don't click here

Glitch in Sonic 1 Japanese version

Discussion in 'General Sonic Discussion' started by Ambil, Jul 6, 2005.

Thread Status:
Not open for further replies.
  1. Ambil

    Ambil

    I want that heinous hedgehog hammered! Member
    893
    0
    0
    Spain
    I just was playing a normal game in Sonic 1 Japanese version when accidentaly found this weird bug in the beginning of Scrap Brain Zone, act 1.

    [​IMG]

    Sonic is ledging in a place that he is not supposed to. This glitch is not easy to detect, because you usually run and jump to avoid falling to abyss in this scene of the act.

    Which is the cause of this technical bug?, I wondered, and opened ESE II to search inside the level mapping. Below the block that Sonic is standing on there is a Robotnik-shaped solid block, but I'm not sure if this piece is the reason that makes Sonic to ledge.

    [​IMG]

    I am completely dissapointed to not be able to edit the Sonic 1 Japanese savestate in SonED, and remember that ESE does not save your progress in Sonic 1 related stuff. So, the only I can offer you to discuss is a Gens savestate in the accurate point of the stage.

    (To Simon: Please trash this topic if this issue was already known in the Scene)
     
  2. Miles3298

    Miles3298

    Member
    557
    3
    18
    This is old news for people and new news for the community I'm guessing.

    Soic 1 likes to play with collision which usually gets Sonic burned. This happened to me alot on SMC. o.o
     
  3. Aurochs

    Aurochs

    Единый, могучий Советский Союз! Tech Member
    2,343
    0
    0
    Whatever catches my fancy
    The Robotnik blocks probably have something to do with those platforms. As for the bug, I'd say that it's just that there is a small break in the collision info there, or perhaps the block not meeting properly. S1 has a lot of those, I think.
     
  4. Rika Chou

    Rika Chou

    Tech Member
    5,272
    164
    43
    Lil glitches like that occur in all the genesis Sonic games. It can be easily fixed my editing the collision index for that level.
     
  5. LOst

    LOst

    Tech Member
    4,891
    6
    18
    The Eggman block (used for extended collision) is too far down. And the trapdoor is too far to the left to be interacting with Sonic at the point you took that screen shot.

    This looks like a tile collision bug to me. Maybe a mistake that can be fixed? It may also be an error in the Sonic player code. Reading collision is heavy work, but Sonic 1 does it better than Sonic Advance 2. This little bug is nothing compared to the collision errors in Sonic Advance 2 and 3 where Sonic's speed sometime just disappears for no reason, and Tails get stuck 17-33 pixels below ground when flying down too fast.
     
  6. Sakura Courage Solo

    Sakura Courage Solo

    I am a Woodpecker! Except in Dirt! Member
    1,037
    0
    0
    Lava Reef Zone
    A Sprite-Based Dollmaker and a Card Game
    Bah, let's face it, the only GBA Sonic game that ever had anywhere NEAR proper collision was Sonic Battle! But yeah, like LOst and Rika said, probably just a missing bit of collision info in the collision points, or the tiles are very slightly misplaced, but I'd say that it's the collision bug, since the tiles look perfectly aligned to me.
     
  7. Kles

    Kles

    Member
    The collision bug is misaligned to the left or the right though?
     
  8. Qjimbo

    Qjimbo

    Your friendly neighbourhood lemming. Oldbie
    Very observant Ambil, although like the others have said this bug appears in several places throughout the games. Still very nicely presented I have to say.
    AMBIL FOR FULL MEMBER *gets out pompoms*
     
  9. LocalH

    LocalH

    roxoring your soxors Tech Member
    3,303
    26
    28
    wouldn't you like to know
    Guitar Hero II Deluxe
    I'm pretty sure the game does that simply because you're standing on the edge of *something*, even if it doesn't visually look like it. For example, in GHZ, where you have the breakaway platforms connected to solid platforms, if you stand on the edge of the solid part without touching the breakaway, then Sonic will ledge. It usually seems to happen when an object and a piece of the level are butted up next to each other - the game doesn't seem to care that there is an object there while checking to see if it should use the ledging frames of animation.
     
  10. Dr. Ivo

    Dr. Ivo

    Professional Reverse Engineer Tech Member
    LocalH is right. When Sonic is riding on an object (the Robotnik block, in this case) normal path collision is completely ignored. He topples because he is at the edge of the Robotnik block.

    Ridable object "edges" are detected by comparing Sonic's center with left and rightmost extentions.

    Path edges are detected by using three collision hotspots whenever Sonic is standing -- one to his screenwise left, one slightly off center towards the direction he is facing, and one to his screenwise right. If an edge hotspot and his middle hotspot can't find solid path directly below, the ledge toppling animation is shown.
     
  11. Trujin

    Trujin

    The Bad Seed. Member
    But if you can notice in this image of Sonic in the ledge animation he is afew mm away from the Robotnik block. Compared to the screenshot of ESE.
     
  12. LocalH

    LocalH

    roxoring your soxors Tech Member
    3,303
    26
    28
    wouldn't you like to know
    Guitar Hero II Deluxe
    If I remember correctly, the objects used in those circumstances are usually a 2x2 square of those blocks (and thus 32x32 pixels), and not just the single 16x16 Robotnik graphic. If I'm correct, then that places the right hand side of the block directly under Sonic's feet. And if the block extends upward from the position of the graphic in ESE, then it looks like it's just close enough to cause Sonic to react to it. I don't actually think that this particular instance is what I said earlier, though, although it does happen within the game in other places as I said. It seems the ledging only begins between X coordinates 029C and 029F. However, if you're already ledging, and you move to the right a pixel at a time, Sonic will continue ledging until 02AB. Sonic also immediately stops ledging if you move left to 029B. The ledging that I was originally talking about (between objects and level) is at 0281, where Sonic ledges regardless of the trapdoor position.
     
  13. LOst

    LOst

    Tech Member
    4,891
    6
    18
    [​IMG]

    If you look here, there is nothing wrong with the collisions, so it is the Robotnik block, or the trap door for sure.
     
  14. I don't recall reading about that glitch until now. I thought I did, but it was just about a weird tv hidden within a wall somewhere in Scrap Brain. It loads a piece of a graphic with the wrong colors in a weird position above and to the right of the box. Are there more gltiches like this in Scrap Brain Zone? They probably happen elsewhere, but is it more often in Scrape Brain than other levels?
     
  15. ICEknight

    ICEknight

    Researcher Researcher
    Heh, neat.
     
  16. LOst

    LOst

    Tech Member
    4,891
    6
    18
    Yea ^^;

    Still much work to do.
     
  17. Tweaker

    Tweaker

    Misfit
    12,389
    1
    0
    A glitch in Sonic 1 Japanese? HOLY SNAPS CALL THE SPARGEL SQUAD

    It's the trapdoor. Try moving it down a few pixels and test the result. I've had this problem before as well while making levels of my own.
     
Thread Status:
Not open for further replies.