Grimrock

If your archer has the skill that lets you shoot two arrows at the same time, and you stand one space back from a movable wall with a monster on the other side, shooting at the wall results in one of the two arrows passing through the wall and sticking in the monster.

I can supply a save game demonstrating the bug - just load it up and shoot.

Detailed way to reproduce:

Oh, cool. Nice find!

The odds are that we won't fix this for Grimrock 1 but we'll make sure this bug won't slip into Grimrock 2.

Edit: oh, actually I couldn't reproduce the bug on my computer using your save game. How's your framerate? It's possible that a low framerate could make these kinds of bugs pop up more easily.

antti wrote:Oh, cool. Nice find!

The odds are that we won't fix this for Grimrock 1 but we'll make sure this bug won't slip into Grimrock 2.

Edit: oh, actually I couldn't reproduce the bug on my computer using your save game. How's your framerate? It's possible that a low framerate could make these kinds of bugs pop up more easily.

I see. Do you consider eventually a "backport" of LoG 1 to the LoG 2 engine later after the LOG2 release, for bugfixing purposes?

badhabit wrote:

antti wrote:Oh, cool. Nice find!

The odds are that we won't fix this for Grimrock 1 but we'll make sure this bug won't slip into Grimrock 2.

Edit: oh, actually I couldn't reproduce the bug on my computer using your save game. How's your framerate? It's possible that a low framerate could make these kinds of bugs pop up more easily.

I see. Do you consider eventually a "backport" of LoG 1 to the LoG 2 engine later after the LOG2 release, for bugfixing purposes?

It's doubtful. There's already a lot of "incompatibilities" between 1 and 2 so that updating LoG1 would be cumbersome.

But if you just want a LoG2-style experience in the LoG1 dungeon, I'm sure there will be a mod or two which will replicate the original dungeon.

antti wrote:But if you just want a LoG2-style experience in the LoG1 dungeon, I'm sure there will be a mod or two which will replicate the original dungeon.

hmm...

antti wrote:Oh, cool. Nice find!

Edit: oh, actually I couldn't reproduce the bug on my computer using your save game. How's your framerate? It's possible that a low framerate could make these kinds of bugs pop up more easily.

I tested with different graphics options. With minimum quality, neither of the arrows penetrate the wall. With maximum quality and vertical sync enabled, one of the arrows penetrates the wall. With max quality and vertical sync disabled, both arrows penetrate the wall.

My framerate clearly is slow enough to affect the world updates - I had to set graphics to minimum to do the iron door puzzle with the Zo shooters - and then I did it on the first try. I had to do the same to get the achievement for doing the first level in 4 minutes - it was impossible on high graphics, I could never get faster than ~4:30, but again I did it on the first try with minimum graphics and a time of ~3:30.

My graphics card is a Nvidia GT240 on Linux. Not the best card in the world, but I prefer high quality graphics to high framerate in Grimrock, and except for this bug and the above issues I haven't noticed any effect on gameplay. And it isn't *that* slow - it seems like about 30 FPS with max graphics vs 60 FPS with minimum graphics.

ali1234 wrote:My graphics card is a Nvidia GT240 on Linux. Not the best card in the world, but I prefer high quality graphics to high framerate in Grimrock, and except for this bug and the above issues I haven't noticed any effect on gameplay. And it isn't *that* slow - it seems like about 30 FPS with max graphics vs 60 FPS with minimum graphics.

Change the line "debugInfo = false" inside grimrock.cfg to "debugInfo = true".
This will enable an FPS meter in the lower left corner of the LoG screen so you don't need to guess.

I did a little testing on my own and could reproduce this bug at the very same spot you described rather quick. The lower the framerate the more often and for more arrows it happend. At 30+ FPS 1 of 2 arrow passed thru the wall now and then. At 15 FPS (lowest my old WinXP PC with it's GF7600 GT could go) both arrows went thru the wall rather often.

I also tried this in another spot: straight south from your map marker there is an Uggardian behind a wall. Here my arrows almost never passed thru the wall even at 15 FPS. To make them pass with a better rate i had to add walking towards or away from the wall.

So there seems to be more to this bug then just low framerate and a monster behind a wall.

Dr.Disaster wrote:

ali1234 wrote: I also tried this in another spot: straight south from your map marker there is an Uggardian behind a wall. Here my arrows almost never passed thru the wall even at 15 FPS. So there seems to be more to this but then just low framerate and a monster behind a wall.

I've seen that too. Behind the wall at (2) there are three monsters: two ice lizards and a shrak torr. Shooting either ice lizard wall has the same result but shooting the shrak torr wall doesn't show the bug (or at least not as much.)

I enabled the FPS display. I get 60 FPS with low graphics, 20 FPS with max graphics and vsync enabled, and 28 FPS with max graphics and vsync disabled. The bug is worst at 28 FPS (both arrows go through).

I also found I could reproduce the bug with low graphics by using the framerate limiting option in the config file. Anything less than 30 FPS seems to trigger it.

I agree it would be nice to have this fixed. On the other hand i must admit that it is literaly "nice to have" because it does not disturb me for several reasons.

Reason 1: system performance
Right now we can say that this bug happens the more likely the lower the used systems specs are in regards of GPU. As a matter of fact i had to slow down my XP PC's 7 year old AGP GF7600 GT to the max to experience this bug. As a comparison: an Intel HD 3000 GPU about 50% more rendering power and ali1234's GT 240 is more then three times as powerfull. Still my GF7600 GT can run LoG between 35 and 55 FPS by two simple settings and still look great: the most demanding gfx stuff is set to "low" (shadows) respectivly "off" (SSAO).

Reason 2: gameplay impacts
a) Exploit
Can this be exploited to ..
- find secret doors?
>> it's possible but the throw-at-secret-doors-bug does a way better "job"
- kill monsters without any danger?
>> Possible: yes. Desireable: depends on the amount of ammo available and the amount of monster(s) behind a wall. When you run out of ammo before you get behind this wall you can get into a lot of trouble until then so it's questionable that the assassination of a few unaware monsters is worth it.

b) Playability impact by usage
To make this bug work best the framerate has to be worst. Now running a 3D realtime game with a low framerate is IMO most undesirable. Low FPS is tolerable for a short period of time i.e. to solve very texture- or effect-heavy rooms as some mods feature them but it's nothing i want to experience for the entire play. I rather adjust game settings for a better framerate, even switch PC's or hardware than force me thru an unsatisfying experience. Had to deal with enough of this in the 80's and 90's and today there is absolutly no need for this anymore.