float3 normal = 2.0f * normalData.xyz - 1.0f;
And it says "Transform normal back into [-1,1] range".
I don't get why this transformation is needed when receiving the normals. Can someone tell me the reason behind this ?
I've tried doing that in my shader and the only visual difference I see is that it gets brighter/darker doing it with or without the * 2.0f - 1.0f part. So how do I know which one is "correct"?