For energy conservation with Diffuse and SSS, you must have Diffuse + SSS <= 1
With Specular, it depends on whether or not Fresnel is enabled:
- If Fresnel is off, then you must have SSS + specular + diffuse <= 1
- If Fresnel is on, then you must only have diffuse + SSS <= 1. The shader will mix specular with diffuse and SSS in a way that’s energy conserving.
Ok, that’s the simple case (without diffuse backlighting and refraction). Now let’s add diffuse backlighting and refraction:
For energy conservation with Diffuse and SSS, you must have Diffuse + SSS + backlighting <= 1
With Specular, it depends on whether or not Fresnel is enabled:
- If Fresnel is off, then you must have specular + (SSS + diffuse + backlighting) <= 1
- If Fresnel is on, then you must only have diffuse + SSS + backlighting<= 1. The specular and refraction weights can be anywhere between 0 and 1, and the shader will mix everything in a way that’s energy conserving.