bypassing linear lighting limitation for the iPAD manually

the linear color space lighting is not supported for the iPAD in Unity 3.5.
I am trying to manually bypass this limitation by having the final result for a lightmaped shader to be gamma corrected?
is it possible to tell a shader to ungamma the input textures before performing calculations and just before writing the final result to gamma correct the final pixel?

 

s.Albedo = pow(tex2D(_MainTex, IN.uv_MainTex).rgb, 2.2);

// do lighting calcs, etc...

finalColor = pow (finalColor.rgb, 1/2.2);
return finalColor;

?

 

cant wait to try it! but can you tell where exactly should i include those lines in the "lightmaped/diffuse shader"

 

Uh, not sure. Basically you want to do pow(2.2) to your diffuse texture whenever you sample it.

pow(yourDiffuseTexture, 2.2);

and then once your shader is about to return it's final result you put

pow(yourFinalResult, 1/2.2);

 

the lightmaped shader has thousans of lines if you open it, i am really having diificulty placing the lines
*btw i think i need to swap your lines, ungamma (so 1/2.2) when sampling and gamma (2.2) when write.

 

Ok, i think i found the 2 functions here:
http://unity3d.com/support/documentation/ScriptReference/Mathf.GammaToLinearSpace.html
http://unity3d.com/support/documentation/ScriptReference/Mathf.LinearToGammaSpace.html
Now its a matter of knowing where to put these lines in the complex lightmaped shader so that lightmaps are computed with the diffuse texture in linear space before adding gamma in the final result.

 

Hello stramit,
1) Regarding texture baking, I am doing this in Maya via Mental Ray and not in Unity. I have a physical light setup combining different light types such as point, spot and area lights with physical attributes attached to them such IES profiles as quadratic falloff (aiming photorealisme). But textures are linearized in Maya before baking the 32 bit . EXR lightmaps, so I am doing the same thing here.
2) Testing in process.
3) Testing in process.
4) I knowing exactly what you mean, I have been dealing with this issue for years in Maya, only RGB color textures or swatches should be gamma corrected (degamma) and not greyscale textures for bump, normal, displacement, reflection or specular maps.(even if they expresses in RGB) , so that is also checked.

I will post my results as soon as step 2 and 3 are tested.

Regarding your last question, I guess I will be using a hybrid technique for 2 reasons:
A-I definitely need my photoreal lightmaps to affect the diffuse attribute of my materials
B-I should mention that i am simulating architectural materials such as ceramic,leather,glossy wood… So I really need the specular attributes for my material to simulate all these materials.
And the only way to have specular highlights work in Unity is to have them reflect a bright source of light So I need the dynamic lights to only affect my specular attribute in the material and not the diffuse attribute because we would be lighting the diffuse attribute twice (lightmaps+dynamic lights) witch is incorrect. At the end what I want is simply to have the diffuse channel to be lit by the baked EXR lightmap and the specular channel to be lit by the Unity dynamic light (as if I checked “emit specular only” in the dynamic lights) and of course lights casting secularity will be replicated in to match the lights baked into the lightmap.

 

Just found out this now, will try if how it will work with me. Thanks.