Why Bent Normal map must generate in T-Pose?

Could anyone give an explanation about this? Why can’t use A-Pose?

To minimize self occlusion?

So you not sure about this?lol

The document said that when you generate a bent normal map must make sure to use a T-pose, but what’s interesting is that they use a A-pose character to show this.

Bent normal map is great, I want to use it in my upcoming project. But the need of T-pose makes me confused because I worked at A-pose for a long time.So I want some technical explanations to see that if I could still work with A-pose. If self occlusion is the only reason, then I’m glad to use it with A-pose.

Don’t know for sure - sounds like bent normal is created by averaging AO information so keeping arms in T-Pose might limit shadowing contribution to torso more than A-Pose?

Might not be too big a deal to go with APose though