Entry 119

Grass from the yard: model flights

2026-10-168mrender

Filescrates/rugrats/src/world/flights.rscrates/rugrats/src/world/game/things.rsmod.rscrates/rugrats/tests/flights.rs

Floor flag 16 (COL tile byte 4 bit 4) throws up a model, 0x80050b5c. It uses model 1008, looked up through 0x80044b74; it is a tuft of grass.

The flag is on these floors:

• the hub's yard: y 1408, x -2048..51968, z 24576..44800;
• levels 4, 10, 11, 12, 13 and 18.

Level 4 is left out by the callers.

The flight's launch:

• kind 2, flags 0x10502 (gravity 0x500, world collision);
• the model's radius;
• speed 100, within 2048 of up;
• 2000 ms, bounce 1000, spin 3000.

Who calls it. The stand state's handler 0x8005d11c and the walk/run state's handler 0x8005e1f4 both call it, from two places. Each flips its own coin first: the high half's bit 0 of an LCG. The coins live at 0x800c42e0 and 0x800c42ec, seeded 0xa8c0 and 0x2fdd as read on the original. The grass starts at the position of hierarchy slot 16's part, 512 up.

Checked on the original. Tommy was put at (-1536, 708, 30000) in the hub, with UP held. 0x80050b5c ran from 0x8005e4c4 on about every second game frame, and once from 0x8005d80c while standing. The screenshot shows small dark green tufts at his feet.

Model flights. Flights gain Skin::Model (record +0x84 from descriptor +0x50). They also gain the two other angles: +0x20 spins by axis +0x4e and +0x22 by +0x50, while +0x24, the roll, spins by +0x4c. Flights::models hands kind 2 to the game. The game draws each one through models::model_triangles, turned by Trig::euler of (+0x20, +0x22, +0x24) as 0x80087afc does through 0x80020ee0.

Test: the_yard_throws_up_grass puts Tommy at the same spot and has him walk for 40 frames. At least five model 1008 kind 2 flights are in the air.