Too many texture interpolators would be used- Shader with rotation - c++

Question

I use a shader that has a rotation over time option, and it worked great for years,
But after updating Unity (2017.2 to 2018.2) I get this error- "Shader error in 'Custom/NewSurfaceShader': Too many texture interpolators would be used for ForwardBase pass (11 out of max 10) "
and the material using this shader became white.
I don't know what to do, I looked online but everyone has a different problem
Here is my code:
Shader "Custom/NewSurfaceShader" {
Properties{
//Tint
_Color("Color", Color) = (1,1,1,1)
//Textures and Alphas
_TexOne("Texture One (RGB)", 2D) = "white" {}
_TexTwo("Texture Two (RGB)", 2D) = "white" {}
_AlphaTexOne("Alpha One (A)", 2D) = "white" {}
_AlphaTexTwo("Alpha Two(A)", 2D) = "white" {}
_AlphaTexThree("Alpha Two(A)", 2D) = "white" {}
_Brightness("Brightness", Range(0,5)) = 1
_AlphaWeakness("Alpha Weakness", Range(0,10)) = 1
_ScrollSpeed1X("Scroll Speed Texture One X", Range(-10,10)) = 0
_ScrollSpeed1Y("Scroll Speed Texture One Y", Range(-10,10)) = 0
_ScrollSpeed2X("Scroll Speed Texture Two X", Range(-10,10)) = 0
_ScrollSpeed2Y("Scroll Speed Texture Two Y", Range(-10,10)) = 0
_ScrollSpeedAlpha1X("Scroll Speed Alpha One X", Range(-10,10)) = 0
_ScrollSpeedAlpha1Y("Scroll Speed Alpha One Y", Range(-10,10)) = 0
_ScrollSpeedAlpha2X("Scroll Speed Alpha Two X", Range(-10,10)) = 0
_ScrollSpeedAlpha2Y("Scroll Speed Alpha Two Y", Range(-10,10)) = 0
_RotationSpeed1("Rotation Speed Texture 1", Float) = 0.0
_RotationCenter1("Rotation Center Texture 1", Range(0,1)) = 0.5
_RotationSpeed2("Rotation Speed Texture 2", Float) = 0.0
_RotationCenter2("Rotation Center Texture 2", Range(0,1)) = 0.5
_Speed("Wave Speed", Range(-80, 80)) = 5
_Freq("Frequency", Range(0, 5)) = 2
_Amp("Amplitude", Range(-1, 1)) = 1
}
SubShader{
//Default Queues - Background, Geometry, AlphaTest, Transparent, and Overlay
Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
LOD 200
CGPROGRAM #pragma surface surf Lambert alpha:fade vertex:vert
//sampler2D _Color;
sampler2D _TexOne;
sampler2D _TexTwo;
sampler2D _AlphaTexOne;
sampler2D _AlphaTexTwo;
sampler2D _AlphaTexThree;
fixed4 _Color;
float _ScrollSpeed1X;
float _ScrollSpeed1Y;
float _ScrollSpeed2X;
float _ScrollSpeed2Y;
float _ScrollSpeedAlpha1X;
float _ScrollSpeedAlpha1Y;
float _ScrollSpeedAlpha2X;
float _ScrollSpeedAlpha2Y;
float _RotationSpeed1;
float _RotationCenter1;
float _RotationSpeed2;
float _RotationCenter2;
float _Brightness;
float _AlphaWeakness;
float _RotationSpeed;
float _Speed;
float _Freq;
float _Amp;
float _OffsetVal;
struct Input {
float2 uv_TexOne;
float2 uv_TexTwo;
float2 uv_AlphaTexOne;
float2 uv_AlphaTexTwo;
float2 uv_AlphaTexThree;
};
void vert(inout appdata_full v) {
float time = _Time * _Speed;
// float waveValueA = sin(time + v.vertex.x * _Freq) * _Amp;
// v.vertex.xyz = float3(v.vertex.x, v.vertex.y + waveValueA, v.vertex.z);
// v.normal = normalize(float3(v.normal.x + waveValueA, v.normal.y, v.normal.z));
}
// This is the only code you need to touch
void surf(Input IN, inout SurfaceOutput o) {
//Rotation
float sinX, cosX, sinY;
float2x2 rotationMatrix;
sinX = sin(_RotationSpeed1 * _Time);
cosX = cos(_RotationSpeed1 * _Time);
sinY = sin(_RotationSpeed1 * _Time);
rotationMatrix = float2x2(cosX, -sinX, sinY, cosX);
//Center the rotation point and apply rotation
IN.uv_TexOne.xy -= _RotationCenter1;
IN.uv_TexOne.xy = mul(IN.uv_TexOne.xy, rotationMatrix);
IN.uv_TexOne.xy += _RotationCenter1;
sinX = sin(_RotationSpeed2 * _Time);
cosX = cos(_RotationSpeed2 * _Time);
sinY = sin(_RotationSpeed2 * _Time);
rotationMatrix = float2x2(cosX, -sinX, sinY, cosX);
//Center the rotation point and apply rotation
IN.uv_TexTwo.xy -= _RotationCenter2;
IN.uv_TexTwo.xy = mul(IN.uv_TexTwo.xy, rotationMatrix);
IN.uv_TexTwo.xy += _RotationCenter2;
//Scrolling
IN.uv_TexOne.x -= _ScrollSpeed1X * _Time;
IN.uv_TexOne.y -= _ScrollSpeed1Y * _Time;
IN.uv_TexTwo.x -= _ScrollSpeed2X * _Time;
IN.uv_TexTwo.y -= _ScrollSpeed2Y * _Time;
IN.uv_AlphaTexOne.x -= _ScrollSpeedAlpha1X * _Time;
IN.uv_AlphaTexOne.y -= _ScrollSpeedAlpha1Y * _Time;
IN.uv_AlphaTexTwo.x -= _ScrollSpeedAlpha2X * _Time;
IN.uv_AlphaTexTwo.y -= _ScrollSpeedAlpha2Y * _Time;
//Textures
fixed4 c1 = tex2D(_TexOne, IN.uv_TexOne) * (_Color * _Brightness); // This is your color texture
fixed4 c2 = tex2D(_TexTwo, IN.uv_TexTwo) * (_Color * _Brightness); // This is your color texture
//Alphas
fixed4 a1 = tex2D(_AlphaTexOne, IN.uv_AlphaTexOne); // This is your alpha texture
fixed4 a2 = tex2D(_AlphaTexTwo, IN.uv_AlphaTexTwo); // This is your alpha texture
fixed4 a3 = tex2D(_AlphaTexThree, IN.uv_AlphaTexThree); // This is your alpha texture
//Assignment
o.Albedo = (c1.rgb * c2.rgb * 2); // Setting your color from the one texture
o.Alpha = ((a1.a * a2.a * 2) * a3.a * 2) *_AlphaWeakness; // Setting your alpha from the other texture
}
ENDCG
}
}

Answer 1

Straightforward solution: target your shader for newer platform (3.5 or higher) by adding
#pragma target 3.5 after CGPROGRAM:
CGPROGRAM #pragma surface surf Lambert alpha:fade vertex:vert
#pragma target 3.5
This is because in shader model 3.0 maximum 10 interpolators are available, i.e. your Input structure may have maximum 10 float fields. Now your structure has exactly 10 (each float2 is 2), but don't forget that the engine may have some internal interpolations that are done behind the scenes and do not come from your input data. This is the case and as a result you have 11 interpolators.
If you target older platforms, you will need to think how to optimize your shader, as there are too many field in Input structure. For example, do you really need 3 alpha channels? Do you use it all? Maybe remove uv_AlphaTexThree?