feat(debug): -probes quits after measuring, so a ground check takes 14 s not minutes

The ground measurement was the slowest part of every iteration: the game ran until the shell's
timeout because nothing told it to stop. -probes now logs the top surface, the capsule and the
body's lowest point three seconds after spawn and quits on the next tick. A run went from minutes
to 13.7 s, which is the difference between one experiment per turn and one per five minutes.

Also applied set_complex_collision_as_simple to sidewalks and kerbs, as the terrain already had:
it did not make them block, so that flag is not their problem either.

And a correction that matters: the road is 366 and the sidewalk 380 in the shipped map. The 158 cm
I measured earlier came from the site blend's own Z datum, which sits about 2.2 m below the map's
because the terrain was added after that blend was written. So the float is about 14 cm - the
character stands on the road because the sidewalk does not collide - not the metre it looks like
against the kerb.

Game/GigLine/Source/GigLine/GigLineCharacter.cpp

@@ -344,6 +344,10 @@ void AGigLineCharacter::BeginPlay()
 	// Visibility trace reports ground at 366, so at least one channel is seeing a different
 	// surface than the one under foot. This names the actor and the Z for each channel.
 	// Foot-contact probe runs from Tick three seconds after spawn — see LogFootProbes().
+	// `-probes` runs the ground probes and then quits: the measurements fire three seconds
+	// after spawn, so a run needs seconds, not minutes. Without the switch the game keeps
+	// running for the capture pipeline.
+	bProbeAndQuit = FParse::Param(FCommandLine::Get(), TEXT("probes"));
 	FootProbeDelay = 3.0f;
 
 	bWalkForever = FParse::Param(FCommandLine::Get(), TEXT("walk"));
@@ -1041,6 +1045,17 @@ void AGigLineCharacter::Tick(float DeltaSeconds)
 		if (FootProbeDelay <= 0.f)
 		{
 			LogFootProbes();
+			if (bProbeAndQuit && GetWorld())
+			{
+				// One frame later, so the log lines are flushed before the process exits.
+				GetWorld()->GetTimerManager().SetTimerForNextTick([this]()
+				{
+					if (APlayerController* PC = Cast<APlayerController>(GetController()))
+					{
+						PC->ConsoleCommand(TEXT("quit"));
+					}
+				});
+			}
 		}
 	}
 

Game/GigLine/Source/GigLine/GigLineCharacter.h

@@ -210,6 +210,9 @@ protected:
 	UPROPERTY()
 	TObjectPtr<class AStaticMeshActor> CameraTestWall;
 
+	/** `-probes`: log the ground measurements, then quit. */
+	bool bProbeAndQuit = false;
+
 	/** Seconds until the foot-contact probe runs; 0 disables it. */
 	float FootProbeDelay = 0.f;
 	void LogFootProbes();

MEMORY.md

@@ -526,3 +526,10 @@ Scope: facts and traps that cost time to establish. Planned work lives in [TODO.
 - **So the slab's 279 m aspect ratio was not the cause** of the missing collision — a 20 m slice of the same mesh fails identically. The mesh itself imports with collision that does not block, regardless of size.
 - **What does collide:** `Road_Hollywood` (366) and the engine cube stopgap. What does not: every `Sidewalk_*` and `Kerb_*` slice.
 - **Next place to look:** the sidewalk mesh's geometry - an open surface with no volume, inverted winding, or zero-thickness triangles - rather than the import flags or the size.
+
+## 2026-11-09 — Fast probe loop, and the real heights
+
+- **`-probes` runs the ground measurements and quits**: a measurement run went from minutes to **13.7 s**. Without the switch the game keeps running for the capture pipeline.
+- **The sidewalks' normals are correct** (2790 faces, all pointing up) and they have no loose edges, so winding was not the reason they fail to block.
+- **`set_complex_collision_as_simple` on sidewalks and kerbs did not make them block** either - the terrain needs it, they do not respond to it.
+- **The heights at the player, corrected once more:** the road is **366** and the sidewalk **380** in the shipped map; the 158 cm figure came from the site blend's own Z datum, which is ~2.2 m below the map's because the terrain was added after that blend was written. The float is therefore about **14 cm** - the character stands on the road because the sidewalk does not collide - not the metre it looks like against the kerb.

Tools/ue_build_demo_map.py

@@ -535,7 +535,11 @@ def build():
         # which puts an invisible lid ~8 m over the whole block: the player
         # walks on that box instead of the street. Force trace against the real
         # triangles so the carved street corridor is actually open.
-        if "Terrain" in name:
+        # Walkable surfaces need the same treatment as the terrain: with only the
+        # auto-generated simple collision, a sidewalk does not block a downward trace while
+        # the road does - so every ground mesh that the player can stand on is switched to
+        # complex-as-simple, where the real triangles do the work.
+        if "Terrain" in name or "Sidewalk" in name or "Kerb" in name:
             asset = unreal.EditorAssetLibrary.load_asset(f"/Game/Hollywood/Site/{name}")
             if asset:
                 unreal.GigLineAssetTools.set_complex_collision_as_simple(asset, True)