Goku7: Do Voodoo 3 drivers still use glide.dll, glide2x.dll and glide3x.dll files, like 1 and 2 used?
First off, you'll have to forgive the fact that right now I'm not at my normal comp, (this one doesn't have a 3Dfx card), so I have to base my answers off my memory of what the file names are. Once I can get back to my computer, I can double-check the results and give any corrections.
IIRC, glide2x.dll and glide3x.dll are definitely in there, heck, even 3rd party driversets aimed at the Voodoo5 6000 still have those files.
HOWEVER, "modern" (Voodoo3 and later) 3Dfx drivers do NOT use Glide to emulate D3D or OpenGL calls, like what was apparantly done for the V1/V2 OpenGL support.
For example, in the current driver set I'm using (called the "Amigamerlin 2.9"; win9x version of course

), the OpenGL ICD is a file called "3dfxogl.dll"; and from what I can tell, it shouldn't need the assistance of the Glide2x or Glide3x dlls to function; as the file's properties (under the "version tab") give it a description as being the 3Dfx OpenGL ICD, version 1.1.
Other files, like the ones involved with Direct3D, appear to use a file called 3dfxvs.dll (or some similar name), and then I think there's two other files called "3dfxvs16.dll" and 3dfxvs32.dll", but I have a feeling I've totally misnamed those three files, so I'll have to get back to you on that. It's largely because their names are so similar to each other, my memory is running their names together or something.
I'm curious of something... Did you notice an empty string value called "DriverPath" while you were messing with the registry?
IIRC, that key was empty on mine as well.
Voodoo is most likely the _only_ card that used these driver .dll-files that could be just copied into the game folder (or system folder), and that makes me think that this 'DriverPath' string value might be there for some kind of proprietary 3dfx support. Whether it's actually working support, or even existing support, I have no idea. (But one of the early demos _supposedly_ had Glide support)
If you mean in a general sense (for all games of that time period), that may be correct when it comes to the V2/Banshee/Rush, etc. I believe it was part of the whole "3dfx-miniGL" miniport fiasco, in which you needed to dump game-specific 3Dfx dll files into a specificed place in the game's install folder, that the miniport was for, in order to run OpenGL type games, because at the time 3Dfx felt that they didn't need to spend the money on licensing a proper OpenGL ICD for their drivers, and thus used these "mini-GL" drivers to wrap the OpenGL calls to the Glide API.
Would you mind trying the following: fill that string value with a path that points to your glide.dll, wherever that might be and then try different options for driver, like 2 (or even 3 or more, although normally these just turn on software rendering).
I have no idea whether the idea is to just input a path to the directory, like (C:\windows\system\) (or wherever the glide stuff normally lives), or path with filename included, like (C:\windows\system\glide.dll), so try both.
I don't really expect it to work, but who knows, maybe it will produce results of some kind.
Sure, I'll look into it when I get the next chance to use my comp, which should be later today.