# Write a render pipeline with render graph in SRP Core
Create a custom render pipeline using the [render graph system](render-graph-system.md) in SRP Core.
**Note:** This page is about creating a custom render pipeline. To use the render graph system in a prebuilt Unity pipeline, refer to either [Render graph system in URP](https://docs.unity3d.com/Manual/urp/render-graph.html) or [Render graph system in HDRP](https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@latest/index.html?subfolder=/manual/render-graph-introduction.html).
1. In your class that inherits `RenderPipeline`, create an instance of a [`RenderGraph`](../api/UnityEngine.Rendering.RenderGraphModule.RenderGraph.html). For example:
```c#
public class MyRenderPipeline : RenderPipeline
{
...
RenderGraph myRenderGraph;
myRenderGraph = new RenderGraph("MyRenderGraph");
}
```
**Note:** To optimize memory usage, use only one instance. You can use more than one instance of a render graph, but Unity doesn't share resources across `RenderGraph` instances.
For more information about creating a render pipeline class, refer to [Creating a custom render pipeline](srp-custom.md).
2. In your render loop, create the parameters to initialize the render graph, using the `RenderGraphParameters` API. For example:
```c#
void RenderMyCamera(ScriptableRenderContext context, Camera cameraToRender)
{
context.SetupCameraProperties(cameraToRender);
var cmd = CommandBufferPool.Get("ExampleCommandBuffer");
RenderGraphParameters rgParams = new RenderGraphParameters
{
commandBuffer = cmd,
scriptableRenderContext = context,
currentFrameIndex = Time.frameCount,
};
}
```
For more information about creating a render loop, refer to [Create a simple render loop in a custom render pipeline](srp-creating-simple-render-loop.md).
3. Initialize the render graph by calling the [`BeginRecording`](../api/UnityEngine.Rendering.RenderGraphModule.RenderGraph.html) method. For example:
```c#
myRenderGraph.BeginRecording(renderGraphParams);
```
4. Run the render passes by calling the [`EndRecordingAndExecute`](../api/UnityEngine.Rendering.RenderGraphModule.RenderGraph.html) method. For example:
```c#
myRenderGraph.BeginRecording(renderGraphParams);
// Add render passes here.
myRenderGraph.EndRecordingAndExecute();
```
For more information about adding render passes, refer to [Write a render pass using the render graph system](render-graph-write-render-pass.md)
5. Execute the rendering commands. For more information, refer to [Execute rendering commands in a custom render pipeline](srp-using-scriptable-render-context.md).
6. In the render pipeline class, call the `Cleanup()` method on the RenderGraph instance to free the resources the render graph allocated. For example:
```c#
myRenderGraph.Cleanup();
myRenderGraph = null;
```
7. After the last camera renders, call the `EndFrame` method to deallocate any resources that the render graph hasn't used since the last frame.
```c#
myRenderGraph.EndFrame();
```
## Example render pipeline template
This code template is simplified. It demonstrates the clearest workflow, rather than the most efficient runtime performance.
```c#
using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.RenderGraphModule;
public class ExampleRenderPipeline : RenderPipeline
{
private RenderGraph myRenderGraph;
public ExampleRenderPipeline(ExampleRenderPipelineAsset asset)
{
myRenderGraph = new RenderGraph("My render graph");
}
protected override void Render(ScriptableRenderContext context, List<Camera> cameras)
{
foreach (var cam in cameras)
{
if (cam.enabled)
{
RenderCamera(context, cam);
}
}
}
void RenderCamera(ScriptableRenderContext context, Camera cameraToRender)
{
context.SetupCameraProperties(cameraToRender);
var cmd = CommandBufferPool.Get("Example command buffer");
RenderGraphParameters rgParams = new RenderGraphParameters
{
commandBuffer = cmd,
scriptableRenderContext = context,
currentFrameIndex = Time.frameCount,
};
try
{
myRenderGraph.BeginRecording(rgParams);
// Add render passes here.
myRenderGraph.EndRecordingAndExecute();
}
catch (Exception e)
{
if (renderGraph.ResetGraphAndLogException(e))
throw;
}
context.ExecuteCommandBuffer(cmd);
CommandBufferPool.Release(cmd);
context.Submit();
}
}
```