Changing point light falloff for standard shader?

Hello. I really hate the way the light falloff / attenuation looks for point and spot lights, particularly in linear lighting mode. I'd light to make a falloff curve that's more realistic.

I've been looking through the CGIncludes folder, trying to find the right part of the source code to edit. The closest thing I've been able to find is in UnityDeferredLibrary.cginc, there's a bit that's like

float3 tolight = wpos - _LightPos.xyz;
half3 lightDir = -normalize (tolight);

float att = dot(tolight, tolight) * _LightPos.w;
float atten = tex2D (_LightTextureB0, att.rr).UNITY_ATTEN_CHANNEL;

Which to me looks like the right thing. But changing this makes no difference at all. Is this part of the code even used by the standard shader? Or is this part of the legacy shaders or something?

The other part I've found that looks interesting is the BRDF1_Unity_PBS function in UnityStandardBRDF.cginc. Messing around with this function seems to effect the material preview sphere, but not the actual scene view etc. Also, unfortunately I can't see anything about distance in there.

Can anyone point me in the right direction? @Aras maybe?

 

Maybe this is what you are looking for?

http://forum.unity3d.com/threads/ea...ation-with-deferred-path.254337/#post-1681835

 

Looks like there's a lot of good information there, thanks! The bit about needing to restart the editor sounds like something I was missing in particular.

I'll try it out next time I'm at home.

 

Well that didn't work :\ I copied Internal-DeferredShading.shader and UnityDeferredLibrary.cginc into Assets\Resources as suggested by this page http://docs.unity3d.com/Manual/RenderTech-DeferredShading.html

They definitely get built, if I mess up the code it gives me errors, but they make absolutely no difference to what I see in the scene view, game view, or final build.

I've restarted the editor many times too.

Am I doing something wrong or is this kinda broken in 5.0 at the moment? Has anyone managed to get this to work at all in 5.0?

 

Did you tried the texture lookup version? I don't know if unity 5 changed anything, but considering the code you provided earlier I'm guessing it's still using a texture to find out the falloff so changing the code to support a custom texture should indeed work.

 

Unfortunately my problem is more fundamental than that. Unity isn't even using the code in my Assets/Resources folder. It's compiling it, but then it clearly uses its built in stuff anyway.

 

I had that problem before, actually had to override the standard shader to use different includes pointing to mine because for some reason i never discovered it wasn't picking up the ones in the resources folder that were supposed to be overriding the default ones. It's a pain actually, i had to change a bunch of includes all over the place, but after that it worked.

 

Hmm. So putting the files in the Resources folder is meant to work but doesn't. So it's an actual bug?

It would be really nice if a member of the Unity team could chime in here. @Aras @KEngelstoft ?

 

Thank you @UnityGuillaume That actually worked!