Set and use the RSUV

Learn how to set and use the Renderer Shader User Value (RSUV) through an example.

Set the value

To set the value, you have to write a script.

The following example sets a random color to all MeshRenderer of the sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary, encoded as a 24-bit integer:

        MeshRenderer[] allMeshRenderers = FindObjectsByType<MeshRenderer>(FindObjectsSortMode.InstanceID);
        foreach (MeshRenderer meshRenderer in allMeshRenderers)
        {
            // compute a random color
            Color32 c = Color.HSVToRGB(UnityEngine.Random.Range(0f, 1f), UnityEngine.Random.Range(0.6f, 1.0f), UnityEngine.Random.Range(0.6f, 1.0f));

            // set it as a LDR color in the RSUV value of the renderer
            uint cc = ((uint)c.b << 16) | ((uint)c.g << 8) | ((uint)c.r << 0);
            meshRenderer.SetShaderUserValue(cc);
        }

Use the value

Once you’ve set the value, you can use it in shaderA program that runs on the GPU. More info
See in Glossary code or in a shader graph. You can also use it with Entities Graphics.

Use the value in shader code

In shader code, you can decode the 24-bit integer as a float4 color. For example:

uint c = unity_RendererUserValue;
float4 mycolor = float4((float)((c >> 0) & 255) * (1.f / 255.f),
                        (float)((c >> 8) & 255) * (1.f / 255.f),
                        (float)((c >> 16) & 255) * (1.f / 255.f),
                        (float)1.f);

Use the value in a shader graph

In a shader graph, you need to create a custom node with an HLSL function.

For example:

1. Create a custom node by reflection from HLSL with the following function and hints:

   #include "ShaderApiReflectionSupport.hlsl"
       
   ///<funchints>
   ///    <sg:ProviderKey>DecodeRsuvColor</sg:ProviderKey>
   ///    <sg:DisplayName>Decode RSUV Color</sg:DisplayName>
   ///    <sg:SearchName>Decode Color</sg:SearchName>
   ///    <sg:SearchCategory>RSUV</sg:SearchCategory>
   ///</funchints>
   UNITY_EXPORT_REFLECTION
   float4 DecodeRsuvColor()
   {
       uint c = unity_RendererUserValue;
       float4 mycolor = float4((float)((c >> 0) & 255) * (1.f / 255.f),
                               (float)((c >> 8) & 255) * (1.f / 255.f),
                               (float)((c >> 16) & 255) * (1.f / 255.f),
                               (float)1.f);
       return mycolor;
   }
   

2. In Shader Graph, select RSUV > Decode Color to add the node reflected from the function.

3. Connect the Decode Color node’s Out port to the Fragment’s Base Color input.

Use RSUV with Entities Graphics

You can also use the RSUV feature along with Unity’s Entities Graphics package.

The following code example assigns a distinct RSUV value to all entities that include a MaterialMeshInfo component.

using Unity.Entities;
using UnityEngine;
using Unity.Rendering;
using Unity.Burst;

[MaterialProperty("unity_RendererUserValuesPropertyEntry")]
public struct RendererUserValue_BaseValue : IComponentData
{
    public uint Value;
}

[BurstCompile]
public partial struct MaterialMeshInfoDebugSystem : ISystem
{

    private bool m_done;

    public void OnCreate(ref SystemState state)
    {
        m_done = false;
    }

    public void OnUpdate(ref SystemState state)
    {
        if ( !m_done )
        {
            var entityManager = state.EntityManager;
            var mQuery = entityManager.CreateEntityQuery(ComponentType.ReadOnly<MaterialMeshInfo>());
            // subscene may not be fully loaded, so wait for some entities to be here
            if (!mQuery.IsEmpty)
            {
                using (var entities = mQuery.ToEntityArray(Unity.Collections.Allocator.Temp))
                {
                    foreach (var entity in entities)
                    {
                        Color32 c = Color.HSVToRGB(UnityEngine.Random.Range(0f, 1f), UnityEngine.Random.Range(0.6f, 1.0f), UnityEngine.Random.Range(0.6f, 1.0f));
                        uint cc = ((uint)255<<24) | ((uint)c.b << 16) | ((uint)c.g << 8) | ((uint)c.r << 0);

                        entityManager.AddComponentData(entity, new RendererUserValue_BaseValue { Value = cc });
                    }
                }
                m_done = true;
            }
        }
    }
}

Additional resources

• Introduction to RSUV
• RSUV sample