maximum ps_5_0 sampler register index

so seeing this error in my shadergraph using LWRP,I’m guessing I’ve hit a limit on how many textures I can use in my shader. I’m just staring to work with shaders so my understanding is next to noting but I’ve seen shader that can take 256 textures , how can I use more than 16 textures in my shadergraph,please help

 

You’re limited to 16 sampler states per shader, not 16 textures. By default each texture gets its own sampler state, which means you hit the 16 sampler limit after 16 textures. You can work around this by defining a sampler state and reusing it to sample multiple textures. I believe Shader Graph has the Sampler State Node for this. However that only gets you to 128 textures. The real solution to get past that is using a texture array, which is how those shaders that advertise 256 textures work. And those shaders really have a limit of 256 texture sets, which includes the diffuse, normal, and smoothness textures. A texture array is a special kind of texture which the shader sees as a single texture, and the 256 limit has more to do with the way the texture stores which texture layer to sample. Really you could have 65536 textures in a single shader by using 128 texture arrays with 512 layers each, but that’s overkill.

If all you need is to get a few more textures, a shared sampler state is the easier option.

 

Code (CSharp):

1. // https://github.com/przemyslawzaworski/Unity3D-CG-programming/blob/master/texture_mapping.shader
2.  
3. //Shader shows configuration of using 24 textures per shader in single pass.
4.  
5. Shader "Texture Mapping"
6. {
7.     Properties
8.     {
9.         _Texture01 ("Texture 01", 2D) = "black" {}
10.         _Texture02 ("Texture 02", 2D) = "black" {}
11.         _Texture03 ("Texture 03", 2D) = "black" {}
12.         _Texture04 ("Texture 04", 2D) = "black" {}
13.         _Texture05 ("Texture 05", 2D) = "black" {}
14.         _Texture06 ("Texture 06", 2D) = "black" {}
15.         _Texture07 ("Texture 07", 2D) = "black" {}
16.         _Texture08 ("Texture 08", 2D) = "black" {}
17.         _Texture09 ("Texture 09", 2D) = "black" {}
18.         _Texture10 ("Texture 10", 2D) = "black" {}
19.         _Texture11 ("Texture 11", 2D) = "black" {}
20.         _Texture12 ("Texture 12", 2D) = "black" {}
21.         _Texture13 ("Texture 13", 2D) = "black" {}
22.         _Texture14 ("Texture 14", 2D) = "black" {}
23.         _Texture15 ("Texture 15", 2D) = "black" {}
24.         _Texture16 ("Texture 16", 2D) = "black" {}
25.         _Texture17 ("Texture 17", 2D) = "black" {}
26.         _Texture18 ("Texture 18", 2D) = "black" {}
27.         _Texture19 ("Texture 19", 2D) = "black" {}
28.         _Texture20 ("Texture 20", 2D) = "black" {}
29.         _Texture21 ("Texture 21", 2D) = "black" {}
30.         _Texture22 ("Texture 22", 2D) = "black" {}
31.         _Texture23 ("Texture 23", 2D) = "black" {}
32.         _Texture24 ("Texture 24", 2D) = "black" {}      
33.     }
34.     Subshader
35.     {
36.         Pass
37.         {
38.             CGPROGRAM
39.             #pragma vertex vertex_shader
40.             #pragma fragment pixel_shader
41.             #pragma target 5.0
42.  
43.             Texture2D _Texture01,_Texture02,_Texture03,_Texture04,_Texture05,_Texture06,_Texture07,_Texture08;
44.             Texture2D _Texture09,_Texture10,_Texture11,_Texture12,_Texture13,_Texture14,_Texture15,_Texture16;
45.             Texture2D _Texture17,_Texture18,_Texture19,_Texture20,_Texture21,_Texture22,_Texture23,_Texture24;
46.  
47.             SamplerState sampler_linear_repeat;
48.  
49.             struct structure
50.             {
51.                 float4 vertex : SV_POSITION;
52.                 float2 uv : TEXCOORD0;
53.             };
54.  
55.             structure vertex_shader (float4 vertex:POSITION,float2 uv:TEXCOORD0)
56.             {
57.                 structure vs;
58.                 vs.vertex = UnityObjectToClipPos (vertex);
59.                 vs.uv = uv;
60.                 return vs;
61.             }
62.  
63.             float4 pixel_shader (structure ps ) : SV_TARGET
64.             {
65.                 float2 uv = ps.uv.xy;
66.                 float2 scale = uv/float2(0.25,0.1666);
67.                 if (uv.x<0.25 && uv.y<0.1666)
68.                     return  _Texture01.Sample(sampler_linear_repeat, scale);
69.                 else
70.                 if (uv.x<0.25 && uv.y<0.3333)
71.                     return  _Texture02.Sample(sampler_linear_repeat, scale);
72.                 else
73.                 if (uv.x<0.25 && uv.y<0.4999)
74.                     return  _Texture03.Sample(sampler_linear_repeat, scale);
75.                 else
76.                 if (uv.x<0.25 && uv.y<0.6666)
77.                     return  _Texture04.Sample(sampler_linear_repeat, scale);
78.                 else
79.                 if (uv.x<0.25 && uv.y<0.8333)
80.                     return  _Texture05.Sample(sampler_linear_repeat, scale);
81.                 else
82.                 if (uv.x<0.25 && uv.y<=1.0)
83.                     return  _Texture06.Sample(sampler_linear_repeat, scale);
84.                 else
85.                 if (uv.x<0.5 && uv.y<0.1666)
86.                     return  _Texture07.Sample(sampler_linear_repeat, scale);
87.                 else
88.                 if (uv.x<0.5 && uv.y<0.3333)
89.                     return  _Texture08.Sample(sampler_linear_repeat, scale);
90.                 else
91.                 if (uv.x<0.5 && uv.y<0.4999)
92.                     return  _Texture09.Sample(sampler_linear_repeat, scale);
93.                 else
94.                 if (uv.x<0.5 && uv.y<0.6666)
95.                     return  _Texture10.Sample(sampler_linear_repeat, scale);
96.                 else
97.                 if (uv.x<0.5 && uv.y<0.8333)
98.                     return  _Texture11.Sample(sampler_linear_repeat, scale);
99.                 else
100.                 if (uv.x<0.5 && uv.y<=1.0)
101.                     return  _Texture12.Sample(sampler_linear_repeat, scale);
102.                 else
103.                 if (uv.x<0.75 && uv.y<0.1666)
104.                     return  _Texture13.Sample(sampler_linear_repeat, scale);
105.                 else
106.                 if (uv.x<0.75 && uv.y<0.3333)
107.                     return  _Texture14.Sample(sampler_linear_repeat, scale);
108.                 else
109.                 if (uv.x<0.75 && uv.y<0.4999)
110.                     return  _Texture15.Sample(sampler_linear_repeat, scale);
111.                 else
112.                 if (uv.x<0.75 && uv.y<0.6666)
113.                     return  _Texture16.Sample(sampler_linear_repeat, scale);
114.                 else
115.                 if (uv.x<0.75 && uv.y<0.8333)
116.                     return  _Texture17.Sample(sampler_linear_repeat, scale);
117.                 else
118.                 if (uv.x<0.75 && uv.y<=1.0)
119.                     return  _Texture18.Sample(sampler_linear_repeat, scale);
120.                 else
121.                 if (uv.x<=1.0 && uv.y<0.1666)
122.                     return  _Texture19.Sample(sampler_linear_repeat, scale);
123.                 else
124.                 if (uv.x<=1.0 && uv.y<0.3333)
125.                     return  _Texture20.Sample(sampler_linear_repeat, scale);
126.                 else
127.                 if (uv.x<=1.0 && uv.y<0.4999)
128.                     return  _Texture21.Sample(sampler_linear_repeat, scale);
129.                 else
130.                 if (uv.x<=1.0 && uv.y<0.6666)
131.                     return  _Texture22.Sample(sampler_linear_repeat, scale);
132.                 else
133.                 if (uv.x<=1.0 && uv.y<0.8333)
134.                     return  _Texture23.Sample(sampler_linear_repeat, scale);
135.                 else
136.                 if (uv.x<=1.0 && uv.y<=1.0)
137.                     return  _Texture24.Sample(sampler_linear_repeat, scale);
138.                 else
139.                     return 1;
140.             }
141.             ENDCG
142.         }
143.     }
144. }

 

Thanks for the info, looks like I will need to use a texture array. Have you done texture arrays in shadergraph I would know where to start, so I need to create a texture array or can I just plug textures in as I go

 

Unity's editor doesn't help with creating texture arrays at all. You have to construct them entirely on your own from script, or download something from the asset store which can help. Once they've been setup, they can be plugged into a sample 2d array node.

 

Ok , thanks again for all your help

 

Is this what im looking for

https://gist.github.com/Spaxe/57de76c993a4dc8bb37275acbe597ef2

 

Hi there, I have the same problem but I am using ASE. I am doing a terrain shader and I just need a few more than 16 textures, 20 in fact. Is there an equivalent of this Sampler State Node in Amplify?

 

No idea, you should ask that in the official thread for that asset.
https://forum.unity.com/threads/bes...ditor-node-based-shader-creation-tool.430959/

 

Ive used a textureArray in Amplify, seems like this is what you need. I used over 50 textures that way in a single sampler

 

Thanks Bgolus, using the Sampler State node worked perfectly to have more than 16 textures at once in a shader. Now is it optimized? Time will tell...

 

@Horus_Sungod42 How did you use SamplerState node? Just attaching its output to sampler input ok?

 

Yes