X9

The Camera class (CustomCamera.uc)

The camera class is pretty much straightforward. It consist of a single function called UpdateViewTarget. Create a new file and name it CustomCamera.uc, again replace the extend to extend from Object to Camera. Copy the following code that adds a branching to top down camera mode :

function UpdateViewTarget(out TViewTarget OutVT, float DeltaTime)
{
	local vector            Loc, Pos, HitLocation, HitNormal;
	local rotator           Rot;
	local Actor                     HitActor;
	local CameraActor       CamActor;
	local bool                      bDoNotApplyModifiers;
	local TPOV                      OrigPOV;

	// store previous POV, in case we need it later
	OrigPOV = OutVT.POV;

	// Default FOV on viewtarget
	OutVT.POV.FOV = DefaultFOV;

	// Viewing through a camera actor.
	CamActor = CameraActor(OutVT.Target);
	if( CamActor != None )
	{
		CamActor.GetCameraView(DeltaTime, OutVT.POV);

		// Grab aspect ratio from the CameraActor.
		bConstrainAspectRatio   = bConstrainAspectRatio || CamActor.bConstrainAspectRatio;
		OutVT.AspectRatio               = CamActor.AspectRatio;

		// See if the CameraActor wants to override the PostProcess settings used.
		CamOverridePostProcessAlpha = CamActor.CamOverridePostProcessAlpha;
		CamPostProcessSettings = CamActor.CamOverridePostProcess;
	}
	else
	{
		// Give Pawn Viewtarget a chance to dictate the camera position.
		// If Pawn doesn't override the camera view, then we proceed with our own defaults
		if( Pawn(OutVT.Target) == None ||
		!Pawn(OutVT.Target).CalcCamera(DeltaTime, OutVT.POV.Location, OutVT.POV.Rotation, OutVT.POV.FOV) )
		{
		// don't apply modifiers when using these debug camera modes.
		bDoNotApplyModifiers = TRUE;

		switch( CameraStyle )
		{
			case 'Fixed'            :       // do not update, keep previous camera position by restoring
			// saved POV, in case CalcCamera changes it but still returns false
			OutVT.POV = OrigPOV;
			break;

			case 'ThirdPerson'      : // Simple third person view implementation
			case 'FreeCam'          :
			case 'FreeCam_Default':
			Loc = OutVT.Target.Location;
			Rot = OutVT.Target.Rotation;

			//OutVT.Target.GetActorEyesViewPoint(Loc, Rot);
			if( CameraStyle == 'FreeCam' || CameraStyle == 'FreeCam_Default' )
			{
				Rot = PCOwner.Rotation;
			}
			Loc += FreeCamOffset >> Rot;

			Pos = Loc - Vector(Rot) * FreeCamDistance;
			// @fixme, respect BlockingVolume.bBlockCamera=false
			HitActor = Trace(HitLocation, HitNormal, Pos, Loc, FALSE, vect(12,12,12));
			OutVT.POV.Location = (HitActor == None) ? Pos : HitLocation;
			OutVT.POV.Rotation = Rot;
			break;

			case 'TopDown':
			// fix Camera rotation
			Rot.Pitch = (-90.0f     *DegToRad) * RadToUnrRot;
			Rot.Roll =  0;
			Rot.Yaw =   0;

			Loc.X = PCOwner.Pawn.Location.X;
			Loc.Y = PCOwner.Pawn.Location.Y;
			Loc.Z = PCOwner.Pawn.Location.Z + 320;

			Pos = Loc - Vector(Rot) * FreeCamDistance;

			OutVT.POV.Location = Pos;
			OutVT.POV.Rotation = Rot;
			break;

			case 'FirstPerson'      : // Simple first person, view through viewtarget's 'eyes'
			default                         :       OutVT.Target.GetActorEyesViewPoint(OutVT.POV.Location, OutVT.POV.Rotation);
			break;

			}
		}
	}

	if( !bDoNotApplyModifiers )
	{
		// Apply camera modifiers at the end (view shakes for example)
		ApplyCameraModifiers(DeltaTime, OutVT.POV);
	}
	//`log( WorldInfo.TimeSeconds  @ GetFuncName() @ OutVT.Target @ OutVT.POV.Location @ OutVT.POV.Rotation @ OutVT.POV.FOV );
}

DefaultProperties
{
	DefaultFOV=90.f
}

For more information on the camera, see here.

The custom HUD and the rest !