iOS shader scale issue

Hey guys,
I’m using this shader as material for some characters in a game I’m working on. It works great but there is an issue when I deploy the game to iOS, it seems it loses the objects scale information in the matcap lookup and gets a bit screwed up… it’s working perfectly on the editor. If I multiply the matcap lookup coords (vn * 0.5 + 0.5) for the objects scale the result is correct in iOS.
I’ve searched in the forums but I can’t find other people with the same problem. Has any one run into this? Could this be an issue with the iOS rendering code or am I just doing something stupid?

Shader “MatCap”
{

Properties
{
_MainTex (“Diffuse (RGB)”, 2D) = “white” {}
_BumpMap (“Bumpmap (RGB)”, 2D) = “bump” {}
_MatCap (“MatCap (RGB)”, 2D) = “white” {}
}

Subshader
{
Tags { “RenderType”=“Opaque” }
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include “UnityCG.cginc”

    uniform float4 		_Color;
        uniform sampler2D 	_BumpMap;
        uniform sampler2D 	_MatCap;
        uniform sampler2D	_MainTex;
        uniform float4 		_MainTex_ST;
        
        struct v2f 
        { 
            float4  pos   : POSITION;
            float2  uv 	  : TEXCOORD0;
            float3  TtoV0 : TEXCOORD1;
            float3  TtoV1 : TEXCOORD2;
        };
       
        v2f vert (appdata_tan v)
        {
            v2f o;
            o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
            o.uv = TRANSFORM_TEX(v.texcoord,_MainTex);
            
            TANGENT_SPACE_ROTATION;                    
            o.TtoV0 = mul(rotation, UNITY_MATRIX_IT_MV[0].xyz);
            o.TtoV1 = mul(rotation, UNITY_MATRIX_IT_MV[1].xyz);
            
            return o;
        }
        
        float4 frag (v2f i) : COLOR
        {
	float3 normal = tex2D(_BumpMap, i.uv).xyz * 2.0 - 1.0;
            normal = normalize(normal);
            
            half2 vn;
            vn.x = dot(i.TtoV0, normal);
            vn.y = dot(i.TtoV1, normal);
            
            float4 color = tex2D(_MainTex, i.uv) * tex2D(_MatCap, vn * 0.5 + 0.5) * 1.5;
            color.a = 1;
            
            return color;
        }
    ENDCG
}

}
}

Could it be related to this issue?

For anyone still looking for a solution to this issue, Unity doesn’t allow dynamic scaling unless the Read/Write Mesh flag is turned on in the mesh’s import settings. Attempting to scale at runtime with the flag off will cause strange behavior, like the mesh turning inside-out. See the “Read/Write Enabled” section of this doc page for more info: