine/6000.0/manual/materials-and-shaders/textures/textures-reference/class-render-texture.md). You can use Custom Render Textures to create complex simulations like caustics, ripple simulation for rain effects, and liquid splatters.

The Custom Render Textures feature provides a scripting and Shader framework to help with complicated configuration like varying update frequency, partial or multi-pass updates.

To use this framework you need to assign a Material to the Custom Render Texture asset. Custom Render Textures require a compatible Material. For more information, see [Writing a shader for a Custom Render Texture](/engine/6000.0/manual/materials-and-shaders/textures/render-texture/class-custom-render-texture/write-shader.md).

## Render Pipeline Compatibility

The following table describes the compatibility between the **Custom Render Textures** feature and each render pipeline:

| Feature                | Universal Render Pipeline (URP) | High Definition Render Pipeline (HDRP) | Custom Scriptable Render Pipeline (SRP) | Built-in Render Pipeline |
| ---------------------- | ------------------------------- | -------------------------------------- | --------------------------------------- | ------------------------ |
| Custom Render Textures | Yes (1)                         | Yes (1)                                | Yes (1)                                 | Yes (1)                  |

**Note:**

1. To create Materials that update and initialize **Custom Render Textures** in [Shader Graph](https://docs.unity3d.com/Packages/com.unity.shadergraph@latest), selecting **Custom Render Texture** as the target of the shader graph.