Using material property block with InstancedIndirect

Hello, I'm trying to use drawmeshinstancedindirect with material property block to allot different texture to each instance. Here's my shader code.

Code (CSharp):

1. Shader "Custom/DiffTex"{
2.     Properties
3.     {
4.         _TextureIdx("Texture Idx", float) = 0.0
5.         _Textures("Textures", 2DArray) = "" {}
6.         _Color("Color (RGBA)", Color) = (1, 1, 1, 1) // add _Color property
7.  
8.     }
9.  
10.         SubShader
11.     {
12.         Tags{ "RenderType" = "Opaque" }
13.  
14.         CGPROGRAM
15.  
16. #pragma surface surf Standard fullforwardshadows
17. #pragma multi_compile_instancing
18. #pragma instancing_options procedural:setup
19. #pragma target 3.5
20. #include "UnityCG.cginc"
21.  
22.         UNITY_DECLARE_TEX2DARRAY(_Textures);
23.  
24.     struct Input
25.     {
26.         fixed2 uv_Textures;
27.     };
28. #ifdef UNITY_PROCEDURAL_INSTANCING_ENABLED
29.     StructuredBuffer<float4x4> transformBuffer;
30. #endif
31.  
32.     void setup()
33.     {
34. #ifdef UNITY_PROCEDURAL_INSTANCING_ENABLED
35.         unity_ObjectToWorld = transformBuffer[unity_InstanceID];
36. #endif
37.     }
38.     UNITY_INSTANCING_BUFFER_START(Props)
39.         UNITY_DEFINE_INSTANCED_PROP(float, _TextureIdx)
40.         UNITY_INSTANCING_BUFFER_END(Props)
41.  
42.         void surf(Input IN, inout SurfaceOutputStandard o)
43.     {
44.         fixed4 c = UNITY_SAMPLE_TEX2DARRAY(
45.             _Textures,
46.             float3(IN.uv_Textures, UNITY_ACCESS_INSTANCED_PROP(Props, _TextureIdx))
47.         );
48.         o.Albedo = c.rgb;
49.         o.Alpha = c.a;
50.     }
51.  
52.     ENDCG
53.     }
54.         FallBack "Diffuse"}
55.  

I'm copying textures using Graphics.CopyTexture to Texture2DArray and then with material property block's SetFloatArray updating texture array into the shader. But it is showing first texture to all blocks while if I used it with Gpuinstance it is working well, Can anyone tell me what I'm missing.

 

Hi. That will not work with instanced indirect.

Try to add another structured buffer and add the texture index to that

StructuredBuffer<float> indexBuffer;

then sample this buffer when you need the index

float textureIdx = indexBuffer[unity_InstanceID];

 

Hello, Thanks for replying over here. I recently started learning about compute buffers and shaders so if you could answer a few doubts of mine it will be helpful.
As you suggested I added another buffer

Code (CSharp):

1.     void setup()
2.     {
3. #ifdef UNITY_PROCEDURAL_INSTANCING_ENABLED
4.         unity_ObjectToWorld = transformBuffer[unity_InstanceID];
5.         float textureIdx = indexBuffer[unity_InstanceID];
6.  
7. #endif
8.     }

But if I'm not wrong I need to replace _TextureIdx with textureIdx in surf,like following ?

Code (CSharp):

1. UNITY_INSTANCING_BUFFER_START(Props)
2.         UNITY_DEFINE_INSTANCED_PROP(float, textureIdx)
3.         UNITY_INSTANCING_BUFFER_END(Props)
4.  
5.         void surf(Input IN, inout SurfaceOutputStandard o)
6.     {
7.         fixed4 c = UNITY_SAMPLE_TEX2DARRAY(
8.             _Textures,
9.             float3(IN.uv_Textures, UNITY_ACCESS_INSTANCED_PROP(Props, textureIdx))
10.         );
11.         o.Albedo = c.rgb;
12.         o.Alpha = c.a;
13.     }

but it is not working(still same texture to all objects) can you please tell me what I'm missing out here.

 

Also I amusing following to set up block
block.SetFloatArray("_TextureIdx", m_arrTexture);

 

No. You add your m_arrTexture to a new compute buffer.
assign that to the material or materialpropertyblock

then use this
float textureIdx = indexBuffer[unity_InstanceID];

in the surface/pixel shader where you need the index. You do not need the instanced property part.

 

Hello thanks for your reply.
Yes Im pushing data in buffer
indexBuffer.SetData(m_arrTextureArr);
instanceMaterial.SetBuffer("indexBuffer", indexBuffer);

I'm creating it on setup

Code (CSharp):

1. void setup()
2.     {
3. #ifdef UNITY_PROCEDURAL_INSTANCING_ENABLED
4.         unity_ObjectToWorld = transformBuffer[unity_InstanceID];
5.         float textureIdx = indexBuffer[unity_InstanceID];
6.  
7. #endif
8.     }

And in surface giving instance to texture2d array

Code (CSharp):

1. void surf(Input IN, inout SurfaceOutputStandard o)
2.     {
3.         fixed4 c = UNITY_SAMPLE_TEX2DARRAY(
4.             _Textures,
5.             float3(IN.uv_Textures, textureIdx)
6.         );
7.         o.Albedo = c.rgb;
8.         o.Alpha = c.a;
9.  
10.     }

But nothing is being rendered after that if possible can you tell me what Im missing

 

@Rewaken I am experiencing the same issue. Have you found the solution to this problem?

 

I think I did. But honestly, I don't remember it now. I moved to custom assetstore solution GPUI for it.