Game/GigLine/Source/GigLine/GigLineVehicle.cpp

@@ -1,5 +1,6 @@
 #include "GigLineVehicle.h"
 
+#include "ChaosVehicleWheel.h"
 #include "ChaosWheeledVehicleMovementComponent.h"
 #include "Components/SkeletalMeshComponent.h"
 
@@ -12,6 +13,28 @@ namespace GigLineVehicleDims
 	constexpr float TrackCm = 156.0f;
 }
 
+UGigLineFrontWheel::UGigLineFrontWheel()
+{
+	// Dimensions from the model's report: radius 33 cm, width 22 cm. Steering yes, drive no.
+	WheelRadius = 33.0f;
+	WheelWidth = 22.0f;
+	bAffectedBySteering = true;
+	bAffectedByEngine = false;
+	MaxSteerAngle = 35.0f;
+	SuspensionMaxRaise = 8.0f;
+	SuspensionMaxDrop = 8.0f;
+}
+
+UGigLineRearWheel::UGigLineRearWheel()
+{
+	WheelRadius = 33.0f;
+	WheelWidth = 22.0f;
+	bAffectedBySteering = false;
+	bAffectedByEngine = true;
+	SuspensionMaxRaise = 8.0f;
+	SuspensionMaxDrop = 8.0f;
+}
+
 AGigLineVehicle::AGigLineVehicle()
 {
 	PrimaryActorTick.bCanEverTick = true;
@@ -131,9 +154,10 @@ void AGigLineVehicle::ConfigureWheels()
 	for (const FWheelSpec& Spec : Specs)
 	{
 		FChaosWheelSetup Setup;
-		// FChaosWheelSetup has only the class, the bone and an offset in 5.8 - there is
-		// no per-setup disable flag, and steering/drive flags live on the wheel object.
-		Setup.WheelClass = UChaosVehicleWheel::StaticClass();
+		// FChaosWheelSetup has only the class, the bone and an offset in 5.8 - there is no
+		// per-setup disable flag, and steering/drive flags live on the wheel class.
+		Setup.WheelClass = Spec.bSteer ? UGigLineFrontWheel::StaticClass()
+		                               : UGigLineRearWheel::StaticClass();
 		Setup.BoneName = FName(Spec.Bone);
 		Movement->WheelSetups.Add(Setup);
 	}

Game/GigLine/Source/GigLine/GigLineVehicle.h

@@ -1,11 +1,37 @@
 #pragma once
 
 #include "CoreMinimal.h"
+#include "ChaosVehicleWheel.h"
 #include "WheeledVehiclePawn.h"
 #include "GigLineVehicle.generated.h"
 
 class UChaosWheeledVehicleMovementComponent;
 
+/**
+ * Front and rear wheel classes.
+ *
+ * Chaos reads steering and drive flags from the wheel *object* the setup points at, and the
+ * base `UChaosVehicleWheel` is what the first attempt used - which produced zero wheels
+ * after registration. Giving each axle its own class is also what Unreal's own vehicle
+ * template does, for the same reason: the parameters belong to the class, not to the
+ * instance that arrives later.
+ */
+UCLASS()
+class GIGLINE_API UGigLineFrontWheel : public UChaosVehicleWheel
+{
+	GENERATED_BODY()
+public:
+	UGigLineFrontWheel();
+};
+
+UCLASS()
+class GIGLINE_API UGigLineRearWheel : public UChaosVehicleWheel
+{
+	GENERATED_BODY()
+public:
+	UGigLineRearWheel();
+};
+
 /**
  * The one drivable vehicle in the demo.
  *