I have some question but I think that only someone from Epic can answer me.
I made some animation with Matinee and I am using lot of particle emitters in the scene. No when I make movie throught Matinee I will have the same patter. All the particle would match 1:1 , frame by frame so I can render milion times and my image will looks the same. Now the fun part begins. When I slightly move my camera I have different results from the particles. For example rain drops will be different than from the camera before etc. BUT when I will render this many many times, it will be the same. It looks like camera movement has something to do with RNG of the particles. If you wonder why do I need this, well I need it for stereoscopic rendering without this I cant have 3D images. I guess that this is a deep-core problem(?). This is really strange but it is very crucial for me (and my company) to have it working properly.
Hope to hear someone about this issue.