Cars touch

2026-10-24, the game app's session.

What was tried

The physics session had ported Gold's collisions between cars and the damage, but they read each car's drawn object: its parts, each part's hull and health, and a hull for the whole car. The live race started from the disc had no such objects, so its cars passed through each other. This session built them from the car files.

What was found

• The parts come from the car file's objects. FUN_0046aabc loads the 18 body objects (three sets of six) and the 4 wheels. Each object is followed in the file by seven words: its hull's half sizes, radius and centre. Each body part gets the health held at 0x61ea68, 2,000,000. Sets 0 and 1 each get a one-step chain (FUN_004545a8) that turns a broken part into the same part of the next set. So the three sets the format notes called "damage states or detail levels" are damage states.
• The race object has ten parts, body set 0 and the wheels. FUN_004203c8 (its error string is "Prisme") gives each of them a new hull from its own vertices. It gives the whole car a hull too: the box of all ten parts' vertices. The radius is √(x² + y²) of the two first half sizes, through the game's square-root table.

Measured: every field the collisions and the damage read matches the running game's objects for all eight cars on Beltane. That covers the hulls, the health, the chains and the damaged parts two sets down (crates/pod-world/tests/object.rs). In a minute of the live race on Beltane with the damage by parts, the cars touch 78 times and 37 parts are damaged.

What is next

• When a car falls through the track, the step puts it back on the race paths. The paths are not yet in the world built from the disc.
• The damage record for the race display (FUN_0047ed1c).
• The drivers' trackers (FUN_004aa8a0).