[Mario Kart Wii] Custom AREA (KMP 0x0B): Custom Gravity (Proof of Concept)

LONG DESCRIPTION WITH FULL DETAILS BELOW!!


Not many players in the Mario Kart Wii community knows (or cares) about the fact that gravity can be modified in the game, making everything feel light (low-gravity like on the moon), or very heavy (high-gravity, as if you try landing on the sun).

However, for a week or two I was wondering if we could change gravity in specific sections of a race or battle map. And after some time of brainstorming, it finally became a reality! Shoutouts to Conradi in the Mario Kart Wii modding community for making this possible!

There are plenty of unused AREA variants inside a course/arena's KMP file (for those who don't know, Mario Kart Wii KMP files are basically a collection of coordinations, for objects, camera pointers, respawn pointers and many, many more; the AREA section is commonly used for cameras but also contains the bloom and blur enabler and force CPU players to recalculate their position to drive properly (to name a few)).
Only a total of 11 different AREA variants are used in the game. This custom AREA variant is now variant number 12!
And if old tools like the KMP Cloud (to read KMP files) doesn't lie, then we can have a total of 256 different AREA variants, making it possible to link them with custom codes, scripts and whatnot!

What you see in Mushroom Gorge is every bouncy mushroom object being replaced with wind (mainly for just visuals, but also an invisible ceiling above them (albeit made a bit jank, but it's for a failsafe if the player gets blown up)). And most of those custom "bouncy mushroom"-wind models have the custom gravity AREA cylinder/box around it. Their gravity "multiplier" use floating points, you can use an online converter like https://gregstoll.com/~gregstoll/floa... in order to convert decimals to float. Higher than 1 causes high-gravity; your jumps will be lower and fall speed will be higher, while values lower than 1 causes low-gravity. Once set, simply get within the AREA's boundaries and see the magic happening in front of your own eyes!

On the custom course Hurry-Scurry Galaxy (made by JadenMKW), I made a custom AREA boundary in the whole course; one big box that sets the gravity to x0.5. Going out those boundaries makes the gravity go back to x1.

PAL version only for now since this is still in a testing phase, but feel free to experiment with this (for custom course/arena creators who know what they're doing):

Configurable Gravity in KMP's AREA section [Conradi]
C25b5208 0000000E
3C60809C 8063D6E8
389E0068 38A0FFFF
38C0000B 3D808051
618C6808 7D8903A6
4E800421 2C030000
EC7EF024 41800028
7C641B78 3C60809C
8063D6E8 3D808051
618C6768 7D8903A6
4E800421 80630004
C0630028 7FC3F378
7FA4EB78 C0430114
FC20F090 C0030148
EC0000F2 00000000

The current bugs so far:
Once respawning in a negative gravity (gravity set below to 0 (which is how I made the character fly up)) causes the player to softlock;
Items and objects don't get affected by those for now, but it is planned.
Another thing that might be considered is setting its first Unknown setting (the ?1 setting you've seen in that smaller KMP Cloud window with the bunch of numbers) to be set as forced movement gravity, like you want to make actual wind-boxes, or make everyone shoot upwards if they're too slow.

Codes I used purely for entertainment:
Fix Offroad Glitch;
Always Can Drift (modified to be able to drift at 25km/h);
Dynamic Gravity v3.1 (modified to make falling faster but increase air-time if holding back)(oh hey, it's compatible with this custom AREA!);
Regular and Super Mini-Turbo Charge Modifiers (Super MT is from Formula Kart Wii with the same charge time, I managed to find the regular mini-turbos myself after that);
Disable Stand-still Mini-turbo;
Always have Single Mushroom (for the testing purposes);
And of course the Unrestricted Vehicle Combo mod.

The modified course models will not be published anywhere, as those were made for testing purposes. Now that you have the information you need, feel free to make your own custom designs. And yes, you can definitely use this concept for underwater physics, too!

Mario Kart Wii (c) 2008 Nintendo