How to Set MaterialPropertyAuthoring for float[] ?

Unity Engine
,
1

I know how to set MaterialPropertyAuthoring for single type property ,just like below:

using Unity.Entities;
using Unity.Mathematics;
using Unity.Rendering;

[MaterialProperty("_Length")]
public struct CustomMaterialPropertyLength : IComponentData
{
    public float LengthValue;
}

[UnityEngine.DisallowMultipleComponent]
public class CustomMaterialPropertyLengthAuthoring : UnityEngine.MonoBehaviour
{
    [Unity.Entities.RegisterBinding(typeof(CustomMaterialPropertyLength), nameof(CustomMaterialPropertyLength.LengthValue))]
    public float Length=5;

    class CustomMaterialPropertyLengthBaker : Unity.Entities.Baker<CustomMaterialPropertyLengthAuthoring>
    {
        public override void Bake(CustomMaterialPropertyLengthAuthoring authoring)
        {
            CustomMaterialPropertyLength component = default(CustomMaterialPropertyLength);
            component.LengthValue = authoring.Length;
            var entity = GetEntity(TransformUsageFlags.Renderable);
            AddComponent(entity, component);
        }
    }
}

But, when it turns to be float[ ] , it can’t work anymore,because it is managed type;

[MaterialProperty("_LengthArray")]
public struct MaterialPropertyLengthArray : IComponentData
{
    public float[] LengthArray;
}

9064024--1253578--upload_2023-6-8_0-0-11.png
9064024--1253578--upload_2023-6-8_0-0-11.png1074×310 33.1 KB

Then, I tried to change it into NativeArray

[MaterialProperty("_LengthArray")]
public struct MaterialPropertyLengthArray : IComponentData
{
    public NativeArray<float> LengthArray;
}

[UnityEngine.DisallowMultipleComponent]
public class MaterialPropertyLengthArrayAuthoring : UnityEngine.MonoBehaviour
{
    [Unity.Entities.RegisterBinding(typeof(MaterialPropertyLengthArray), nameof(MaterialPropertyLengthArray.LengthArray))]
    public float[] LengthArray = new float[]{1,1,1,1,1,1,1,1};

    class MaterialPropertyLengthArrayBaker : Unity.Entities.Baker<MaterialPropertyLengthArrayAuthoring>
    {
        public override void Bake(MaterialPropertyLengthArrayAuthoring authoring)
        {
             MaterialPropertyLengthArray component;
             component.LengthArray = new NativeArray<float>(authoring.LengthArray,Allocator.Persistent);
             var entity = GetEntity(TransformUsageFlags.Renderable);
             AddComponent(entity, component);
        }
    }
}

But there is error like this .
9064024--1253581--upload_2023-6-8_0-1-49.png

I want to change this componentData in runtime (PerInstance) , so BlobAsset doesn’t work for this.
ISharedComponent is not for AddComponent(xxxx).

Is there anyone who knows about this?

2

ECS Material Property Overrides have to be fixed sized. For dynamic sized stuff, you need a separate graphics buffer and set that as a global shader buffer, than have normal ECS material property overrides index into it.

3

It is ok to be fixed size array,like float[8] .And I hope it works as perInstance property , not global float array.
But I don’t know how to declare it in IComponentData. Could you please give some samples?

4

Yes. Though Shader Graph won’t know how to generate it so you’ll have to make the shader yourself (or inject custom code into Shader Graph).

It just gets raw MemCpy-ed, so you could have 8 individual floats in your struct, or two float4s, or a float2x4. Totally up to you.

I don’t have any examples for fixed sized arrays yet, but I do have some real-world examples of indexing into separate buffers, which I use for skinned mesh animation rendering. Is that something you’d be interested in?

5

OK , I know it. Actually, they are totally certain fields in struct, not like float[8] in shader.There will be many propertys in shader to fit feild in struct , but it can work. It seems that there is no better solution.