360 Capture

I want to make 360 image for PC games.So I hooked UGameEngine::Tick and RenderViewFamily_RenderThread.When UGameEngine::Tick was called,I called the origin function 6 times(0 front,1 right,2 back,3 left,4 up,5 down) to add 6 graph tasks.After that I can capture 6 textures in RenderViewFamily_RenderThread.With a capture fps,the frames like that:
n n n 0 1 2 3 4 5 n n n 0 1 2 3 4 5 n n n…
But I found a problem that the captured 6 textures will mix some other color of normal texture.It seems that blending had happened between these textures,especially the 0th texture.
How can I get clear textures without any mixed color?