Halo 4 Grifball anfd Forge World

I’ve heard that there will be Grifball in Halo 4 but I can’t find it anywhere or has it just not been released yet? And in forge how do you get a blank canvas like forge world in halo reach?

two things, its only in custom games for now suposed to be putting grifball in playlist soon i’m trying to find out when, secondly erosion, ravine, and impact are the total forge maps, go in to tools, delete palette, very bottom, delete everything will make a blank canvas