Problems with URP custom post-processing

Graphics Render Pipelines
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1

Foreword: I do not have that much experience with rendering, this is my first time exploring the topic.

So I created a Scriptable render feature using this tutorial.
I got graphics working perfectly fine, except when the new renderer feature is enabled, it just displays a black screen. I don’t really know exactly what I’m doing so I don’t really know what’s going wrong.

A few screen shots and some code:

My ScriptableRendererFeature -

using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class BlitMaterial : ScriptableRendererFeature
{
    class CustomRenderPass : ScriptableRenderPass
    {
        public RenderTargetIdentifier source;
        public Material toApply;
        RenderTargetHandle temp;

        public override void Configure(CommandBuffer cmd, RenderTextureDescriptor cameraTextureDescriptor)
        {
            temp.Init("_temp");
        }

        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
            CommandBuffer cb = CommandBufferPool.Get();

            cb.GetTemporaryRT(temp.id, renderingData.cameraData.cameraTargetDescriptor);
            Blit(cb, source, temp.Identifier(), toApply);
            Blit(cb, temp.Identifier(), source);

            context.ExecuteCommandBuffer(cb);
            cb.Release();
        }
    }

    public Material ApplicableMaterial;
    CustomRenderPass m_ScriptablePass;

    public override void Create()
    {
        m_ScriptablePass = new CustomRenderPass();
        m_ScriptablePass.renderPassEvent = RenderPassEvent.BeforeRenderingPostProcessing;
    }

    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        m_ScriptablePass.toApply = ApplicableMaterial;
        m_ScriptablePass.source = renderer.cameraColorTarget;
        renderer.EnqueuePass(m_ScriptablePass);
    }
}

The 2D Lit shader graph I’m using for my material -

7673389--958657--upload_2021-11-20_5-12-52.png
7673389--958657--upload_2021-11-20_5-12-52.png907×482 112 KB

The two frame debugger draws for each Blit -
7673389--958660--upload_2021-11-20_5-14-23.png
In this one, you can see the camera color texture has some white text inside of it
7673389--958669--upload_2021-11-20_5-15-11.png
In this one, the _MainTex property is completely black. ???
Blit in the documentation says it copies to the material’s _MainTex, but here it looks like it isn’t doing much of anything. I’m just more confused than anything.

Thanks in advance.

2

Try blitting to renderer.cameraColorTarget instead of source in your second blit there.

3

m_ScriptablePass.source is set to renderer.cameraColorTarget before the render is queued. It should be directly referencing renderer.cameraColorTarget through the source variable. In any case, I tried passing in a ScriptableRenderer instead of a RenderTargetIdentifier but it didn’t help.
m_ScriptablePass.source = renderer;
instead of
m_ScriptablePass.source = renderer.cameraColorTarget;