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Sonic Jam

From Sonic Retro

SCHG: Sonic Jam
Main Article
Sonic World

Models
Animations
Textures
Sounds
RAM Editing

This is the Sonic Community Hacking Guide for Sonic Jam.

Contributors

(In alphabetical order; if you are a contributor and have worked on a specific part of the guide, feel free to note that.)


Miscellaneous

Pieces of the guide not big enough for their own page should be left here.

3D Vectors

3D Vectors consist of 3 longwords. The upper word of each long can be seen as the integer value of the component; $0001 is 1 unit. The lower word is fractional, out of 65536; $8000 becomes 0.5 units (32768 / 65536 = 0.5). In essence, it's like there's a decimal point after the first word.

This is a bit different for negative values. Like all negative numbers, you're counting downwards, so to convert to decimal, you add 1 to the upper word unless the lower word is $0000, and you subtract 65536 by the lower word, and divide by that. For example, $FFFF0000 is -1.0, but $FFFFC000 is -0.25 (65536 - 49152 = 16384; 16384 / 65536 = 0.25).

Euler Rotation

An Euler Rotation consists of 3 words. Each word rotates around one axis: X, Y, and Z in order (though the three don't always point how you'd expect). $0000 is 0 degrees of rotation, $8000 is 180 degrees of rotation.

I've yet to confirm if all Euler Rotations have the same handedness.

External Links

References


Sonic Community Hacking Guide
General
SonED2 Manual | Subroutine Equivalency List
Game-Specific
Sonic the Hedgehog (16-bit) | Sonic the Hedgehog (8-bit) | Sonic CD (prototype 510) | Sonic CD | Sonic CD (PC) | Sonic CD (2011) | Sonic 2 (Simon Wai prototype) | Sonic 2 (16-bit) | Sonic 2 (Master System) | Sonic 3 | Sonic 3 & Knuckles | Chaotix | Sonic Jam 6 | Sonic Adventure | Sonic Adventure DX: Director's Cut | Sonic Adventure DX: PC | Sonic Adventure (2010) | Sonic Adventure 2 | Sonic Adventure 2: Battle | Sonic Adventure 2 (PC) | Sonic Heroes | Sonic Riders | Sonic the Hedgehog (2006) | Sonic & Sega All-Stars Racing | Sonic Unleashed (Xbox 360/PS3) | Sonic Colours | Sonic Generations | Sonic Forces
Technical information
Sonic Eraser | Sonic 2 (Nick Arcade prototype) | Sonic CD (prototype; 1992-12-04) | Dr. Robotnik's Mean Bean Machine | Sonic Triple Trouble | Tails Adventures | Sonic Crackers | Sonic 3D: Flickies' Island | Sonic & Knuckles Collection | Sonic R | Sonic Shuffle | Sonic Advance | Sonic Advance 3 | Sonic Battle | Shadow the Hedgehog | Sonic Rush | Sonic Classic Collection | Sonic Free Riders | Sonic Lost World
Legacy Guides
The Nemesis Hacking Guides The Esrael Hacking Guides
ROM: Sonic 1 | Sonic 2 | Sonic 2 Beta | Sonic 3

Savestate: Sonic 1 | Sonic 2 Beta/Final | Sonic 3

Sonic 1 (English / Portuguese) | Sonic 2 Beta (English / Portuguese) | Sonic 2 and Knuckles (English / Portuguese)
Move to Sega Retro
Number Systems (or scrap) | Assembly Hacking Guide | 68000 Instruction Set | 68000 ASM-to-Hex Code Reference | SMPS Music Hacking Guide | Mega Drive technical information