An OPEN door (ETHEREAL_PS 0x4 set on Use) still stopped the player with a
residual threshold block after the collision sweep, despite swinging open
visually.
The resolver runs two collision passes per step: the main sweep and a
step-down (foot-sphere "is there floor?") sub-pass. acdream tested the
ethereal door in BOTH; the main pass cleared it (BSPQuery Path 1 + the
Layer-2 override) but the step-down pass had no escape, leaving a Collided
result at the sill -- the "can-sized cylinder on the ground threshold".
Retail's CPhysicsObj::FindObjCollisions (pc:276795-276806) SKIPS an ethereal
target when sphere_path.step_down != 0 -- it only tests it in the main pass.
So an open door is fully passable everywhere; the swung panel's position is
irrelevant (ethereal = no collision; the swing animation is purely visual).
Port that branch verbatim: an ethereal-for-this-test target (target state &
0x4, OR mover-ethereal vs a non-static target) is `continue`d when
sp.StepDown is set.
Live-verified (user confirmed): the door now blocks 0x while open (0x1000C),
still blocks while closed (0x10008); pre-fix it blocked 217x while open.
Core suite green (1595/0).
(An earlier "animate the door collision" theory was wrong and dropped -- if
collision tracked the swung panel you'd bump the panel in its open position,
which retail does not do. The user caught it.)
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>