gameplay: walkable demo map, reset and pause

Tools/ue_build_demo_map.py builds /Game/Hollywood/DemoMap: sun, sky, the hero
facade on the building line, six site meshes imported with collision, and a
player start on the north sidewalk. Tools/ue_import_site.py imports the site
FBXs; terrain, road and sidewalks use complex-as-simple so a simple hull cannot
ramp over the kerbs. Art/blender/site/export_site_fbx.py exports one FBX per
object so each can carry its own collision.

Reset (R) and pause (Escape) join the character and the input context: reset
restores the spawn transform and clears momentum, pause is a real game pause that
releases the cursor. DefaultInput.ini captures the mouse on launch.

Three placement defects found by measuring the imported actors rather than
trusting the plan: the spawn was on the wrong sidewalk because the FBX flip
inverts north, a mirror I added to the exporter double-corrected an already
correct sidewalk, and the street meshes only carry part of the north walk - the
rest is terrain.

Game/GigLine/Source/GigLine/GigLineCharacter.cpp

@@ -7,6 +7,7 @@
 #include "GameFramework/CharacterMovementComponent.h"
 #include "GameFramework/PlayerController.h"
 #include "InputAction.h"
+#include "GameFramework/PlayerController.h"
 #include "InputMappingContext.h"
 
 AGigLineCharacter::AGigLineCharacter()
@@ -57,6 +58,8 @@ void AGigLineCharacter::LoadInputAssets()
 	StrafeLeftAction = Cast<UInputAction>(LoadSoft(TEXT("/Game/Input/IA_StrafeLeft.IA_StrafeLeft")));
 	LookAction = Cast<UInputAction>(LoadSoft(TEXT("/Game/Input/IA_Look.IA_Look")));
 	JumpAction = Cast<UInputAction>(LoadSoft(TEXT("/Game/Input/IA_Jump.IA_Jump")));
+	ResetAction = Cast<UInputAction>(LoadSoft(TEXT("/Game/Input/IA_Reset.IA_Reset")));
+	PauseAction = Cast<UInputAction>(LoadSoft(TEXT("/Game/Input/IA_Pause.IA_Pause")));
 
 	if (!MappingContext || !MoveAction || !MoveBackAction || !StrafeAction || !StrafeLeftAction
 		|| !LookAction)
@@ -77,6 +80,9 @@ void AGigLineCharacter::BeginPlay()
 
 	LoadInputAssets();
 
+	StartLocation = GetActorLocation();
+	StartRotation = GetActorRotation();
+
 	// Push the mapping context for this local player.
 	if (MappingContext)
 	{
@@ -124,6 +130,14 @@ void AGigLineCharacter::SetupPlayerInputComponent(UInputComponent* PlayerInputCo
 	{
 		Input->BindAction(LookAction, ETriggerEvent::Triggered, this, &AGigLineCharacter::Look);
 	}
+	if (ResetAction)
+	{
+		Input->BindAction(ResetAction, ETriggerEvent::Started, this, &AGigLineCharacter::ResetToStart);
+	}
+	if (PauseAction)
+	{
+		Input->BindAction(PauseAction, ETriggerEvent::Started, this, &AGigLineCharacter::TogglePause);
+	}
 	if (JumpAction)
 	{
 		Input->BindAction(JumpAction, ETriggerEvent::Started, this, &AGigLineCharacter::StartJump);
@@ -199,6 +213,51 @@ void AGigLineCharacter::Look(const FInputActionValue& Value)
 	AddControllerPitchInput(Axis.Y * LookSensitivity * (bInvertLookY ? -1.0f : 1.0f));
 }
 
+void AGigLineCharacter::ResetToStart()
+{
+	// Reset is a level-restart in miniature: put the body back where it spawned,
+	// clear momentum so a fall does not carry over, and hand control back to the
+	// player if the pause menu was open.
+	if (UWorld* World = GetWorld())
+	{
+		SetActorLocationAndRotation(StartLocation, StartRotation, false, nullptr, ETeleportType::TeleportPhysics);
+		GetCharacterMovement()->StopMovementImmediately();
+		if (AController* Controller = GetController())
+		{
+			Controller->SetControlRotation(StartRotation);
+		}
+		UE_LOG(LogTemp, Log, TEXT("GigLine: reset to start"));
+	}
+}
+
+void AGigLineCharacter::TogglePause()
+{
+	// Pause is a game-pause, not just an input mute: the world stops so physics and
+	// timers do not keep running behind the menu.
+	UWorld* World = GetWorld();
+	if (!World)
+	{
+		return;
+	}
+	bPaused = !bPaused;
+	if (APlayerController* PC = Cast<APlayerController>(GetController()))
+	{
+		PC->SetPause(bPaused);
+		PC->bShowMouseCursor = bPaused;
+		// The two input-mode structs are unrelated types, so branch rather than
+		// using a conditional expression.
+		if (bPaused)
+		{
+			PC->SetInputMode(FInputModeUIOnly());
+		}
+		else
+		{
+			PC->SetInputMode(FInputModeGameOnly());
+		}
+	}
+	UE_LOG(LogTemp, Log, TEXT("GigLine: paused=%s"), bPaused ? TEXT("true") : TEXT("false"));
+}
+
 void AGigLineCharacter::StartJump()
 {
 	Jump();