Hello everyone, this is my first post on this forum! Well, I’m currently working on a First Person Shooter Sci-Fi game for mobile, both iOS and Android, but well more details on that soon in the Work in Progress Section…
My game will have open environments, at first i wanted to use Unity’s terrain but it’s not suitable for my game so i decided to find a SplatMap shader to use on the blender-made levels I’ll create and well… i did find one, when i test it on my iPhone 6 it seems to look just fine, HOWEVER, in my iPhone 4S it just doesn’t work… when the graphics settings are “Fastest”, “Fast” or “Simple” the geometry is invisible and when i use “Good” everything looks pink, I’m still not sure about the other iPhone versions or Android devices but this is my current problem (I’ll, however use simulators to see the outcome in other devices), any help would be much appreciated 
Here’s the code, hope you can help me out with this, so far this has been my only major issue:
Shader "747823/Splatmapped UV"
{
Properties
{
_Color ("Main Color", Color) = (0.8, 0.8, 0.8, 0)
_Spec ("Specular Power", Float ) = 0.2
_Shininess ("Glossiness", Float ) = 0.15
_BlendSoft ("Texture Blend Softness", Range(0, 1)) = 0.1
_Tex_Color ("Color map (RGB)", 2D) = "white" {}
_Tex_Splat ("Splat map (RGBA)", 2D) = "white" {}
_Tex_DiffuseR ("Splat Diffuse R (RGB), Height (A)", 2D) = "white" {}
_Tex_NormalR ("Splat Normal R", 2D) = "bump" {}
_Tex_DiffuseG ("Splat Diffuse G (RGB), Height (A)", 2D) = "white" {}
_Tex_NormalG ("Splat Normal G", 2D) = "bump" {}
_Tex_DiffuseB ("Splat Diffuse B (RGB), Height (A)", 2D) = "white" {}
_Tex_NormalB ("Splat Normal B", 2D) = "bump" {}
_Tex_DiffuseA ("Splat Diffuse A (RGB), Height (A)", 2D) = "white" {}
_Tex_NormalA ("Splat Normal A", 2D) = "bump" {}
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 300
CGPROGRAM
#pragma surface surf BlinnPhongSpecMap addshadow
#pragma target 3.0
sampler2D _Tex_Splat;
sampler2D _Tex_Color;
sampler2D _Tex_DiffuseR;
sampler2D _Tex_DiffuseG;
sampler2D _Tex_DiffuseB;
sampler2D _Tex_DiffuseA;
sampler2D _Tex_NormalR;
sampler2D _Tex_NormalG;
sampler2D _Tex_NormalB;
sampler2D _Tex_NormalA;
fixed4 _Color;
half _Spec;
half _Shininess;
half _DetailTileX;
half _DetailTileY;
half _BlendSoft;
static const float _PI = 3.14159265359f;
struct Input
{
float2 uv_Tex_Splat;
float2 uv_Tex_Color;
float2 uv_Tex_DiffuseR;
float2 uv_Tex_DiffuseG;
float2 uv_Tex_DiffuseB;
float2 uv_Tex_DiffuseA;
// float2 uv_BumpMap;
};
struct SurfaceOut
{
fixed3 Albedo;
fixed3 Normal;
fixed3 Emission;
half Specular;
fixed3 Gloss;
fixed Alpha;
};
//compares input against compares. returns 1 if input is greater than ALL compares, else 0
float cutoff( float input, float compare1, float compare2, float compare3 )
{
return ( input > compare1 && input > compare2 && input > compare3 ) ? 1 : 0;
}
float3 blend_overlay( float3 base, float3 blend )
{
return lerp((base*blend*2),(1.0-(2.0*(1.0-base)*(1.0-blend))),round(base));
}
void surf (Input IN, inout SurfaceOut o)
{
//o.Albedo = 0;
float3 c = {0, 0, 0};
//Diffuse
float4 splat = tex2D( _Tex_Splat, IN.uv_Tex_Splat );
float4 colormap = tex2D( _Tex_Color, IN.uv_Tex_Color );
float4 dr = tex2D( _Tex_DiffuseR, IN.uv_Tex_DiffuseR );
float4 dg = tex2D( _Tex_DiffuseG, IN.uv_Tex_DiffuseG );
float4 db = tex2D( _Tex_DiffuseB, IN.uv_Tex_DiffuseB );
float4 da = tex2D( _Tex_DiffuseA, IN.uv_Tex_DiffuseA );
dr.a *= splat.r;
dg.a *= splat.g;
db.a *= splat.b;
da.a *= splat.a;
//Combine all alphas to equal 1
float sum = dr.a + dg.a + db.a + da.a;
if ( sum > 0 )
{
dr.a /= sum;
dg.a /= sum;
db.a /= sum;
da.a /= sum;
}
else
{
dr.a = 1;
}
//Cutoff each alpha, comparing against each other
float dr_cutoff = cutoff( dr.a, dg.a, db.a, da.a );
float dg_cutoff = cutoff( dg.a, dr.a, db.a, da.a );
float db_cutoff = cutoff( db.a, dr.a, dg.a, da.a );
float da_cutoff = cutoff( da.a, dr.a, dg.a, db.a );
//Lerp between the smooth alpha and cutoff alpha by the softness value
//Amount to lerp should increase nonlinearly as the difference between the cutoff and smooth increases
//That way we "round the corners" as we lerp.
dr.a = lerp( dr_cutoff, dr.a, saturate( _BlendSoft ) );
dg.a = lerp( dg_cutoff, dg.a, saturate( _BlendSoft ) );
db.a = lerp( db_cutoff, db.a, saturate( _BlendSoft ) );
da.a = lerp( da_cutoff, da.a, saturate( _BlendSoft ) );
c = saturate( (dr.rgb*dr.a + dg.rgb*dg.a + db.rgb*db.a + da.rgb*da.a) * _Color );
c = blend_overlay( c.rgb, colormap.rgb );
o.Albedo = c;
//--------------------------------------------
//Specular
o.Gloss = _Spec;
o.Specular = _Shininess;
//--------------------------------------------
//Normal
float3 nr = UnpackNormal( tex2D( _Tex_NormalR, IN.uv_Tex_DiffuseR ) );
float3 ng = UnpackNormal( tex2D( _Tex_NormalG, IN.uv_Tex_DiffuseG ) );
float3 nb = UnpackNormal( tex2D( _Tex_NormalB, IN.uv_Tex_DiffuseB ) );
float3 na = UnpackNormal( tex2D( _Tex_NormalA, IN.uv_Tex_DiffuseA ) );
o.Normal = clamp( (nr.rgb*dr.a + ng.rgb*dg.a + nb.rgb*db.a + na.rgb*da.a), -1, 1 );
}
inline fixed4 LightingBlinnPhongSpecMap (SurfaceOut s, fixed3 lightDir, half3 viewDir, fixed atten)
{
half3 h = normalize (lightDir + viewDir);
fixed diff = max (0, dot (s.Normal, lightDir));
float nh = max (0, dot (s.Normal, h));
float spec = pow (nh, s.Specular*128.0);
fixed4 c;
c.rgb = (s.Albedo * _LightColor0.rgb * diff + _LightColor0.rgb * spec * s.Gloss) * (atten * 2);
c.a = s.Alpha + _LightColor0.a * (0.2989f * s.Gloss.r + 0.5870f * s.Gloss.g + 0.1140f * s.Gloss.b) * spec * atten;
return c;
}
ENDCG
}
}
This is how the splatmap shader looks like in the iPhone 6:
This is how it looks like in the iPhone 4s: