What is GI vs. AA balance? C4D
The number of GI samples per each anti-aliasing sample. Higher values will make global illumination and light noise clean up faster, while lower values will make the antialiasing, motion blur, and depth of field noise clean up faster. Setting this value under 2 or above 64 is not recommended.
You can find GI vs. AA balance parameter in Render Settings > Corona > Performance Settings > Sampling balance.
It specifies the number of GI samples per each antialiasing sample. One antialiasing sample is cast for each pixel during one pass.
The total amount of samples is dependent on the Light samples multiplier and GI vs. AA balance values. If the Light samples multiplier is set to 1 and GI vs. AA balance is set to 16, this means that 16 GI samples and 16 direct light samples will be used for each pixel per pass. If the Light samples multiplier is set to 2 and GI vs. AA balance is set to 16, this means that 16 GI samples and 32 direct light samples will be used for each pixel per pass. In some situations, it may pay off to reduce one of these values and increase the second one, or even to reduce both. Typically, there is no need to increase GI vs. AA balance above 64 and Light samples multiplier above 4.
The default value should work well in most cases, but sometimes it should be increased if there is more noise in indirect light areas, or decreased if there is strong DoF (3ds Max | C4D) or motion blur (3ds Max | C4D) in the scene.
GI vs. AA = 16
LSM = 1
The same number of samples (16) is used for both GI and direct light samples. Noise level is similar in areas affected by GI and direct light.
GI vs. AA = 16
LSM = 4
16 samples are used for GI, and 16x4=64 samples are used for direct light. There is visibly less noise in direct light pass than in GI pass.
GI vs. AA = 64
LSM = 0,25
64 samples are used for GI, and 64x0,25=16 samples are used for direct light. There is visibly more noise in direct light pass than in GI pass.