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oh cool, you found something!
Well now, as you play the game, if you know when the RNG updates, you can kind of predict the future right? For example you will know what the RNG will be 30 frames into the future, and will know how far you are from getting a 1-up or any item you want and how much you need to adjust?
That was my original thought anyway, but maybe the cycle you found can be useful in other ways?
EDIT:
To expand on this a bit. You already know the RNG seed for each level and how the RNG formula works, so if the RNG simply updates once per frame, what you can do is map out the item that will appear at every frame in the level simply by running the RNG code and matching the result to the table you made.
Then you just need to kill an enemy on the right frame, which you now already know.
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http://tasvideos.org/userfiles/info/22561027219611492
Here is my first attempt. I saved more frames then what I thought since the trick also works in the conveyer belts and saves about 3 frames each jump in that area. I'm glad I found this trick, as this run was one I was concerned about actually being able to improve.
I also included Diman's jump.
EDIT: second attempt much more optimized then the first one
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I found a small trick in the river level that lets you jump out of river without losing your horizontal velocity for so long.
Basically just let go of right for a frame when you start jumping.
It saves about 2 frames every time you do it. There are lots of jumps in that level, so it should add up pretty quickly.
I suppose I will continue off Randil's WIP and see what I can do. Also have to remember to add Diman's trick at the end too.
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@samsara: I think that would be a good idea. Well, if more people are interested in taking on runs. Right now its just my pipe dream, so it would be a pretty lonely channel. 8D
I found a trick in Jackie Chan that looks like it will save about a second in the river level, so looks like that is the next target!
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I was about to start working on this run, but here it is already done!
Is there anything still keeping this from going to the workbench? I can help out if anything needs work.
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Samsara wrote:
Would this project benefit from something more actively collaborative, like a Skype chat or a dedicated IRC room?
I didn't really have anything formal in mind beyond this thread, but I'm certainly willing to team up with anyone who wants to work on one of these. Especially some of the longer ones, as runs of more than an hour or so seem much more rare recently.
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Here is my latest WIP, I am pretty comfortable with it up to the last boss.
I can't seem to improve blublu's last boss fight, but it seems like it should be possible.
Maybe a Wizards and Warriors II situation where more eyes looking at it will lead to quick improvements.
So anyone who wants to give it a try can be co-author, I really wonder how much it can be improved.
http://tasvideos.org/userfiles/info/22507545392735988
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Nicos wrote:
great improvement, yes vote
on the emulator side in tehberral's encode the second counter (lag counter) seems to only count loading zones and not slowdowns ( frame drop or real LAG? )
am i correct or do i get something wrong there ?
oh good point I forgot to mention this.
The game doesn't lag in the traditional sense, it just does less each frame when there is too much to keep track of. I'm not sure of the details, but I think it is something like only updating a fixed number of actors on the screen per frame.
I'm not sure of any other examples of games that do things this way to compare it too. Can anyone think of any?
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The item you have to go get in the final level is a key. Using that key on the locked door where I drop the teleporter triggers a cutscene, which is what tells the game you are in the final area. (You might notice that an enemy that is standing right next to me disappears after the cutscene.) So in this particular instance it is not skippable.
You land on that wall by turning around after dropping off the platofrm above you, a rarely used move by itself. Another glitch in a game full of glitches.
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Thanks for the encode Tehberral!
Taking damage, let's see...
A few times taking damage knocks you back in a convenient way, such as falling down to a platform without having to turn around, take a step, turn back around, and drop down, you'll see this in level 2.
A few times it is for the invincibility frames that let you get by a group of enemies, you'll see this in the tower.
One time it was unfortunately just unavoidable at the start of level 7, although it wasn't so bad as it knocks you forward to a convenient spot.
And yes combat in this game is not fun at all, it is incredibly rare that killing an enemy is worth while, the only time this happens is in level 2 with one of those sentry spheres, that would otherwise prevent you from doing a wall clip, and the enemies in level 1 that would otherwise shoot you, but they only take 1 shot.
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well despite some hiccups with bizhawk I managed to finish the run.
http://tasvideos.org/userfiles/info/22405820945784714
may or may not be more I can improve, I will have to look it over a few more times before submitting.
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Bizhawk keeps throwing this message after a fatal error of some kind.
Any idea what is going on? Version 1.9.4 running sega genesis.
The error occurs when I am playing back a movie in TASstudio after loading a savestate.
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I am trying to use bizhawk 1.9.4 TASstudio and am noticing some significant slowdowns (to 4 fps) after getting a few minutes into the run. The game is Flashback for sega genesis.
Is there a way to limit green frames? I can't seem to find the setting. Also what does clock throttle setting do?
Any other tips to speed up TASstudio appreciated.
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Well after a while here finally is WIP 1. Even though the file is long, only the first minute or so is in there.
http://tasvideos.org/userfiles/info/22316796280079805
I guess I needed a break, after umihara kawase I had run out of motivation.
Plus the controls of this game took me a long time to actually figure out.
But anyway the rest of the run I think will go pretty quick now. I am a couple of seconds ahead of the old run I believe, pretty much copying the movie I posted, but with slight improvements.
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ALAKTORN wrote:
Alyosha wrote:
One question I have wondered about is if there is another practical way to TAS besides emulation, like hardware direct TASing?
High quality Mario Kart Wii TASes have been made on the Wii itself. There are cheatcodes to copy ghost input and slowdown gameplay. TASing on emu is far better if possible, though.
Oh, that is a cool feature, too bad more games don't have that.
Also for the Rockman ZX rng question, do you know the addresses for the IDs for the drops? I'm pretty sure only 3 bytes are involved in picking the drop, so maybe you can make a save state one frame before killing an enemy, and make a LUA script to simply enumerate through the ~16 million RNG possibilities to get a complete table? It won't help in manipulating those RNGs to come up, but maybe you can see a pattern.
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Scepheo wrote:
Masterjun wrote:
Ever since I wrote this script for predicting RNG in this run I wondered if the formula could be reduced. [...] So my question is: is it possible to reduce the formula or function to a simpler one?
Yes. Alyosha already noted how a single step in the inner loop behaved, which is basically a linear feedback shift register. For the code below, I used the standard bit library that comes with Lua 5.2, but any implementation or bit operators would do. I also, like creaothceann already mentioned, considered your RNG to be a single 16-bit value, rather than two bytes, which makes manipulation a lot simpler.
Language: Lua
require 'bit'
local function myRNG(rng)
local b
for i = 0x01, 0x0B do
b = 1 - bit.band(1, bit.bxor(rng, bit.rshift(rng, 1), bit.rshift(rng, 15)))
rng = bit.bor(bit.lshift(rng, 1), b) % 0x10000
end
return rng
end
Nice, question answered! I guess this thread accomplished something!
Proofs of complexity class are a bit beyond me, although I do wonder if there will ever be a game that is proved to be beaten as quickly as possible?
One question I have wondered about is if there is another practical way to TAS besides emulation, like hardware direct TASing?
As there is desire to TAS games on newer and newer consoles, it seems unlikely that emulation will be able to keep up at reasonable speeds on home computers, is there a workable alternative?
Any more little game mysteries anyone can think of too?
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That's a clever table representation, pretty cool.
I don't really see where the property that the rng goes through every possibility (except the AA-55 cases) comes from, but I guess I'll leave that for people who are better at math.
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@Masterjun:
That is a neat property. Well the function itself can certainly be simplified with more local variables.
If you write RNG1=A7,...,A0 and RNG2=B7,...,B0 then after 1 of the 11 cycles you get
RNG2=B6,...,B0,A7
RNG1=A6,...,A0,NOT(XOR(XOR(A0,B7),A1)) (if I did all my math right)
But simplifying the loop, I think not, since after 11 cycles, RNG2 will look like:
A3,A2,A1,A0,NOT(XOR(XOR(A0,B7),A1),.... and RNG1 will be a mess.
@ALAKTORN:
I just mean that if DeSuMe had a trace logger you could find out all of that stuff pretty easily (compred to trying to deduce what is happening.)
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ALAKTORN wrote:
Alyosha wrote:
How about some more practical problems that people really want to seem solved?
Figure me out how Mega Man ZX’s RNG works.
What would you like to know about it? I found the work you've done so far and I did a little testing. As far as I can tell the fourth byte has no impact on what is dropped. It also seems that all enemies (at least in the intro level) have the same drop characteristics. I tested with RNG B4B3A413. Hard to tell exactly how it is being used though.
I guess this would be kind of trivial with a trace logger type utility in the emulator, so I would say that is an open problem in R&D.
Bizhawk keeps throwing this message after a fatal error of some kind.
Any idea what is going on? Version 1.9.4 running sega genesis.
The error occurs when I am playing back a movie in TASstudio after loading a savestate.