Retail oracle greps confirmed:
- CSphere::intersects_sphere @ 0x00537ae4 (pc:321692): the ethereal branch
is `void __thiscall` — all paths return void (no COLLIDED). The function
performs a proximity check only; no blocking result is produced.
- CCylSphere::intersects_sphere @ 0x0053b4a0 (pc:324573): same void-return
pattern — ethereal branch calls collides_with_sphere (check only, no slide),
all returns are void = passable.
Change: added `if (sp.ObstructionEthereal) return TransitionState.OK` at the
top of SphereCollision and CylinderCollision in TransitionTypes.cs, mirroring
the void-return semantics of both retail functions. The existing per-object
clear at pc:276989 (line 2837) still fires after the early OK return.
Before this fix: an ethereal-alone NPC/ghost with a Cylinder or Sphere shadow
shape would BLOCK the player (regression introduced when Task 3 made ETHEREAL-
alone fall through ShouldSkip instead of instant-skipping). After: all three
shape types — BSP (via BSPQuery Path 1), Sphere, and Cylinder — correctly pass
through when obstruction_ethereal is set.
Tests: added 4 tests to ObstructionEtherealTests.cs verifying:
- Ethereal Cylinder → passable (sweep passes through, no CollisionNormalValid)
- Ethereal Sphere → passable (same)
- Non-ethereal Cylinder → still blocks (regression guard)
- Non-ethereal Sphere → still blocks (regression guard)
Full Core suite: 1584 pass, 0 fail, 2 skip (pre-existing dat skips).
Pseudocode doc updated with confirmed cyl/sphere ethereal contracts and the
complete set/clear/consume flow summary.
Retail refs:
- CSphere::intersects_sphere @ 0x00537ae4 / acclient_2013_pseudo_c.txt:321692
- CCylSphere::intersects_sphere @ 0x0053b4a0 / acclient_2013_pseudo_c.txt:324573
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>