The road was never mis-modelled: a 279 m strip imports with ONE auto-generated convex hull, and a
convex hull's top is the strip's maximum height. A downward trace therefore landed at 366 cm - a flat
lid about 2 m above the visible road, which sits at roughly 152 cm there. That single fact explains
every failed sidewalk fix, the 'road above its own sidewalk' reading, and why the player always ended
up on Road_Hollywood.
Slicing the road the way the sidewalks already were fixes it, and the cross-section is now continuous:
Terrain_DEM 154
Sidewalk_North_07 158
Road_Hollywood_07 158 (was 366)
Two changes had to land together: the road exported in slices, and the map stopped staging the single
Road_Hollywood asset - which still sat on top of the slices and won every trace until removed.
All 23 captures regenerated; the player and the car both stand on a continuous ground plane.
The site exporter now splits sidewalks and kerbs into ~20 m pieces
(SEGMENTED / SEGMENT_M in Art/blender/site/export_site_fbx.py), 56 slices in all, so each has a
bounding box that means something where it stands instead of reporting the highest point on a
279 m slope. They import and stage (63 site meshes in the demo map).
The hypothesis behind it is dead, and that is the useful part: with the invisible sidewalk
stopgap retired, the player now falls to Road_Hollywood at 366 - the slices do not block either.
So the 279 m aspect ratio was never the cause; a 20 m slice of the same mesh fails identically.
The sidewalk geometry itself is what does not collide, and the next place to look is its shape -
an open surface with no volume, inverted winding or zero-thickness triangles - not the import
flags and not the size.
The stopgap retirement stands: the player walks on the road, which is real geometry that does
collide, rather than on an invisible ledge.
The reported fall-through was a misdiagnosis: the player never fell. The
imported Terrain_DEM had only a bounding-box simple collision proxy, so a
downward trace anywhere in the block hit the terrain at Z 819 (the mesh
bbox max) and the street sat under an invisible 8 m lid. Standing on that
box looked plausible, which is why it read as working.
- add UGigLineAssetTools (C++): force CTF_UseComplexAsSimple on a static
mesh. UE 5.8 dropped bUseComplexAsSimpleCollision and Python cannot set
the flag; the builder also saves the asset, since the flag lives there
and a map-only save silently reverts it.
- spawn (-13336, -1150, 600): inside the carved corridor (the cut is a
10.7 m half-width around the road centreline), lands on the road at 456.
- fix ResetToStart returning to the mid-air PlayerStart captured in
BeginPlay: StartLocation is now captured on the first grounded frame.
- HighResShot 1280x720 instead of "1280 720", which is a multiplier.
- add -qaselftest: scripted walk/reset/pause on a core ticker plus a
swept ground transect. Results: walk 746 cm/2 s with Z steady, reset
0 cm from spawn, pause/unpause 1/0, transect 84 samples 0 holes.
- rebase onto main, keeping the frontage materials and placement fixes.
- street_mesh.py: continental zebra markings (0.5 m bars, 0.5 m gaps, 3 m
band) at all three signalised crossings, triangles not quads (FBX SDK
refuses to triangulate the crown-twisted quads), stripes +6 cm above the
DEM so they stay above the road surface; winding flipped so every street
surface faces up (road/sidewalks/markings were 100% down-facing and
invisible in engine once the terrain stopped covering them).
- terrain_from_dem.py: cut a 10.7 m corridor around the Hollywood Blvd
centreline so road, kerbs and sidewalks are not buried under the terrain;
sidewalks themselves cover the transition band, walk-check stays at 0 holes.
- Blender builders save with a writability guard + fatal failure: *.blend
is LFS-lockable and checks out read-only; a failed save previously left
downstream steps building from stale files.
- ue_import_site.py: Crossing_Markings imports with no collision (paint on
the road); ue_build_demo_map.py stages it and chmods the lockable .umap
before saving (save_map silently returned False on read-only maps).
- ue_build_review_map.py: demo-crossing camera moved to the real crossing
(s=130.1 m -> UE -24291,-1340) and fixed the ensure_writable path (was
missing the .umap suffix, so the chmod never fired).
Tools/ue_build_demo_map.py builds /Game/Hollywood/DemoMap: sun, sky, the hero
facade on the building line, six site meshes imported with collision, and a
player start on the north sidewalk. Tools/ue_import_site.py imports the site
FBXs; terrain, road and sidewalks use complex-as-simple so a simple hull cannot
ramp over the kerbs. Art/blender/site/export_site_fbx.py exports one FBX per
object so each can carry its own collision.
Reset (R) and pause (Escape) join the character and the input context: reset
restores the spawn transform and clears momentum, pause is a real game pause that
releases the cursor. DefaultInput.ini captures the mouse on launch.
Three placement defects found by measuring the imported actors rather than
trusting the plan: the spawn was on the wrong sidewalk because the FBX flip
inverts north, a mirror I added to the exporter double-corrected an already
correct sidewalk, and the street meshes only carry part of the north walk - the
rest is terrain.
zwitschi