This is a custom shader and configuration that tries to hide the partially missing geometry that the extra horizontal FOV of stereoscopic 3D can show.
Its effects are exactly proportional to the separation level that you use, so it doesn't overcompensate.

To install it, copy the ShaderFixes and ShaderFixesDM folders to merge them with your existing folders. ShaderFixesDM isn't really necessary (same for the ".bin" files in ShaderFixes) because the elements in there would be automatically generated at the first launch anyway.

Then in "d3dx.ini", at the end of the "[Include]" section, add this line:

include = ShaderFixes\custom_frustum.ini


After that, while ingame, you can press ctrl+F11 to cycle through four different modes (and then back to normal). In this order, the modes are:
- Black bars at screen depth, visible for both eyes equally.
- Black bars that only appear at the affected side of the each eye. This gives the impression of black bars being in 3D space, and they only hide what is necessary.
- Stretching of the image on the X axis to cover the extra FOV. This mode effectively makes separation feel higher.
- Stretching of the image on both the X and Y axes, to preserve the original aspect ratio. This mode effectively makes separation feel higher.


Out of those four modes, if you really need this feature, I recommend the second one.


Manual configuration options and other notes:
- The ctrl+F11 hotkey is defined in the "ShaderFixes\custom_frustum.ini" file. It's the "[KeyCustomFrustum]" block.
- In that same file, x142, y142 and z142 control the RGB color components of the black bars, between 0 and 1. 0 is black, 1 is white, and you can use decimals in between.
- Make sure that the fix you're using has the x141, y141, x142, y142, z142 and x144 constants free. They will most probably be free, given the very high number.


Credits:
- Original ini and HLSL structure done by the 3Dmigoto team. Based on the upscaling shader.
- Repurposed to a frustum culling shader by masterotaku.