Item Randomizer run

2014-07-01 09:10:40 pm

I noticed there is a way to randomize items in other metroid games, namely Metroid prime. Looks like a fun challenge, just wondering if there is a program to create this type of patch for zero mission?

Basically it would randomly rearrange all normal items (except morph ball, missiles, and bombs), and rearrange all power ups.

Thread title:

ArXyn

2014-07-01 09:32:57 pm

Last I heard, someone had started creating a randomizer. I don't know what ever came of it.

MetaEdge

2014-07-01 09:59:41 pm

I wonder how someone would even go about this, where you would even start.

altf4towin

2014-07-02 07:30:56 am

Look at the Super Metroid one and just swap the stuff around?

kirbymastah

2014-07-02 11:50:18 am

Biosp4rk has been looking into it but there're a lot of iffy things that make it difficult. I think he told me on skype that all major upgrade sprites are also tied to the corresponding chozo statues so it'd be really annoying to separate and swap them; there are probably other problems with it as well.

BioSpark

2014-07-02 12:33:53 pm

someone with more knowledge than me could probably do it, but i think the problem is that super has been hacked for many years while fusion/zm hacking is still kinda primitive. some of the difficulty comes from the fact that power ups are sprites while expansions aren't.

ArXyn

2014-07-04 11:14:09 pm

If the expansions aren't sprites, then what else can they be?

MetaEdge

2014-07-05 12:52:11 am

I would guess just tiles (like the background). And the programmers just change the tile after collecting it. Don't know why they would do it this way, should be consistent. Unless one is animated and the other isn't. I should probably check this out on an emulator to confirm. I've never bothered looking to see how it's setup before

BioSpark

Edit history:

BioSpark: 2014-07-05 02:39:32 am

BioSpark: 2014-07-05 02:39:24 am

BioSpark: 2014-07-05 02:39:19 am

2014-07-05 02:39:02 am

yeah, expansions are just animated tiles. however, i realized that i could just make expansions be sprites when they need to be, and i could probably make power ups be animated tiles when they need to be. i'm still not really capable of doing that at this moment, but i'm pretty sure it could be done.

altf4towin

Edit history:

altf4towin: 2014-07-06 03:18:02 pm

altf4towin: 2014-07-06 03:17:36 pm

altf4towin: 2014-07-06 03:17:25 pm

altf4towin: 2014-07-06 03:16:55 pm

2014-07-06 03:14:45 pm

It's possible to manually swap one spriteset with another, but I only tested it swapping the zoomers in starting room with power grip, which actually works as expected. It did however change other sprites unexpectedly, so early days. However, I'm working on something else on MZM so I haven't factored the time to test it more, but it is possible. I just haven't dug very far yet.

MetaEdge

2014-07-06 06:21:08 pm

Be careful with the powergrip. I think not collecting a item at that moment in the game fails to trigger the flag that removes the enemy that blocks you from the right most part of norfair.

Played one rom hack that forgot to adjust for this so the game stops at that point :(

kirbymastah

2014-07-06 10:13:59 pm

maybe the hack can just completely do away with that enemy? :P

BioSpark

2014-07-07 01:03:35 am

the hack would need to remove the vine in norfair and fix the shootable blocks tied to the unknown items. this would actually be the easy part. i might start looking into switching abilities and expansions around.

kirbymastah

2014-07-07 01:27:31 am

How would you work out automatically getting varia after you get gravity? IIRC varia suit disappears after stealth is done?

also would anything get screwed up if you were missing some of the unknown items at the end of stealth?

BioSpark

2014-07-07 01:40:39 am

i wouldn't let you get gravity, just the unknown item for it, so there shouldn't be any problems.

as far as i know it should work just fine, but i can test that later.

altf4towin

Edit history:

altf4towin: 2014-07-09 05:05:03 pm

altf4towin: 2014-07-09 04:09:28 pm

altf4towin: 2014-07-09 03:08:30 pm

altf4towin: 2014-07-09 02:46:14 pm

2014-07-09 02:43:57 pm

I just tried it, the only unknown item you *need* is plasma beam to damage the omega pirates at the end, otherwise it's doable, albeit difficult. Outside of bombs and power grip, you don't need any other items.

So not "rolling" space jump won't cause you to be stuck, and gravity can be missed entirely. Varia does indeed disappear when you get gravity.

There are two ways as far as I see to achieve it: a ROM hack that somehow randomizes everything on boot, or an external program that handles everything and spits out a ROM.

Edit: I started on a minimal ROM hack to see the worst possible "rolls", only replaced the power grip vine with a zoomer for now.

Edit 2: Not sure if this was known or not, but the vine respawns despite having the sprite removed. Not sure what causes it to return yet.

Edit 3: I found a simple method to get a randomizer sorted now. By simply generating a random value and adding it to the inv addresses, 0x0300153C/D or 0x03000153E/F, you gain the item. Here is a good reference of the item values, as well as the other addresses. Using memory.registerwrite, you can setup a hook to write the random value to the addresses rather than what's expected.

The biggest problem as I see, outside of the "make sure you have x items" logic, is aesthetics, which is why I think having a ROM hack/external program to physically move the sprites would be best in the long run. Nevertheless, this works for now for experimentation. I've made a github repo with what I have so far here, feel free to fork/push/spam with hate.

I just tried it, the only unknown item you *need* is plasma beam to damage the omega pirates at the end, otherwise it's doable, albeit difficult. Outside of bombs and power grip, you don't need any other items.

So not "rolling" space jump won't cause you to be stuck, and gravity can be missed entirely. Varia does indeed disappear when you get gravity.

There are two ways as far as I see to achieve it: a ROM hack that somehow randomizes everything on boot, or an external program that handles everything and spits out a ROM.

Edit: I started on a minimal ROM hack to see the worst possible "rolls", only replaced the power grip vine with a zoomer for now.
[img]http://i.imgur.com/lzYR2FV.png[/img] [img]http://i.imgur.com/dwtDMn1.png[/img] [img]http://i.imgur.com/Pjg0LQE.png[/img]

Edit 2: Not sure if this was known or not, but the vine respawns despite having the sprite removed. Not sure what causes it to return yet.

Edit 3: I found a simple method to get a randomizer sorted now. By simply generating a random value and adding it to the inv addresses, 0x0300153C/D or 0x03000153E/F, you gain the item. [url=http://datacrystal.romhacking.net/wiki/Metroid_Zero_Mission:RAM_map]Here[/url] is a good reference of the item values, as well as the other addresses. Using memory.registerwrite, you can setup a hook to write the random value to the addresses rather than what's expected.

The biggest problem as I see, outside of the "make sure you have x items" logic, is aesthetics, which is why I think having a ROM hack/external program to physically move the sprites would be best in the long run. Nevertheless, this works for now for experimentation. I've made a github repo with what I have so far [url=https://github.com/elken/mzm-things]here[/url], feel free to fork/push/spam with hate.

BioSpark

Edit history:

BioSpark: 2014-07-09 05:28:08 pm

2014-07-09 05:26:07 pm

i believe an external program that modifies a rom would be best. not sure why you're giving yourself random abilities that way.

swapping expansions is something i already know how to do. it's swapping expansions for abilities and abilities for expansions that's more problematic. i need to figure out how both of these are stored graphically, then do some asm modifications to modify the item given to samus.

of course, i could simply remove the chozo statue and add a lone missile tank, for example, but that's no fun.

altf4towin

Edit history:

altf4towin: 2014-07-09 05:32:42 pm

2014-07-09 05:30:45 pm

I was already doing something else, and I sort of spun it off of that. At least we know now that it is 100% possible now. I will look harder tomorrow what causes the vine to respawn, I'm thinking it's Ridley-related but I can't say for sure, and I'll try and have a go at swapping the good stuff.

That's faaar too easy, where's your low% hard mentality? :p

BioSpark

2014-07-09 05:35:37 pm

the vine should not respawn if the sprite was removed properly.

also now that i think about it, it might be easier to leave the abilities as sprites when they replace an expansion, but that wouldn't work for expansions hidden under shootable blocks. new clip data would have to be added for each ability.

altf4towin

2014-07-09 05:38:09 pm

Meh, it's all from stuff I've learned today, I'm far from BioSmart ;).

Can't you still swap the sprites? How do the blocks work? Don't they just use a pointer to the sprite data?

BioSpark

2014-07-09 05:42:53 pm

not sure what you're asking. the abilities are sprites, while expansions are tiles with an associated clip data. the clip data tells the game how samus interacts with the block if she touches it. in the case of expansions, it gives samus missiles/energy/pbombs and then changes the block to nothing.

basically i'll need add 4 new sprites for each type of expansion, and add new tiles with new clipdata for the abilities.

altf4towin

2014-07-09 05:45:12 pm

By blocks, I meant the shootable blocks on abilities.

BioSpark

2014-07-09 05:55:29 pm

those blocks have a clip data that could basically be called "hidden x tank". they change into the appropriate tank when shot.

altf4towin

2014-07-09 05:58:08 pm

Couldn't you just change where that points to? Or would you still have to change the clip data and sprite?

BioSpark

2014-07-09 06:00:27 pm

yes, it would require a new clip data and animated tile (not exactly a sprite). this could always come later though. just adding the sprite to the room would be easier for now