I bought this game a long time ago, and i couldn't finish it because of the mouse acceleration that no one could help me with. Now i recently bought the game from GOG, hoping that GOG maybe fixed it or something, but it's still there. I know i can play in isometric view, but i want to be in OTS.

Can anyuone help me with this? I've tried just about everything. Surely i can't be the only one who has this extreme negative acceleration.

I have this problem as well. I don't understand at all why nobody else notices it. It makes the game barely playable.

Since the OP is fairly old and no one posted a solution, I'd highly recommend sending the GOG support team a trouble ticket. They're very helpful and usually solve tech issues fairly quickly.

I'm guessing it has something to do with you personal set-up specs, as I never had any acceleration problems nor have I come across anyone who had them.

Maybe. Other games work fine, though. The only other example where this happens is Divinity 2 Developers Cut.
I have proof, btw, that this actually happening. I used a tool called mouse movement recorder to highlight the issue.
The first is within the OS, showing that the mouse (Logitech G9x) generally works fine and the second is made after alt-tabbing out of the game which shows that the values are pretty messed up while playing the game.
I followed your advice though and made a support ticket and included the two screenshots. I really hope that they can fix it.

Woah, old post. I tried everything man. Absolutely everything i could find on the net, and nothing got rid of the negative acceleration. I've never encountered such an isolated and unfixable problem in a game i've played.

If you end up getting it fixed somehow, i'd appreciate it if you could let me know.

Well, I was able to improve it but it's not completely gone with this method. Oddly enough I get the best results with low DPI settings and a high polling rate, so I set the mouse to 1000 DPI, 1000 Hz and a mouse speed of 5 in my logitech setpoint II software. Still not great but the best I can do.

Great, blindsided by mouse acceleration again. I really need remember to double check every single game for this before purchasing. I guess The Witcher can enter my Hall of Shame for games that are unplayable due to demented mouse input, alongside Bioshock, Assassin's Creed 2 etc.

I do not recall any noticeable mouse acceleration, so perhaps this issue only affects some players? Then again, I didn't notice it in Bioshock either, so maybe I just don't notice it even if it's there.

I assume that everyone has checked the .ini files for mouse input options? I know that some games allow disabling of mouse acceleration through the .ini files.

This game's input problems go beyond just the negative acceleration. The mouse input is downright atrocious in general - sensitivity is directly tied to framerate. If I run the game at a fixed framerate of 120fps (capped), the mouse sensitivity is noticeably faster than if I run it fixed at 60fps. This is absolutely diabolical for anyone who's framerate is fluctuating (ie. if they ever drop below their frame cap or v-synced refresh rate), as their mouse sensitivity will be fluctuating with it. It's one of the hallmarks of a terribly designed engine (Skyrim's archaic Gamebryo engine mishandles input similarly, but at least all forms of acceleration are defeatable so an acceptable experience can be ensured by capping and maintaining that capped framerate at all costs).

What really boggles my mind, is that The Witcher is a PC exclusive. Usually mishandled input like this is a symptom of half-arsed console porting (as with the Bioshock and AC2 examples) but The Witcher can use no such excuse.

I've never had such problems with either Bioshock or Witcher 1--or, come to think of it, any of the ~40 games I currently have installed...I played through W1 *three times* in fact. However, I will ssy that imo the only way to play W1 is in isometric mode--tried the OTS cam and didn't like it at all, because I can see so little of the game as I play--I felt blind. Much prefer isometric in W1.

I did have mouse problems in Planescape Torment, however--which I fixed by using Aqrit's IE Drawfix patch. I don't think the problems you allude to are that common, really, so you might want to experiment inside your own configuration a bit more. It's tempting, I guess, to want to simply blame games for this kind of thing, but when you have a Hall of Shame with numerous games you play, written by different people and using differing games engines, but exhibiting the *same* problem, it probably is time to look at your configuration with x-ray specs. It could be something as simple as you needing a new mouse...

Also, important, don't forget to turn off certain mouse acceleration features through the Windows control panel. In the Mouse/Pointer Options tab, there is a box at the top called "Motion" with a slider, and a checkbox at the bottom that reads "Enhance Pointer Precision". I always run with the box unchecked and cleared which turns off this feature. When you turn it on, what it does is to vary the acceleration of the pointer with the rate at which you move the mouse--ie, the faster you move your mouse the greater the acceleration of the pointer in a linear fashion--which sounds a lot like what you are describing. It creates *uneven mouse acceleration* and so I keep it turned off. You might want to take a look, can't hurt...Good luck!

I played The Witcher in OTS, and I never had any problems either. I do wonder if the issue only affects a small portion of players.

That would be my guess...there were some early W8 problems with mouse acceleration in some older games, but they've pretty much eliminated that problem with the 8.1 update and subsequent updates--at least, I don't have any problems mouse-wise. The OTS thing is funny...because I've always wished for an isometric mode for W2...;) I think that W1 was the first game I played in which I really liked the isometric mode, mainly I think because you aren't really locked into it...scrolling in and out with the mouse wheel seemed to work well so that I could get fairly close in when I wanted to. Or so I remember, anyway...;)

I guarantee the problem is there for everyone, with the people who 'don't have it' just not being bothered by it. I've already been through this on another forum; I posted about the issue, and someone immediately responded with the "well I don't have that issue...", but before long they admitted that, on closer inspection, the negative acceleration was present. it also came out that they use an extremely high sensitivity (2cm mouse track for a 360 spin or something) so it doesn't surprise me that they were less effected by the negative acceleration under those circumstances.

Further, it came to light that the additional framerate/sensitivity issue I mentioned above is a known 'feature' of this particular engine, and is present in other games using the same engine. Like I said, some aspects of the engine seem poorly designed.

It has nothing to do with Windows 8 (I'm using 7 for the record), or any misconfiguration of mouse settings in Windows or input drivers. After years of competitive first person shooters I've a pretty good handle on all that.

As for Bioshock, there is absolutely no ambiguity when it comes to that games input issues. It has acceleration, and that is a well known fact. If you don't detect it, then it only means that you're not particularly sensitive to bad input, which I would regard as a blessing.

I sincerely hope that The Witcher's devs manage proper mouse input in the third game. That game is really beginning to pique my interest. Supergibb, have you played The Witcher 2? If so, was the mouse input clean?

The Witcher uses a modified version of Bioware's Aurora Engine, so it could be a remnant of that. The Witcher 2 has an entirely new engine and it controls very differently. So there's a good chance the input problems may be fixed, but as I'm not particularly sensitive to mouse acceleration I can't say for sure. The third game is yet another new engine, I believe, but looks closer to the second game in its style.

I know you will probably never read this, but you can play Bioshock with mouse lag. Use the wrench instead of guns, and go for all wrench perks and you will be questioning why guns were even put into the game! Also, buy lots of health packs.