On any render distance any world will have a shadow around it that makes blocks have black side of the texture not being looked at, or if flying blocks are black being looked at , and blocks around them are normally textured. This glitch has affected all of the beta builds of mcpe 0.12.1 and is tedious when trying to look at structures at a birds eye veiw in creative mode.
This glitch happens to my Lg g4 phone.