Does anybody knows how to used CommandBuffers with Universal Render Pipeline

[Vadim-Andriyanov]

Recently I tried to figure out how to use CommandBuffer with universal render pipeline to draw mesh.

I created CustomForward renderer data and created CustomRenderPassFeature

Then I tried to render mesh using command buffer using following code

public class CustomRenderPassFeature : ScriptableRendererFeature
{
    class CustomRenderPass : ScriptableRenderPass
    {
        private Material m_material;
        private Mesh m_mesh;

        // This method is called before executing the render pass.
        // It can be used to configure render targets and their clear state. Also to create temporary render target textures.
        // When empty this render pass will render to the active camera render target.
        // You should never call CommandBuffer.SetRenderTarget. Instead call <c>ConfigureTarget</c> and <c>ConfigureClear</c>.
        // The render pipeline will ensure target setup and clearing happens in an performance manner.
        public override void Configure(CommandBuffer cmd, RenderTextureDescriptor cameraTextureDescriptor)
        {
            if(m_material == null)
            {
                 m_material = new Material(Shader.Find("Universal Render Pipeline/Lit"));
            }
            if(m_mesh == null)
            {
                m_mesh = Resources.Load<Mesh>("Cube");
            }
        }

        // Here you can implement the rendering logic.
        // Use <c>ScriptableRenderContext</c> to issue drawing commands or execute command buffers
        // https://docs.unity3d.com/ScriptReference/Rendering.ScriptableRenderContext.html
        // You don't have to call ScriptableRenderContext.submit, the render pipeline will call it at specific points in the pipeline.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
            CommandBuffer cmd = CommandBufferPool.Get();
            cmd.DrawMesh(m_mesh, Matrix4x4.TRS(Vector3.zero, Quaternion.identity, Vector3.one), m_material);

            context.ExecuteCommandBuffer(cmd);
            CommandBufferPool.Release(cmd);
        }

        /// Cleanup any allocated resources that were created during the execution of this render pass.
        public override void FrameCleanup(CommandBuffer cmd)
        {
        }
    }

    CustomRenderPass m_ScriptablePass;

    public override void Create()
    {
        m_ScriptablePass = new CustomRenderPass();

        // Configures where the render pass should be injected.
        m_ScriptablePass.renderPassEvent = RenderPassEvent.AfterRenderingOpaques;
    }

    // Here you can inject one or multiple render passes in the renderer.
    // This method is called when setting up the renderer once per-camera.
    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        renderer.EnqueuePass(m_ScriptablePass);
    }
}

and got following results

Does anybody know how to use command buffers with universal render pipeline?

[Vadim-Andriyanov]

Solved this by using CommandBuffer.DrawMeshInstanced instead

using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.LWRP;

public class CustomRenderPassFeature : ScriptableRendererFeature
{
    class CustomRenderPass : ScriptableRenderPass
    {

        public Mesh Mesh;
        public Material Material;

        // This method is called before executing the render pass. 
        // It can be used to configure render targets and their clear state. Also to create temporary render target textures.
        // When empty this render pass will render to the active camera render target.
        // You should never call CommandBuffer.SetRenderTarget. Instead call <c>ConfigureTarget</c> and <c>ConfigureClear</c>.
        // The render pipeline will ensure target setup and clearing happens in an performance manner.
        public override void Configure(CommandBuffer cmd, RenderTextureDescriptor cameraTextureDescriptor)
        {
           
        }

        // Here you can implement the rendering logic.
        // Use <c>ScriptableRenderContext</c> to issue drawing commands or execute command buffers
        // https://docs.unity3d.com/ScriptReference/Rendering.ScriptableRenderContext.html
        // You don't have to call ScriptableRenderContext.submit, the render pipeline will call it at specific points in the pipeline.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
            CommandBuffer cmd = CommandBufferPool.Get();
            cmd.DrawMeshInstanced(Mesh, 0, Material, 0, new[] { Matrix4x4.TRS(Vector3.zero, Quaternion.identity, Vector3.one) });

            context.ExecuteCommandBuffer(cmd);
            CommandBufferPool.Release(cmd);
        }

        /// Cleanup any allocated resources that were created during the execution of this render pass.
        public override void FrameCleanup(CommandBuffer cmd)
        {
        }
    }

    CustomRenderPass m_ScriptablePass;

    public override void Create()
    {
        Debug.Log("Create");

        m_ScriptablePass = new CustomRenderPass();
        m_ScriptablePass.Mesh = Resources.Load<Mesh>("Cube123"); 
        m_ScriptablePass.Material = Resources.Load<Material>("TestMaterial123");

        // Configures where the render pass should be injected.
        m_ScriptablePass.renderPassEvent = RenderPassEvent.BeforeRenderingOpaques;
    }
   
    // Here you can inject one or multiple render passes in the renderer.
    // This method is called when setting up the renderer once per-camera.
    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        renderer.EnqueuePass(m_ScriptablePass);
    }
}