As of version 18.2.1 of the Radeon drivers, this problem has been fixed by AMD. The easier, better and more reliable solution now is to update your drivers to 18.2.1 or later. You can find more info and download the driver here: https://www.amd.com/en/support/kb/release-notes/rn-rad-win-18-2-1

If you have previously followed this guide, please folllow the 'how to revert' instructions to have the game run using the proper drivers again.








Below is the original guide, kept in case anyone still needs it.

Your game will look like this on Radeon driver 17.8.1 or later.

• Do not apply this patch unless you are encountering issues. This patch may instead break the game if you are not on one of the Radeon driver versions having this problem.
  
• If there has been a game update since this patch it may not be safe to apply this patch as it could break the game.

• http://www.stack.nl/~vdz/patches/ReBirth2OnRadeon.rar
  
• Mirror: http://vdzserver.org/misc/ReBirth2OnRadeon.rar
  
• Mirror 2: https://mega dot nz/#!9qAUVC6a!n9DSnqBOFxIUZvwio32ymN2WxzWv6_02XhelSUScZ64 (replace 'dot' with '.', needed to avoid Steam's automatic link filter)

• Extract the archive contents to your game folder. By default, this is:
  C:\Program Files (x86)\Steam\SteamApps\common\Neptunia Rebirth2
  One file (NeptuniaReBirth2.exe) will be overwritten.
  
• That's all. The game will now use the Radeon 17.7.2 driver file, fixing the glitches.

She's no Neptune, but Nepgear also looks pretty cute without corrupted textures.

• Delete 'atioglxx.dll'
  
• Delete 'atiglpxx.dll'
  
• Delete 'NeptuniaReBirth2.exe'
  
• Delete 'NeptuniaReBirth2.exe.local'
  
• Rename 'Original_NeptuniaReBirth2.exe' to 'NeptuniaReBirth2.exe'

If the game has received an update since this patch release, you may also need to right-click the game in your Steam library, click 'Properties', 'Local Files', and click 'Verify Integrity of Game Files'.

• Starting with Radeon 17.8.1, AMD has made significant changes to its implementation of OpenGL. These changes are not compatible with the Neptunia Re;Birth games or perhaps with NVIDIA's 'Cg Toolkit' which is used by the Re;Birth games for graphics rendering. The result is corrupted textures which result in messy ("rainbow" or "LSD") graphics. These issues occur on all 3D graphics. Specifically, this occurs during area exploration, in combat, and when viewing your equipment via the menu. In the (at the moment of writing) 4.5 months and many releases since this issue was first reported, AMD has done nothing to fix it or even reassure the Neptunia fanbase this issue is being looked into. There is unfortunately no indication of this getting fixed any time soon.
  
• The bug exists in the part of the Radeon driver containing the OpenGL implementation, "atioglxx.dll".
  
• This workaround (and certain other workarounds) solves the problem by forcing the game to use the Radeon 17.7.2 version of "atioglxx.dll". This is unfortunately a hacky way of solving the problem and will inevitably break at some point in the future (when AMD breaks compatibility with the old "atioglxx.dll"), but for now it's the only solution other than downgrading your driver to 17.7.2.
  
• Unfortunately, just putting "atioglxx.dll" next to the game does not work on most systems. This is because the game does not have the DLL in its import table or call LoadLibrary on "atioglxx.dll"; instead, the Cg Toolkit asks Windows for an OpenGL interface, Windows loads the main Radeon driver (using its absolute path on most systems, not checking for an alternative DLL next to the game) which in turn loads the Radeon OpenGL driver library using an absolute path which normally skips the local DLLs next to the game. This patch uses Windows's DLL Redirection feature to force it to ignore the absolute path it's given and load the local DLL anyways. This is done by having a .local file next to the game executable and removing the executable's manifest resource (I did this via CFF Explorer).
  See https://msdn.microsoft.com/en-us/library/windows/desktop/ms682600(v=vs.85).aspx for details on DLL Redirection.
  
• "atiglpxx.dll" is included because the old "atioglxx.dll" may not be compatible with newer "atiglpxx.dll" driver files on all systems.
  
• Original_NeptuniaReBirth2.exe is the unmodified game executable. It is not used by this patch, but provided to make it easy to revert to the original version.

• Thanks to Erebus on the Re;Birth3 Steam forum for pointing me to the option of DLL Redirection. This was the essential key to making a patch that does not affect your system and only applies to the game.
  
• Patch "made" by VDZ (I just copied atioglxx.dll, added a .local file, removed the manifest and uploaded it all).
  
• Special thanks to [HomuHomu] IJ for verifying this solution works and making a patch for SeHa.

I have also made a patch to solve this issue for the other Re;Birth games, and [HomuHomu] IJ has made a patch for SeHa:

• Re;Birth1:
  https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=1267010347
  
• Re;Birth3:
  http://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=1267750505
  
• SeHa (by [HomuHomu] IJ):
  https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=1243213830

Neptune is best girl.