skate-3-rust-engine/docs/RUNOUT.md

Runout crash investigation

The Hardcore 360-flip reports at ticks 583 and 378 terminate at MotionGraph behavior 86, AddRunoutAttribs. This operation was unsupported before the difficulty-menu changes. Entering the stock runout graph now succeeds in Easy, Normal and Hardcore. A full-frame regression then exposed the next missing owner: PhysicsGround -> BipedGround has no production adapter yet.

Reference

TU3 dump default_82000000_011B0000.bin, guest base 0x82000000, SHA256 f4aa113eb541bfba03dbc108cf5ab43f58c965b20fa3b82f9c40938a0ad841c4. Registration 0x82F89700 selects factory 0x82BC9BA8; vtable 0x82320BDC has Begin 0x82BBA4A8, Update 0x82BBA770 and empty End 0x82B61BB8. The initializer pair 0x82F85870/0x82F85888 identifies BipedStartAngle/BipedSpeed. Addresses are guest addresses; subtract 0x82000000 for dump offsets.

Observed: Begin reads Skeleton0 (effective animation root Z), SystemReckoning16 (COM velocity), SystemReckoning96 (up), and mirrors through ISkaterAnim slot28. OffBoard331 selects alternate velocity OffBoard128. It uses 0x8286CD88 for the projected signed angle, wraps with the strict fraction > 0.5 condition, converts radians to degrees using word 0x42652EE1, and captures full three-dimensional speed. Update emits the retained values with normalized=false and sequence=-1. End performs no writes.

The game currently publishes the ordinary velocity branch; existing riding/air states leave OffBoard331 at its native reset value. The alternate branch is implemented and tested but requires the future BipedAir output owner.

The host numerical routines follow recovered arithmetic; no hardware-matched 360-flip replay has been recorded. A test-injected runout request verifies the stock animation branch in all three modes, not complete on-foot physics.

Remaining integration

User explicitly selected implementing native on-foot/runout instead of an error-recovery screen. BipedGround requires the contact toolkit (82D811C8 / 82D81610), ground job producer, controller placement/update, skeleton mode4, board manager, state publications, and BipedAir/remount transitions. Existing recovered modules are being compiled and connected; enabling modules alone is not a working BipedGround implementation.

Contact toolkit progress

The compiled offboard modules now include the existing native ground lifecycle, sync, reckoning, board possession, reset animation, stock settings loader and Skeleton mode4 adapter. The retained board transform has a distinct owner, as required by the recovered BipedGround skeleton update.

contact_queries reconstructs82D856C8's three support probes and44 obstacle queries, including reverse rays and the constructor's accumulated float rounding. All41 probe definitions are checked word-for-word against an independently evaluated constructor using the dump above. The game adapter queries actual map triangles through the existing acceleration tree and retains query observations. Nonidentity mesh transforms use the complete geometry path to avoid incorrect world/local-space culling. Authored-floor and empty-space query tests pass.

contact_records ports82D81F80's projection, normal fallback, record routing, flags, distance selection and64-record surface capacity. contact_packet ports 82D2DDD0's reset and82D81610..82D818A0's primary/side-support consumption. Boundary tests cover the strict side-height limits, central-contact requirement, world-Y normal replacement, deep-support flags, lateral-normal fallback and record capacity. These tests validate recovered host arithmetic, not bit-exact Xenon arithmetic or a hardware replay.

contact_promotion now implements82D82498's promotion stage before its final sort, retaining the original vertical-group scan and cursor advancement. contact_segments implements82D83438 and candidate insertion82D82380. The normalization threshold at830BD350 is initialized by82F826F8 from82181A88 (word358637BD); its zero value in the raw dump is not the runtime constant. ground_job implements PreUpdate82D30D30's job fields, contact completion and fallback ordering, twenty-frame teleport suppression, geometry adjustment and retained publication flags. None of these components enables a physical state.

The full contact chain is now connected to real world queries: native record sorting, edge intersections, normal constraints, reduction, segment candidates, slope history and final packet publication. The reduced forward limit reaches packet172, which the subsequent ledge query consumes. Tests cover actual floor queries at speeds0,1,3 and6, along with step and slope boundaries.

Player Update82DB4048 calls refresh82D81610 before state PreUpdate (call at 82DB4094). Reset82D30BD0 and Exit82D30CC0 finish pending queries before clearing the completion latch and classifier history. This ordering is retained in the contact owner. A mesh's stable host identity replaces the original query body's guest pointer; current map providers contain static authored geometry.

Still required: production lifecycle owners and job integration; BipedAir, board possession and remount integration. These component tests do not enable BipedGround or establish end-to-end runout correctness. The production runout transition still fails and the playable binary has not been replaced.