Making character in Blender with Rigify. Imported as usual... In animations i noticed on my tail is bending so bad... i assuming this is problem in weight paint. I think in blender and unreal engine they are applying weight paint differently, in UE weight paint applying little harder... probably. And i noticed, my tail is going through neck a little bit, in blender perfectly fine. What is happening?
It could be a normalization problem: in Blender if a vertex has a sum of weights different than 1.0, an automatic normalization gets applied, while probably UE uses another algorithm. Try to normalize your weights before exporting (in weight paint mode, weights menu, "Normalize All", then enable the "Auto normalize" option during weights adjustments).