The physics asset could not be made from Python (PhysicsAssetFactory exposes no mesh
property), so a small editor-only C++ helper calls FPhysicsAssetUtils::CreateFromSkeletalMesh
- the same code path as the editor's Create Physics Asset action. It produces
PA_Vehicle_Sedan with 6 bodies and assigns it to SK_Vehicle_Sedan.
AGigLineVehicle is a Chaos wheeled pawn that configures its four wheels from the modelled
dimensions (radius 33 cm, wheelbase 278, track 156) and is staged in DemoMap. A run logs:
spawned at (-12950, -900, 120), 4 wheel setups
settled at Z 494 cm, simulating=1, speed=0 cm/s
That last line is the defect and it is not hidden: the vehicle rests 3.7 m above the road,
so the generated physics bodies do not match the mesh. Recorded in TODO.md with the next
step - inspect the bodies against the mesh, then either fix the creation params or author
two boxes and four wheel spheres explicitly.
Chaos drives a skeletal mesh, so the static system split was not drivable on its own. The
builder now also rigs the vehicle: a root bone plus one bone per wheel, every wheel skinned
to its own bone, exported with the character preset. SK_Vehicle_Sedan imports with
SK_Vehicle_Sedan_Skeleton (508 triangles).
Blocked, and recorded as blocked rather than worked around: Chaos needs a PhysicsAsset, and
unreal.PhysicsAssetFactory in 5.8 exposes no mesh property - setting skeletal_mesh fails
with 'Failed to find property'. Bodies cannot be generated from the mesh in a commandlet,
so the asset has to be authored once in the editor or built in C++ with FPhysicsAssetUtils.
Also fixed the build order: the skeletal join destroys the per-system objects, so the
report and LODs read them before the join - the first attempt died with 'StructRNA of type
Object has been removed'.
zwitschi