tex2Dbias on iOS

Unity Engine
,
1

I’m trying to use tex2Dbias in a surface shader to get “free” blurring of a texture, it doesn’t seem to be working.

sampler2D _Reflect;
half _Roughness;
void surf(...) {
    // ...
    o.Emission = tex2Dbias(_Reflect, half4(reflUv, 0.0, _Roughness);
}

Instead, I get these errors:

Shader error in 'Custom/Metallic': Program 'frag_surf', function "ddx" not supported in this profile at line 29
Shader error in 'Custom/Metallic': Program 'frag_surf', function "ddy" not supported in this profile at line 29
Shader error in 'Custom/Metallic': Program 'frag_surf', function "tex2D" not supported in this profile at line 29

Looking at the GLSL ES 2.0 specs texture2D does support a LOD bias. Is this a Cg limitation/bug or am I doing something wrong?

2

Id like to know this too.

3

I never got tex2DBian to work, I only thing it works in Open GL Specific shaders. What I did do was set the mip map bias of a texture in code and that worked. Remember, you will only see changes if MipMapping is enabled.