The megatexture_d3_q4_prey_mod_v1.zip file you have requested: Mods / Graphical Tweaks / Megatexture Technology Mod - 68.59mb is not available. Perhaps try browsing all files for the game Doom III and upload any files you want to share or are missing. This is the only information we could locate:
Here is a mod that greatly increases textures in DooM. Enjoy!