Game/GigLine/Source/GigLine/GigLineCharacter.cpp

@@ -15,6 +15,8 @@
 #include "Engine/World.h"
 #include "TimerManager.h"
 #include "Containers/Ticker.h"
+#include "Camera/PlayerCameraManager.h"
+#include "UnrealClient.h"
 #include "HAL/IConsoleManager.h"
 #include "Kismet/GameplayStatics.h"
 #include "Misc/CommandLine.h"
@@ -333,6 +335,7 @@ void AGigLineCharacter::BeginPlay()
 	}
 
 	bWalkForever = FParse::Param(FCommandLine::Get(), TEXT("walk"));
+	bCameraTest = FParse::Param(FCommandLine::Get(), TEXT("cameratest"));
 
 	// `-perf` starts the overlay on: the performance capture and any manual frame
 	// check should not depend on someone pressing F3 first. The built demo has
@@ -346,6 +349,120 @@ void AGigLineCharacter::BeginPlay()
 	}
 }
 
+float AGigLineCharacter::GetThirdPersonArmLength() const
+{
+	return ThirdPersonArm ? ThirdPersonArm->TargetArmLength : 0.f;
+}
+
+FVector AGigLineCharacter::GetThirdPersonCameraLocation() const
+{
+	return ThirdPersonCamera ? ThirdPersonCamera->GetComponentLocation() : GetActorLocation();
+}
+
+void AGigLineCharacter::UpdateCameraCollisionTest(float DeltaSeconds)
+{
+	// A dedicated harness rather than a step inside -qaselftest: the QA timeline is
+	// tightly timed and an added teleport perturbed the reset check by 105 cm.
+	CameraTestElapsed += DeltaSeconds;
+	if (CameraTestPlaced && CameraTestElapsed < 2.0f)
+	{
+		return;
+	}
+	if (!CameraTestPlaced)
+	{
+		CameraTestPlaced = true;
+		UWorld* World = GetWorld();
+		bool bFound = false;
+		if (World)
+		{
+			// Search outward for the nearest blocking wall and take the closest hit.
+			float BestDist = TNumericLimits<float>::Max();
+			FHitResult Best;
+			for (int32 i = 0; i < 16; ++i)
+			{
+				const FVector Dir = FRotator(0.f, i * 22.5f, 0.f).Vector();
+				FHitResult Hit;
+				FCollisionQueryParams Q(TEXT("GigLineCameraTest"), false, this);
+				if (World->LineTraceSingleByChannel(Hit, GetActorLocation(),
+						GetActorLocation() + Dir * 6000.f, ECC_Visibility, Q))
+				{
+					// A wall, not the ground: the first run picked a floor hit and
+					// rotated the pawn to face straight down, so the boom pointed at
+					// open sky and the arm never had anything to collide with.
+					if (FMath::Abs(Hit.ImpactNormal.Z) > 0.5f)
+					{
+						continue;
+					}
+					if (Hit.Distance < BestDist)
+					{
+						BestDist = Hit.Distance;
+						Best = Hit;
+						bFound = true;
+					}
+				}
+			}
+			if (bFound)
+			{
+				// The impact normal points OUT of the wall into open space, so standing
+				// along it and facing along it puts the wall behind us. The first two
+				// attempts used its inverse and faced the pawn into the wall, which left
+				// the boom pointing at open sky and the arm with nothing to collide with.
+				SetActorLocation(Best.ImpactPoint + Best.ImpactNormal * 70.f);
+				LastWallNormal = Best.ImpactNormal;
+				const FRotator Facing = Best.ImpactNormal.Rotation();
+				SetActorRotation(Facing);
+				if (APlayerController* PC = Cast<APlayerController>(GetController()))
+				{
+					PC->SetControlRotation(FRotator(0.f, Facing.Yaw, 0.f));
+				}
+			}
+		}
+		if (!bThirdPerson)
+		{
+			ToggleCamera();
+		}
+		CameraTestPlaced = true;
+		UE_LOG(LogTemp, Warning,
+			TEXT("GigLine CAMTEST placed wall=%d fwd=(%.2f,%.2f) normal=(%.2f,%.2f) collisionTest=%d"),
+			bFound ? 1 : 0, GetActorForwardVector().X, GetActorForwardVector().Y,
+			LastWallNormal.X, LastWallNormal.Y,
+			ThirdPersonArm && ThirdPersonArm->bDoCollisionTest ? 1 : 0);
+		return;
+	}
+
+	UWorld* World = GetWorld();
+	// Measure the spring arm itself, not the camera manager: the arm is what carries
+	// the collision test, and its arm length is the value that must shorten.
+	const float Rest = ThirdPersonBoomLength;
+	const float Arm = GetThirdPersonArmLength();
+	const FVector CameraLoc = GetThirdPersonCameraLocation();
+	const float Shortened = Rest - Arm;
+	const FVector Head = GetActorLocation() + FVector(0.f, 0.f, 60.f);
+	const float Dist = FVector::Dist(Head, CameraLoc);
+	FHitResult Hit;
+	FCollisionQueryParams Q(TEXT("GigLineCameraClear"), false, this);
+	const bool bBlocked = World && CameraLoc.SizeSquared() > 1.0f
+		&& World->LineTraceSingleByChannel(Hit, Head, CameraLoc, ECC_Visibility, Q);
+	// Second trace, from the camera back toward the pawn: if this one IS blocked while
+	// the arm length is still at rest, the spring arm's collision test is not running.
+	FHitResult BackHit;
+	FCollisionQueryParams QBack(TEXT("GigLineCameraBack"), false, this);
+	const bool bBackBlocked = World && CameraLoc.SizeSquared() > 1.0f
+		&& World->LineTraceSingleByChannel(BackHit, CameraLoc, Head, ECC_Visibility, QBack);
+	const bool bClear = !bBlocked || Hit.Distance > Dist - 25.f;
+	const bool bShortened = Shortened > 30.f;
+	UE_LOG(LogTemp, Warning,
+		TEXT("GigLine CAMTEST arm %.0f of %.0f cm (shortened %.0f), cam %.0f cm from head, "
+		     "blocked=%d -> %s"),
+		Arm, Rest, Shortened, Dist, bBlocked ? 1 : 0,
+		(bClear || bShortened) ? TEXT("PASS") : TEXT("FAIL"));
+	UE_LOG(LogTemp, Warning,
+		TEXT("GigLine CAMTEST back-trace blocked=%d dist=%.0f (arm rest %.0f)"),
+		bBackBlocked ? 1 : 0, bBackBlocked ? BackHit.Distance : -1.f, Rest);
+	FScreenshotRequest::RequestScreenshot(TEXT("review-demo-camera-collision"), true, false);
+	bCameraTest = false;
+}
+
 void AGigLineCharacter::ToggleDebugOverlay()
 {
 	static IConsoleVariable* Var = IConsoleManager::Get().FindConsoleVariable(TEXT("gigline.Debug"));
@@ -852,6 +969,11 @@ void AGigLineCharacter::Tick(float DeltaSeconds)
 	Super::Tick(DeltaSeconds);
 	// Speed-driven animation state: correct whether the player walked, was pushed,
 	// or fell, and independent of which input produced the movement.
+	if (bCameraTest)
+	{
+		UpdateCameraCollisionTest(GetWorld() ? GetWorld()->GetDeltaSeconds() : 0.f);
+	}
+
 	WalkForever();
 	UpdateBodyAnimation();
 

Game/GigLine/Source/GigLine/GigLineCharacter.h

@@ -200,6 +200,18 @@ protected:
 	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Input")
 	TObjectPtr<UInputAction> ToggleDebugAction;
 
+	/** Current boom length and camera position of the third-person rig. */
+	float GetThirdPersonArmLength() const;
+	FVector GetThirdPersonCameraLocation() const;
+
+	/** `-cameratest`: back the pawn against a wall and check the boom does not clip. */
+	void UpdateCameraCollisionTest(float DeltaSeconds);
+
+	FVector LastWallNormal = FVector::ZeroVector;
+	bool bCameraTest = false;
+	bool CameraTestPlaced = false;
+	float CameraTestElapsed = 0.0f;
+
 	/** Flips the gigline.Debug console variable that the HUD reads. */
 	void ToggleDebugOverlay();
 

TODO.md

@@ -11,9 +11,13 @@ Actionable task list for this project. This file is the single, central place fo
 
 ## 0.2.3 — Camera clipping fixes (patch)
 
-### Patch tasks
+### Patch tasks - active - session-5598ce7e-27e3-4c64-bb49-c04a4a31ee58 (branch `camera-clip-0.2.3`)
 
-- [ ] Fix remaining camera clipping cases in `0.2.x`.
+- [A] Fix remaining camera clipping cases in `0.2.x`. The spring arm has collision testing on `ECC_Camera` with a 12 cm probe, but **no test had ever exercised it**.
+  - **Harness built:** `-cameratest` finds the nearest wall from the spawn in 16 directions, stands the pawn 70 cm off it facing away (through the controller, because a possessed pawn's actor rotation is overwritten every tick), waits 2 s for the boom, then reports the arm length, whether the boom ends inside geometry, and a back-trace from the camera to the head. It also requests a screenshot so the placement can be checked by eye.
+  - **Inconclusive so far, and the setup is the suspect, not the engine.** Every run reports arm 340 of 340 (no shortening), but **both** traces - head to camera and camera to head - come back clear, so nothing was between the pawn and the boom. That points at the placement: the wall the probe found is not ending up behind the boom.
+  - **Three wrong attempts cost runs and are recorded:** the probe first accepted the floor as a "wall" (a hit whose normal points up), then faced the pawn into the wall by negating the impact normal (the normal points _away_ from the wall), then set actor rotation only, which a possessed pawn discards.
+  - **Next step:** capture and look at the placement screenshot before trusting the arm measurement, then re-run. If, with a wall confirmed behind the boom, the arm still reads 340, the spring arm's collision genuinely is not engaging and that is the `0.2.3` fix.
 - [ ] Tag `v0.2.3` and write `CHANGELOG.md` entry; then remove this section.
 
 ## 0.3.0 — Chaos vehicle, enter/exit, closed driving route (weeks 10–13)