# Casino road overlap diagnostic r314

The road/building intersection detector flagged the source group
`XB_CASINOD_SIDEA_1A_LL_00` at L4RA Route 530, distance 240. The route pose is
approximately `(-585.55, -410.50, 22.52)`, and the group's transform is centered
near `(-586.11, -411.69, 22.29)`. A top-level exact-triangle check reports a
crossing with the nearby road surface.

Two 1280×720 packaged Chrome captures compare the unmodified scene with the
opt-in `clipRoadIntersectingTriangles` diagnostic. The unmodified scene shows
a narrow paved passage between the casino walls. Triangle clipping removes 44
facade triangles, creating gaps along the lower wall edges while leaving the
walls in the drive view. The existing whole-group filter removes 555 nearby
triangles and opens a much larger gap. Both modified views damage visible
architecture without proving the car's lane is obstructed.

This is a false positive for *blocking* the road: coplanar architectural edges
and road triangles cross near the side boundaries, while the route corridor
continues between the walls. A low-speed drive through the unmodified passage
confirms it is physically traversable in this viewer: holding W for 2.8 seconds
moved the car 13.3 world units from the Route 530, distance 240 start, with no
road failure, building collision, or traffic collision reported by the live
drive state. Therefore neither the whole-group filter nor triangle clipping
is enabled by default. The diagnostic parameter remains available for other
locations, but future placement fixes need a lane-width obstruction check and
visual review rather than treating any triangle intersection as a misplaced
building.

This is a viewer drive-through observation, not proof that the passage's
placement matches retail coordinates or that every approach lane is clear.

Both packaged builds reached `City scene ready` at 34,476 triangles normally
and 34,432 with clipping. The debug counter reports exactly 44 clipped
triangles. Captures:

- Original: `webgl-city/review/images/446-r314-casino-road-overlap-original.png`
- Diagnostic: `webgl-city/review/images/447-r314-casino-road-overlap-triangle-clip.png`