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Adding and deleting objects with out using Soned 2

Discussion in 'Engineering & Reverse Engineering' started by stormislandgal, Aug 22, 2005.

  1. stormislandgal

    stormislandgal

    It's not a phase! Tech Member
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    I'm sorry if this is old or already documented, but I saw nothing like this on any hacking guide for Sonic 2. Plus I'm proud I found something that could potentially have a large impact on a rom hack.

    Hey there everybody. I've stunned myself yet again. I was screwing around in hex the other day and I managed to find out how to change the pointers for level object data. I spent almost an hour picking apart the following: They're all wrapped up in a little download.
    Object Pointer Table
    Object data for both acts of EHZ
    Object data for both acts of CPZ
    Object data for both acts of ARZ
    Object data for both acts of CNZ
    Object data for both acts of HTZ
    Object data for both acts of MCZ
    Object data for both acts of OOZ
    Object data for all 3 acts of Metropolis Zone
    Object data for both acts of Wing Fortress
    Object data for both acts of Sky Chase
    Object data for both acts of Death Egg.
    Object data for both acts of Hidden Palace zone(I think I might have just act 1.)
    I left the others out because I was getting a little disorientated by messing around with them.

    With this guide you can:
    Nearly double the size of any zone by adding objects.
    Have enough room to place objects for the "lost levels" Keeping the data in the same spot only allowed for one zone.
    Have 2 acts in SC and WF(for that dumb cutscene at the end, you can make it fly up to another airplane by editing the level layout)
    Delete objects from levels.

    The Readme/Guide is packed in with the download. BE SURE TO READ IT. ALL OF IT. Otherwise the results WILL NOT be pretty.

    PS: To anyone who has the power to add things to the Sonic Community Hacking Guide, would you take this into consideration?

    Just a note: This is my first experience with working with hex without any guides, so feel free to idolize me. =P *stabbed*

    EDIT: Spelling errors... I need to slow down on the keyboard...
    EDIT2: Yes I am aware of Soned 2 being able to do this so...
     

    Attached Files:

  2. Quickman

    Quickman

    be attitude for gains Tech Member
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    ROM expanding is a highly redundant method of ROM hacking. I for one recommend using a split disassembly over this method. (Is it REALLY that much trouble to doubleclick build.bat? The process takes a minute - A MINUTE - to compile and build the finished ROM. It takes almost as long to actually load up the ROM in Gens.)

    Not to say that this isn't a useful strategy - for those neophobes who refuse to use split disassemblies (perhaps their religions forbid them, I don't know) it's a useful method (although I still think ROM expanding is not a good method of hacking - you're far better off editing things in situ, and that doesn't create a bloated end result.)
     
  3. StephenUK

    StephenUK

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    Quackshot Disassembly
    SCZ and WFZ couldn't have 2 acts without heavy programming coz the game doesn't seem to like it when you try to go to these zones. Try it and see for yourself.
     
  4. stormislandgal

    stormislandgal

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    I was about to say that in my initial post, but my internet whipped my ass.

    This also includes a step by step process that allows for a non-expanded rom to do this, but warns you that you will screw yourself out of using utilities.

    EDIT: I might pick the rings apart, but then there is that 255 ring limit, so that would be a little pointless. And with the space you freed using my method, you could put rings in ALL of those empty zones. So picking them apart would be kinda pointless...
     
  5. Rika Chou

    Rika Chou

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    Your wrong there.

    WFZ act 2 works by default, sonic even has a starting location.

    SCZ act 2 will work if you change a few bytes. Change the 6 bytes at 0xC408 to 0C78 1000 FE10. (thanks ultima) Now you just have to edit the levels size and wha-la.
     
  6. Hivebrain

    Hivebrain

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    Don't forget that objects must be listed in the order of their X-coordinates, otherwise some objects will fail to load. Look at the data in a hex editor and you'll see what I mean.

    Using INCBIN instructions in your ASM instead of using combine.exe speeds things up considerably. My S1 disassembly takes 2-3 seconds to compile.
     
  7. StephenUK

    StephenUK

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    Quackshot Disassembly
    Well I think I'll be making use of that then. Thanks for the info.
     
  8. The Mighty Boosh

    The Mighty Boosh

    Stupid like a FOX! Member
    There's a problem I noticed with WFZ act 2. Once you get up to the part where robotnik is, the background starts scrolling at super speeds, and screws up basically. So you'd probably have to end the level before that point, or fix that if it's simple enough.
     
  9. stormislandgal

    stormislandgal

    It's not a phase! Tech Member
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    Hmm, Thanks Rika, I'll make use of it too.

    Yes, but I've had problems with building before, and I'm sure others have too. Plus I designed this for novices, those who don't exactly have all the hacking knowledge to work with SonEd2.
     
  10. .hack//zero

    .hack//zero

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    Working on a vulkan game engine for fun. Learning Ray-Tracing.
    I gotta remember to use this too.