FractalFusion can explain this much better than I can, but basically he found which pattern Bospider will give on each of the game's rng values, mapped out the game's ~43,000 value long sequence, and found out the number of frames it takes to kill Bospider given each pattern.
The rng sequence advances one frame at a time, and will skip a value on each frame that you kill an enemy as well as each frame you create a dust sprite from sliding down a wall.
Prior to phantom grabbing the door in this stage, I was very limited in which enemies I could kill/ignore so that I could get an extra life to do the platform grab at the beginning of the stage(these are extremely rare and I couldn't use life energy since I was weakening myself for the vile encounter), a good vile pattern, and a viable drop for the door grab. I had to go back and redo the majority of the stage several times to get everything to fall into place since my rng around the time of the door grab was particularly bad(there wasn't another life energy for miles before/after the frame I got this one on).
So from this point onward, given the frame that I was on in the rng sequence, killing as many enemies as possible and creating the max number of wall slide dust sprites during downtime just happened to coincide with getting me to the fastest Bospider pattern anywhere within close proximity. Something like 20-30 frames later was the nearest optimal pattern, but considering I had already killed everything/created max dust sprites, my only manipulation option left would have been to delay entering Bospider's door which would have resulted in a net time loss since the pattern was so far away.
It might be possible to gain a net time save of a small number of frames from utilizing the nearest optimal pattern if I kill more helmet heads to the detriment of my movement in the final section, but this is very questionable. Not only does firing extra shots in this section cause lag, the helmet heads don't take damage until you turn your back to them, you must also item avoid drops(for lag reduction and especially so you don't refill ammo), and you have to use c-sting because of the initial invulnerability of the enemies.
And just to give people an idea of how rare optimal Bospider patterns are, there hasn't been a published mmx tas with less than 3 crossovers on the initial descent since at least before FractalFusion's any% tas from 2006 (I haven't watched any of the obsoleted any% TASes, but I doubt they got the optimal pattern either). Given the way rng manipulation in mmx works, sometimes you have to just take what is given to you.
Yeah, Lua script.
So after using a different strat to eradicate the room before Bospider, create an additional dust sprite, and delay my movement by a handful of frames, I was able to make it to the nearest straight-down pattern in the sequence in order to net a 2 frame save, lol.
By the way, after testing more door phantom grabs, I now understand by what parrot14green means by the distance between phantom grab door and normal door.
If the door is first produced in the boomerang (not when X touches it) too far to the left, the boss won't spawn.
So, this rules out any bosses where the door can only be approached by horizontal scrolling, which are Octopus and Mammoth.
For Kuwanger's case, if you phantom grab the door so that it scrolls very little and you can see the ladder, then Kuwanger won't spawn. I'm pretty sure now Hetfield90 has the best strategy.
For Penguin's case, you'd have to try phantom grab from below. But this is the farthest right I've been able to get the door. Even if you were somehow able to escape from the wall, Penguin still won't spawn. I tested by teleporting X into the room.
Example: http://tasvideos.org/userfiles/info/21001241970948079
For Chameleon's case, you'd be very far away once you phantom grab from below.
Example: http://tasvideos.org/userfiles/info/21001253808618399
I don't think it is possible to ice sled zip in Mandrill and then do boomerang phantom grab. You'd have to be in the wall to load the gate and you can't stop while in the wall.
I've stopped testing, so if parrot14green doesn't come up with anything, I don't think any skip glitch will appear any time soon.
ALAKTORN wrote:
Huh, the optimal pattern is that rare is it. How do you keep track of what value in the sequence you are in the RNG? Is that a Lua script?
I have a supplementary table (which is too large to put into Lua script or post in a message) which has all the RNG values, their position in the sequence, the wire crossing pattern generated when it appears as "Current value" in the Lua script, and the number of frames from Bospider descent to when he opens his eye. (Technically, the value at "Current value" doesn't generate the pattern; it is the last RNG value used after the pattern is generated. A value 10 or so positions in advance starts the generation of the pattern.)
This table can be generated in any programming language.
There are about 1000 values out of the 43534 which give perfect Bospider (no crossing). This actually differs from estimation by true randomness (3/512 probability, or about 255 values); the reason for this is because the RNG is flawed. If a value is the same parity (even or odd) as the previous value, then the next value will very likely be the same parity. Likewise, if a value is of different parity as the previous, then the next will very likely be different. This affects the wire pattern greatly. Ideal patterns rely on long sequences of values that switch between even/odd.
But for the same reason, many of the ideal values all tend to clump together. So there are a lot of regions where ideal values don't appear for a long time.
As for the pattern Hetfield90 manipulated, the RNG value he used is actually about 20 positions prior to a perfect value. Actually, there are a whole bunch of perfect values clumped together in that region; this is because when the RNG value is hex FFFF, the following values will be FFFE, FFFD, FFFC, FFFB, FFFA, FFF9, FFF8, ... , FFAA (yes, this is another flaw in the RNG) and every four values will give a perfect pattern.
Now that we know that we are 20 positions short, we can of course go back to the last time we can advance the RNG 20 (or more) positions without losing time and redo everything from there. The problem is, I don't think Hetfield90 wants to do that, considering "last time" is back at Armadillo boss fight. Hex-editing input to change RNG is not an option.
Edit: Oh, I misunderstood Hetfield90's last post. Apparently he did get to the next perfect pattern, but at the cost of a lot of frames in the previous room.
“There are about 1000 values out of the 43534”
I’m actually confused by this: why are there 43534 values total? If the RNG is 2 bytes, shouldn’t there be 65536?
“There are about 1000 values out of the 43534”
I’m actually confused by this: why are there 43534 values total? If the RNG is 2 bytes, shouldn’t there be 65536?
Based on whatever initial seed there is, some values are likely impossible to get to. Not many games use PRNGs that cover their full space, so it's not too surprising that this one has a period less than the full 2-byte space. If anything, I'd say it's surprising they managed to get more than 50% of the space.
Joined: 11/26/2010
Posts: 454
Location: New York, US
Omnigamer wrote:
ALAKTORN wrote:
“There are about 1000 values out of the 43534”
I’m actually confused by this: why are there 43534 values total? If the RNG is 2 bytes, shouldn’t there be 65536?
Based on whatever initial seed there is, some values are likely impossible to get to. Not many games use PRNGs that cover their full space, so it's not too surprising that this one has a period less than the full 2-byte space. If anything, I'd say it's surprising they managed to get more than 50% of the space.
Hey Omni? I know this might be a stupid question but, what is the P in PRNG?
Hey Omni? I know this might be a stupid question but, what is the P in PRNG?
Psuedo
*Pseudo.
:P
I guess that makes sense Omni. I’ve never really had to look at an RNG that deeply except for in Advance Wars: Dual Strike, and I think that one uses the full 65536 values.
“There are about 1000 values out of the 43534”
I’m actually confused by this: why are there 43534 values total? If the RNG is 2 bytes, shouldn’t there be 65536?
Better RNGs (such as linear congruential generator and linear feedback shift register) would have periods which are powers of two, or very nearby. Any so-called RNG that was put together in an hour has no such harmony (i.e. it may miss out on whatever number of values).
Joined: 11/26/2010
Posts: 454
Location: New York, US
Hey Parrot14gree, can you reproduce the glitch from the video I posted the sends you to the boss room in Boomer Kuwanger's stage from the ladders area by falling into the pit? The person who had the video deleted it from their You-Tube Channel for some reason. I wonder if there are any other death skips as well?
I though I'd ask you because Hetfield90 is gonna be doing the Any% TAS next and will be submitting the 100% TAS later today.
Hey Parrot14gree, can you reproduce the glitch from the video I posted the sends you to the boss room in Boomer Kuwanger's stage from the ladders area by falling into the pit? The person who had the video deleted it from their You-Tube Channel for some reason. I wonder if there are any other death skips as well?
I though I'd ask you because Hetfield90 is gonna be doing the Any% TAS next and will be submitting the 100% TAS later today.
Hey lxx4xNx6xxl, do you mean this post?
In fact the death trick doesn't save time.
X start in the top tower cause he has gone to there already.
And I had explained it after your posted.
If I misunderstand your meaning,pls let me know.
Joined: 11/26/2010
Posts: 454
Location: New York, US
parrot14gree wrote:
lxx4xNx6xxl wrote:
Hey Parrot14gree, can you reproduce the glitch from the video I posted the sends you to the boss room in Boomer Kuwanger's stage from the ladders area by falling into the pit? The person who had the video deleted it from their You-Tube Channel for some reason. I wonder if there are any other death skips as well?
I though I'd ask you because Hetfield90 is gonna be doing the Any% TAS next and will be submitting the 100% TAS later today.
Hey lxx4xNx6xxl, do you mean this post?
In fact the death trick doesn't save time.
X start in the top tower cause he has gone to there already.
And I had explained it after your posted.
If I misunderstand your meaning,pls let me know.
Well I posted a video that someone sent me and they died falling into the pit by the ladder and after the death they appeared in the boss room. They shot a shotgun ice shot at the ladder before they fell. This has happened to tiki and raijin once before and I was wondering how to replicate it. And yea that was the video. The video itself didn't do a zip which is why I was wondering how it worked or is it just something completely random.
I though I'd ask you because Hetfield90 is gonna be doing the Any% TAS next Well I posted a video that someone sent me and they died falling into the pit by the ladder and after the death they appeared in the boss room. They shot a shotgun ice shot at the ladder before they fell. This has happened to tiki and raijin once before and I was wondering how to replicate it. And yea that was the video. The video itself didn't do a zip which is why I was wondering how it worked or is it just something completely random.
It's happened to me? I don't think so... I dunno about Tiki.
I remember the video. It was actually Parrot14gree's video.
It is as he said. He got the checkpoint before the boss, then escaped the room and went back down, so when he died, he respawned at the last checkpoint. That last post said it happened to me too. I really don't ever remember that happening.
Joined: 11/26/2010
Posts: 454
Location: New York, US
RaijinXBlade wrote:
lxx4xNx6xxl wrote:
I though I'd ask you because Hetfield90 is gonna be doing the Any% TAS next Well I posted a video that someone sent me and they died falling into the pit by the ladder and after the death they appeared in the boss room. They shot a shotgun ice shot at the ladder before they fell. This has happened to tiki and raijin once before and I was wondering how to replicate it. And yea that was the video. The video itself didn't do a zip which is why I was wondering how it worked or is it just something completely random.
It's happened to me? I don't think so... I dunno about Tiki.
I remember the video. It was actually Parrot14gree's video.
It is as he said. He got the checkpoint before the boss, then escaped the room and went back down, so when he died, he respawned at the last checkpoint. That last post said it happened to me too. I really don't ever remember that happening.
Oh OK maybe I misread on the chat it was a long time ago. I guess you linked me the video then. Oh if it was Parrot14gree's video then never mind I completely got things mixed up then. It was so long ago its hard to recall and I really don't remember the video well the only thing I remember is it being short and it was as I explained it. He may have zipped and not recorded it then I guess. If I'm wrong sorry for the confusion everyone.
It seems like more fast than before.
http://dehacked.2y.net/microstorage.php/info/160629840/Mega%20Man%20X%20%28U%29%20%28V1.1%29-SF1_Phantomgrab1-BKskip7.smv
1.It requires error camera position.
I did it by the charge ice through the thin wall.
2.I zip down to where boss can catch X and shock camera and then Misc. data turn 0 into 1. I dunno why it can change Misc. data.
3.It is likes we mention before.
Boss spawn-->touch the door-->exit door open.
Forget to say,it would wast some frames in Bospider cause the error camera.
You need to jump to spawn Bospider.
I zip down to where boss can catch X and shock camera and then Misc. data turn 0 into 1. I dunno why it can change Misc. data.
I suppose you are referring to the entry for $7E1628 in the RAM Map in the Game Resources section. This is a table of 16 entries of 48 bytes each, for various objects that are not enemies or bullets. The first byte of each entry indicates if the entry is currently in use. These are the kinds of items that can be grabbed with the boomerang cutter. At the moment you are referring to in your movie, the boss door object, which disappears after you go through it, is being loaded again (into the first table entry), due to being at the top of the screen. That is why you are able to go through it again.
I zip down to where boss can catch X and shock camera and then Misc. data turn 0 into 1. I dunno why it can change Misc. data.
I suppose you are referring to the entry for $7E1628 in the RAM Map in the Game Resources section. This is a table of 16 entries of 48 bytes each, for various objects that are not enemies or bullets. The first byte of each entry indicates if the entry is currently in use. These are the kinds of items that can be grabbed with the boomerang cutter.
Yes,this is Misc. data that I mean it.
I knew this cause fractalfusion had explained the phantom grab trick in this thread.
At the moment you are referring to in your movie, the boss door object, which disappears after you go through it, is being loaded again (into the first table entry), due to being at the top of the screen. That is why you are able to go through it again.
Basically the door should far away from X, at least you can't see it in the screen.and then go back until you can almost see it, the Misc. data can turn 0 to 1.
So I don't think it is the reason.
And I test the rest of the boss in sigma fortress, too bad I can't figure out how to let the boss spawn and erroneous camera.I can't skip them.
Here's a pretty fast example of the triple sled zip skip I just made. This ended up being 28 frames slower than the skip in the v2 run up to the barrier leading out of Kuwanger's room being destroyed. So this does not count the additional frames the strat loses to extra health refilling (8 frames, but this only applies to 100%) and the frames lost to having to jump in order to initiate the Bospider fight (which applies to both categories).
I am not too familiar with how zipping works in this game, but Spark Mandrill looks promising. If you can zip your way down to the door, then you can do the same trick in his room by going slightly into the ceiling.
For Chill Penguin you could try to phantom grab the door and leave it somewhere around (05F8, 05B7), then zip into the wall and enter with the camera low enough that he will not spawn, if that is even possible.
I am not too familiar with how zipping works in this game, but Spark Mandrill looks promising. If you can zip your way down to the door, then you can do the same trick in his room by going slightly into the ceiling.
For Chill Penguin you could try to phantom grab the door and leave it somewhere around (05F8, 05B7), then zip into the wall and enter with the camera low enough that he will not spawn, if that is even possible.
The only one zip up chance I know is boomerang catch X, so it's impossible to zip up into the ceiling in Spark Mandrill room.
Or when you do the same trick in Spark Mandrill room(zip down to the floor), the camera is still lock, you have no chance to change misc. data.
For Chill Penguin you mean phantom grab the door but not touching it?I'm not pretty sure.
